Compiled by JianMin LI
Dec 7, 2005 :Adverse events common after childhood leukemia
Wed Dec 7, 2005 1:20 PM ET
NEW YORK (Reuters Health) - Relapses and second malignancies are relatively frequent in the years following completion of treatment for childhood acute lymphoblastic leukemia (ALL), according to the results of a new study.
New treatment regimens must "not only decrease the rate of leukemic relapse but also decrease the rate of development of second cancer," Dr. Ching-Hon Pui from St. Jude Children's Research Hospital, Memphis, Tennessee told Reuters Health.
Pui and colleagues evaluated the frequency, causes, and predictors of adverse events in 827 children with ALL who had completed treatment with the latest drug regimens between 1984 and 1999.
The overall event-free survival rate was 86.0 percent at five years and 83.1 percent 10 years after treatment was finished, the authors report in the Journal of Clinical Oncology.
The most common cause of treatment failure was bone marrow relapse, followed by the development of a second malignancy.
Being male was the only independent adverse predictor for relapse. Being under the age of 1 year or being more than 10 years old, and having a high white cell count at diagnosis was associated with an increased risk of second malignancy.
"Partly because of the reduction in leukemic relapses," the investigators write, "second malignancies have become a major cause of treatment failure, accounting for almost a third of the adverse events in patients treated at our centers in the mid-1980s."
Pui added that despite earlier findings, current treatments appear to be able to eliminate the adverse impact of male sex. "Boys are doing just as well as girls."
SOURCE: Journal of Clinical Oncology, November 1, 2005.
September 28, 2005: Doctors Make Safer Bone Marrow Transplants
http://www.washingtonpost.com/wp-dyn/content/article/2005/09/28/AR2005092801778.html
By MARILYNN MARCHIONE The Associated Press Wednesday, September 28, 2005; 11:07 PM
-- Doctors seem to have found a way to make bone marrow transplants safer and more effective against blood cancers like leukemia, an achievement that offers new hope for people over 50 in particular.
The advance by Stanford University doctors could make such transplants, which have dramatically improved cancer survival among children and young adults, more widely available to older people who typically don't fare as well.
It also brings the field closer to its Holy Grail _ training a recipient's body to accept tissue from another person and live a "blended" life without heavy reliance on anti-rejection drugs.
Scientists already had achieved this in mice; Stanford researchers now have extended it to people. Their study is published in Thursday's New England Journal of Medicine and was funded by the National Institutes of Health.
Specialists said the study was small and preliminary, but very promising.
"If it works, we would be able to do transplants in a lot more people," said Dr. Mary Horowitz, scientific director of the Center for International Blood and Marrow Transplant Research, based at the Medical College of Wisconsin, which had no role in the research.
Ideally, a leukemia or lymphoma patient would be given radiation or high doses of chemotherapy to destroy the cancerous bone marrow before receiving healthy marrow or blood stem cells from a donor. However, many patients, especially those over 50, die of infections they are unable to fight off before the new marrow takes hold and grows.
To avoid this problem, doctors usually destroy only part of the patient's original marrow. That brings other dilemmas: some cancerous blood cells remain, and the new marrow frequently attacks the old _ an often-fatal problem called graft-versus-host disease.
Stanford researchers developed a way to condition the recipient to accept the new marrow and to inactivate the parts of the patient's immune system that would attack it. They used a combination of low-dose radiation over two weeks and short courses of immune-suppressing drugs.
Only 2 of the 37 patients given the experimental treatment developed severe graft-versus-host disease. Ordinarily, more than half of them would have.
An average of one year later, 27 of the 37 were still alive, and cancer was in complete remission in 24 of them _ better results than usual. The average age of the patients was 52.
"It can achieve the cure of the tumor without the high likelihood that you will come down with the dreaded side effect," said the lead researcher, Dr. Samuel Strober.
The results need to be repeated in larger studies, but are "impressive" and "open a new era in the field," Dr. Gerard Socie, a transplant expert from several universities in Paris, wrote in an accompanying editorial.
Patients also need to be followed for longer than a year to see if they remain cancer-free, Horowitz said.
Bone marrow and blood cell transplants are one reason the death rate from childhood cancers has dropped roughly 50 percent since the 1970s. Leukemia is the most common cancer that children face, but it is diagnosed 10 times more often in older adults _ the very group for whom transplants have been most dangerous.
With the new treatment, "the side effects are being markedly reduced, which is good news for elderly patients with leukemia and lymphoma," Strober said.
The approach also might help people receiving organ transplants if they are "conditioned" with marrow or blood cells from the donor before receiving a kidney or other organ, Strober said.
___On the Net:
New England Journal: http://www.nejm.org
© 2005 The Associated Press
05 June 2005: Power line link to leukemia 'slight'
http://www.theaustralian.news.com.au/common/story_page/0,5744,15517209%255E23289,00.html
Reuters
05jun05
RESEARCHERS have found that proximity to high voltage power lines may be associated with childhood leukemia - but as previously reported in other studies -- the association remains "slight" and "the relation may be due to chance."
There have been several studies over the years that either support or contradict a relationship between electromagnetic fields and cancer. The current study, published in the British Medical Journal, compared approximately 29,000 cases of cancer (including 9700 cases of leukemia) diagnosed before age 15 years in the UK with a similar number of cancer-free "controls" matched for gender, date of birth, and birth registration district.
Dr Gerald J. Draper, at the University of Oxford, and his associates identified subjects living within 1km of 275KV and 400KV overhead power lines.
The team found no association between distance from power lines and overall incidence of cancer. However, children living within 200m of a power line had a 69 per cent higher risk of leukemia than those who lived more than 600m away. Between those two distances, the risk was increased by 23 per cent.
"As this is further than can readily be explained by magnetic fields it may be due to other (causative) factors associated with power lines," the group notes.
In an accompanying editorial, Dr Heather O. Dickinson, from the University of Newcastle upon Tyne, notes that magnetic fields surrounding power lines amounts to "about 1 per cent of the earth's magnetic field, which affects all of us all the time." Thus, the relationships that Draper's group observed may reflect another factor that varies geographically, she suggests.
BMJ science editor Dr Geoff Watts points out that proposed mechanisms supporting a link between electromagnetic fields and cancer "is at best thin and at worst non-existent."
"Before activists begin blowing up pylons, a bit of perspective might help," he adds. Even if such a link exists, he says, Draper's findings indicate that power lines may be associated with only about five cases of childhood leukemia each year.
April 21, 2005: Day Care May Lower Risk of Childhood Leukemia
http://my.webmd.com/content/Article/104/107574.htm
Day Care May Lower Risk of Childhood Leukemia
Exposure to More Children, More Infections Could Be Link
By Michael Smith, MD WebMD Medical News
Reviewed By Brunilda Nazario, MD on Friday, April 22, 2005
April 21, 2005 -- Kids in day care may have a lower risk of developing childhood leukemia, a blood cancer.
A new study provides further support that social activity with other children during the first few months of life protects against later risk of leukemia, say C. Gilham and colleagues.
What's Behind Day Care-Leukemia Link?
What's the apparent link between day care and leukemia risk? It's thought to be infections, say the researchers.
The idea that infections are behind the cause of childhood leukemia dates back to the 1940s.
Leukemia is cancer of white blood cells, immune system cells that fight off infection. In leukemia the bone marrow produces abnormal white blood cells that do not work normally. As the number of abnormal cells grows, they crowd out other blood cells, including normal white blood cells, red blood cells, and platelets. This overcrowding is what leads to symptoms, such as fatigue and bleeding, and can lead to death.
Cancer Success Story
Survival from leukemia varies widely depending on the type. Most children with leukemia have ALL (acute lymphoblastic leukemia).
The improvement in survival for children with ALL over the past 35 years is one of the great success stories of cancer treatment, according to the National Cancer Institute. Today, about 85% of children with ALL live five years or more. Five years is considered the cutoff by cancer experts that indicates likely long-term survival after cancer.
In the current study, Gilham looked at 3,800 children with cancer. Some of the kids had leukemia -- either ALL or another type -- and some had other forms of cancer. They were between 2 and 5 years old when they were diagnosed. Social activity and day care habits were compared with 7,600 children without cancer.
Formal Day Care Protects Most
Interaction with an older infant at least once a week that did not live in the same home was associated with a 34% decreased risk of ALL. Protection from other types of leukemia was similar.
When other types of cancer were taken together there was also a similar level of protection. However, when individual types of cancer were evaluated, risk was decreased only for central nervous system cancers, such as brain cancer.
When the results were looked at more closely, the researchers discovered that the protection from social activity mostly stemmed from formal day care. This included kids who attended day care for any amount of time, a playgroup at least two half-days a week, or at least two half-days a week in a smaller childcare setting with at least four children.
The more social activity or day care the child was exposed to, the lower the risk of ALL. The effect was most pronounced when the child attended day care within the first three months of life.
Infection Important for Child Health
Gilham's study is published in BMJ Online First. Gilham is a statistician at the Institute of Cancer Research in Sutton, England.
The researchers say that some degree of early exposure to infection seems to be important for child health. However, they add that more research is needed to determine the true effect and if the link is associated with any particular infection.
SOURCES: Gilham C. BMJ Online First; pp 1-6. National Cancer Institute.
© 2005 WebMD Inc. All rights reserved.
21 March 2005: NEW $4.1 MILLION STATEWIDE KIDS' CANCER SERVICE
http://www.premier.vic.gov.au/newsroom/news_item.asp?id=552
Children suffering from cancer will get better access to treatment, with fewer trips to hospital and less time spent away from home, under a $4.1 million State Government boost to children's cancer services across the State.
The Premier, Steve Bracks, and Health Minister, Bronwyn Pike, today announced Monash Medical Centre would join the Royal Children's Hospital and Peter MacCallum Cancer Centre as one of Victoria's leading childhood cancer centres.
The plan will not only see Monash upgraded to a major kids' cancer centre ? with extra oncologist sessions enabling more children living in the eastern and south-eastern suburbs to receive treatment closer to home ? but will also become the nerve centre of a new State-wide paediatric cancer service.
"In a local sense, this is a great boost for the people of the eastern and south-eastern suburbs, because it means kids being treated at Monash will have better treatment, more often, " Mr Bracks said.
"But, even more importantly, this initiative will also mean better care for children with cancer across the State, because the new team at Monash will, for the first time, co-ordinate the care of those being treated at the other two cancer centres ? the RCH and Peter Mac."
Ms Pike said previously, different hospitals largely worked separately, meaning the scheduling of a child's cancer treatment was complicated, with children often seeing a myriad of specialists at different institutions.
"Now, a dedicated 10 person cancer team, including nurse co-ordinators, specialist paediatric oncologists and a program co-ordinator, will work to ensure kids are seen by specialists familiar with their care, no matter which hospital they need to visit," she said.
"Kids will benefit because each hospital will now have access to the expertise and skill of specialists at three specialist paediatric cancer centres.
"Nurse co-ordinators will also be able to reduce the number of visits by better scheduling times for different treatments. This will help families by reducing the frequency of travel to hospital."
The new initiative is called the State-wide Paediatric Integrated Cancer Service (PICS). The Government has provided $4.1 million over four years for PICS. This is in addition to the $20 million currently being spent by the Government on boosting general cancer services across the State.
While PICS will be co-ordinated by Monash Medical Centre, it will also see specialists employed at the other two hospitals to improve care for children and support the families.
Mr Bracks said around 200 children are treated each year in Victoria for childhood cancers, including leukaemia. "In the past, childhood cancer treatment at Monash Medical Centre has been limited by a shortage of specialist staff," Mr Bracks said.
"Now, with the appointment of additional paediatric oncologists and a program co-ordinator across the Statewide PICS, Monash will have the extra expertise and resources to expand childhood cancer treatments.
"The focus on paediatric cancer will also give patients and their families improved access to psychological and social support and counselling to help them through difficult times."
Ms Pike said the establishment of the service would also improve liaison with rural and regional hospitals over treatment of child cancer patients from country areas.
"As part of the program, specialists will also be rotated through country hospitals to improve cancer diagnosis for children living in rural and regional areas," Ms Pike said.
The Government also unveiled plans for the new $650,000 Paediatric Day Oncology Unit at Monash Medical Centre, funded by the Kids with Cancer Foundation.
"The new unit will be near the hospital's main entrance which will make it more accessible, providing a child and family-friendly environment," Ms Pike said.
It is expected extra staff will be recruited and the Statewide PICS will begin providing services at the new Unit by July.
As well as funding to establish PICS, the Bracks Government has allocated $6 million for new cancer treatment facilities at the Royal Children's Hospital.
March 21, 2005: Govt boosts funding for children's cancer services
http://www.abc.net.au/news/newsitems/200503/s1328263.htm
The Victorian Government will spend $4.1 million to boost cancer services for children.
The money will fund a team of 10 specialists to co-ordinate the treatment of children with cancer across the state.
The team will be based at a new cancer care centre at the Monash Medical Centre.
Premier Steve Bracks says the money will mean better care for young cancer patients and their families.
"The extraordinary trauma that's there when someone in your family, a young child, your son or your daughter, is diagnosed with cancer - I mean the trauma that's there for you as parents, for the siblings and for others is enormous," he said.
"This is all about making sure we can get better services, better expertise, better research and better co-ordination among the Monash Medical Centre, the Royal Children's Hospital and also the Peter Mac."
March 20, 2005: The benficial powers of darkness
http://www.taipeitimes.com/News/edit/archives/2005/03/20/2003247056
Published on TaipeiTimes http://www.taipeitimes.com/News/edit/archives/2005/03/20/2003247056
The benficial powers of darkness
Artificial light illuminates our lives, allowing us to work or play through the night. But, we toy with our body clocks at severe risk to our wellbeing
By Hugh Wislon
THE GUARDIAN, London Sunday, Mar 20, 2005, Page 9
For many of us, night has become day. We work, travel, shop, exercise and socialize in hours that used to be reserved for relaxation and sleep. Time is a limited resource and, to make full use of it, the night has been illuminated and occupied. Even when we do sleep, street lamps and security lights pierce the darkness.
But our freedom from the natural constraints of day and night may have come at a price. According to a growing band of scientists and doctors, many of us are no longer getting enough darkness in our lives. The theory is based on a simple premise. Our biological rhythms evolved in a time before artificial light, to take advantage of both bright days and dark nights. By succumbing to the temptations of 24-hour living, and ignoring or reducing our natural dark time, we could be putting our health at risk.
"A number of health and environmental problems are due to a loss of darkness," says Dr David Crawford, executive director of the International Dark-Sky Association, a group that campaigns against light pollution. "And it will get worse as we creep -- or rush -- to a 24/7 world. All of life, all of it, has evolved with a day/night cycle -- the circadian rhythm. It's essential to good health. Many studies are now showing that those who go without a true day/night cycle are adversely impacting their immune systems, and that's not good."
Unbalanced
It's not good, but it's becoming the norm. In the UK for instance, more than 20 percent of the working population now work at least some of the time outside the 7am-7pm day. Global travel, the internet, job insecurity, 24-hour shopping and TV, and -- coming soon -- late-night pubs and bars, all help to push back the boundaries of the active day. To remain active at night we need light, with the result that the natural circadian cycle of day and night, light and dark, is becoming perilously unbalanced. We are creating a conflict between what we want to do, and what our internal timekeeper -- the body clock -- prepares us for.
"Our biological clock has been likened to the conductor of an orchestra, with the multiple rhythms of the body representing the various sections of that orchestra," says Russell Foster, professor of molecular neuroscience at Imperial College, London, which later this month hosts the first international sleep conference. "The body clock adapts us for the varying demands of activity and rest. It ensures our internal synchronicity: that our various internal systems -- temperature, alertness, blood pressure and so on -- are working together. And the body clock sets itself using the light/dark cycle. By moving to 24-hour living, and reducing or ignoring the dark bit, we are effectively throwing away the advantages of millions of years of evolution."
The effects of screwing up our body clocks are most readily observable in the growing army of night workers. Studies suggest that, even after years of night shifts, many workers never adjust to a regime that pitches them against our basic and hard-wired biology.
Instead, they head wearily home to bed just as the morning light is prompting their body clocks to prepare for activity, and back again when the gathering dusk tells them to prepare for rest.
Immune Breakdown
Once at work, overriding the craving for dark and sleep comes at a price. "They activate the `fight or flight' stress mechanism," says Foster, "and we know that stress in turn can suppress the immune system." Bright lights, caffeine and nicotine artificially maintain stimulation. Perhaps unsurprisingly, studies show that nightshift workers are at increased risk of a range of health problems, from stress, constipation and stomach ulcers to depression, heart disease and cancer. For example, a 2001 study in Seattle, based on interviews with 800 women, found that females who worked the graveyard shift could face a 60 percent increase in the risk of breast cancer.
There is another theory that tries to explain the high incidence of breast and colo-rectal cancers in shift workers, however.
Melatonin is called "the Dracula hormone" because it always comes out at night. But its production can be severely reduced by bright artificial light. The effects of melatonin on health are not properly understood, but a number of scientists, particularly in America, are connecting low levels of melatonin with high levels of certain cancers in nightshift workers. One study presented to the American Association for Cancer Research found that melatonin can slow tumor growth by up to 70 percent in mice infected with human breast cancer cells.
When the mice were subjected to constant light, cancer growth rocketed.
Some have taken it further. George Brainard, a neurologist at Thomas Jefferson University in Pennsylvania, has recommended that we all exercise a "prudent avoidance" of light at night to ensure normal levels of melatonin whether we work night shifts or not.
No Substitute
Brainard's research has shown that the human body clock can be affected by light of short wavelength, which is more prevalent in artificial light used at night. It also showed that melatonin production was reduced by just this sort of short wavelength light.
Until recently, it was believed that only daylight was strong enough to influence our internal systems.
On the back of this, another researcher has advised parents not to let children sleep with the light on because of a potential - though unproven - connection between artificial light at night and childhood leukemia. The incidence of leukemia in children under five rose by 50 percent in the second half of the 20th century, leading some scientists to point the finger at our increased reliance on artificial light. "I would not myself use a nightlight in a kid's bedroom unless there is a reason for it for safety," said Richard Stevens, a cancer epidemiologist at the University of Connecticut, after a conference on childhood leukemia in London last autumn.
"There is interesting evidence about melatonin having properties that would lead to reduction in cancer risks, so the possibility that this might be related to childhood leukemia is important."
Foster, on the other hand, believes that many of these claims are "overselling" the evidence of melatonin's anti-cancer properties.
"It's true that melatonin is suppressed by light, but in reality we don't really know what effects it has on health. Its anti-cancer properties are a long way from being established as fact," he says.
"My opinion is that the suppression of the immune system is much more likely to explain cancer rates in shift workers."
Embrace the Dark
Nevertheless, most scientists agree that our rush to turn night into day must be having some effect on our health, even if we don't work the graveyard shift. "We now know that we are sensitive to the sort of light levels we readily expose ourselves to in the evening," says Dr Derk-Jan Dijk, director of the Sleep Research Centre at Surrey University. "We're not quite sure what the impact is, but we know that even ordinary room light can have an effect on our physiologies."
A television that flickers all night in a child's bedroom... street lighting that spills through curtains... "There's not enough research on these things at the moment," says Dijk, "but it's certainly a concern. Ideally, we should all be sleeping in darkened rooms. And don't forget, in the natural situation, in which we evolved, dark really did mean dark."
For the general population, the most pressing problem stemming from ubiquitous artificial lighting and 24-hour living is sleep deprivation. The absence of true, continuous darkness could be affecting the quality of our sleep. It's certainly affecting the quantity. We are stretching the boundaries of day at one end, without being able to stretch the boundaries of night at the other.
"I think the critical issue is that sleep has been greatly delayed by our invasion of the night," says Foster. "So we try to manipulate our body clocks with stimulants and sedatives. Caffeine and nicotine keep us awake. Alcohol and hypnotics counteract them when we want to sleep. It's a worrying cycle and the 24-hour society promotes it."
Humans have known for a long time that banishing the dark from our lives has a powerful effect. "Don't forget," reminds Dijk, "continuous light has long been used as a method of torture."
Copyright © 1999-2005 The Taipei Times. All rights reserved.
Jan 31, 2005: U.S. Government List of Cancer-Causing Agents Grows
http://www.newswise.com/articles/view/509518/
Description
The Department of Health and Human Services released the Report on Carcinogens today, adding 17 substances to the growing list of cancer-causing agents. For the first time ever, viruses are listed in the report.
Newswise ? The Department of Health and Human Services released its Eleventh Edition of the Report on Carcinogens today, adding seventeen substances to the growing list of cancer-causing agents, bringing the total to 246. For the first time ever, viruses are listed in the report: hepatitis B virus, hepatitis C virus, and some human papillomaviruses that cause common sexually transmitted diseases. Other new listings include lead and lead compounds, X-rays, compounds found in grilled meats, and a host of substances used in textile dyes, paints and inks.
"Among U.S. residents, 1 in 2 men and 1 in 3 women will develop cancer at some point in their lifetimes. Research shows that environmental factors trigger diseases like cancer, especially when someone has a family history," said Kenneth Olden, Ph.D., director of the National Institute of Environmental Health Sciences and the National Toxicology Program, which prepared the report for DHHS.
The Report on Carcinogens, Eleventh Edition, referred to as the "RoC," lists cancer-causing agents in two categories -- "known to be human carcinogens" and "reasonably anticipated to be human carcinogens." The report now contains 58 "known" and 188 "reasonably anticipated" listings. Federal law requires the Secretary of the Department of Health and Human Services to publish the report every two years.
Six substances have been added to the "known" category:
Hepatitis B virus (HBV) and hepatitis C virus (HCV) are viruses that cause acute or chronic liver disease. They are listed in the report as "known human carcinogens" because studies in humans show that chronic hepatitis B and hepatitis C infections cause liver cancer. Approximately one million United States residents are chronically infected with HBV, which primarily is transmitted through sexual contact (50%) and intravenous drug use (15%).
HCV is the leading cause of liver disease in the United States with more than three million people infected. The major risk factor for hepatitis C infection is illegal intravenous drug use, which accounts for 60 percent of acute infections in adults. The incidence of both hepatitis B and hepatitis C infections is decreasing among United States residents. A vaccine is available for preventing hepatitis B infection but not hepatitis C infection. Infections can also be prevented by screening blood supplies, and by reducing contact with contaminated fluids in health care settings.
Human papillomaviruses (HPVs) are viruses that are sexually transmitted and can infect genital and mucous membranes. Some of these genital mucosal type HPVs are listed in the report as "known human carcinogens" because studies show they cause cervical cancer in women. Approximately 20 million people in the United States are infected with genital HPVs, and 5.5 million new infections occur each year. Most people infected do not have symptoms, but some develop genital warts or cervical abnormalities.
X-radiation and gamma-radiation are listed in the report as "known human carcinogens" because human studies show that exposure to these kinds of radiation causes many types of cancer including leukemia and cancers of the thyroid, breast and lung. The risk of developing cancers due to these forms of ionizing radiation depends to some extent on age at the time of exposure. Childhood exposure is linked to an increased risk for leukemia and thyroid cancer. Exposure during reproductive years increases the risk for breast cancer, and exposure later in life increases risk for lung cancer. Exposure to X-radiation and gamma radiation has also been shown to cause cancer of the salivary glands, stomach, colon, bladder, ovaries, central nervous system and skin.
Of the total worldwide exposure to X-radiation and gamma-radiation, 55 percent is from low-dose medical diagnosis such as bone, chest and dental X-rays, and 43 percent is from natural sources like radon. Other sources, such as industry, scientific research, military weapons testing, nuclear accidents and nuclear power generation, account for about 2 percent.
Neutrons are also listed in the report as a "known human carcinogen." They cause genetic damage similar to that of X-radiation and gamma radiation, and thus can cause the same cancers. Neutron radiation is used less than other types of radiation in industry, medicine, and research. The general population is exposed to neutrons primarily from cosmic radiation that penetrates the earth's atmosphere.
Eleven substances have been added to the "reasonably anticipated" category:
Naphthalene is used as an intermediate in the synthesis of many industrial chemicals, and has been used as an ingredient in some moth repellants and toilet bowl deodorants. Naphthalene is listed in the report as "reasonably anticipated to be a human carcinogen," based on inhalation studies in animals which showed it causes rare nasal tumors in rats and benign lung tumors in female mice.
MeIQ, MeIQx, and PhIP are heterocyclic amine compounds formed when meats and eggs are cooked or grilled at high temperatures. These compounds are also found in cigarette smoke. They are listed in the report as "reasonably anticipated to be human carcinogens" because oral studies in animals showed they caused cancer in multiple organs including the forestomach, colon, liver, oral cavity, mammary gland, skin, and cecum. Several human studies suggest there is an increased risk for breast and colorectal cancers related to consumption of broiled or fried foods that may contain these or other similar compounds.
MeIQ is 2-Amino-3, 4-dimethylimidazo [4,5-f]quinoline MeIQx is 2-Amino-3, 8-dimethylimidazo [4,5-f]quinoxaline PhIP is 2-Amino-1-methyl-6-phenylimidazo [4,5-b]pyridine
Lead is used to make lead-acid storage batteries, ammunition, and cable coverings. Lead compounds are used in paint, glass and ceramics, fuel additives, and in some ethnic and ceremonial cosmetics. The report lists lead and lead compounds as "reasonably anticipated to be human carcinogens" because exposure to lead or lead compounds is associated with a small increased risk for lung or stomach cancer in humans, and cancer of the kidney, brain or lung in studies with laboratory animals.
Cobalt Sulfate is used in electroplating, as coloring agents for ceramics, and as drying agents in inks and paints. Cobalt sulfate is listed as "reasonably anticipated to be a human carcinogen" based on inhalation studies in laboratory animals that showed it causes adrenal gland and lung tumors.
Diazoaminobenzene is a chemical used as an intermediate in the production of dyes and to promote adhesion of natural rubber to steel. Diazoaminobenzene is listed as "reasonably anticipated to be a human carcinogen" based on evidence that it is metabolized to benzene, a "known human carcinogen," and because it causes genetic damage in laboratory animals.
Nitrobenzene is a chemical used mainly in the production of other industrial chemicals. It is listed as "reasonably anticipated to be a human carcinogen" because inhalation studies of this compound produced cancer in experimental animals.
1-Amino-2, 4-dibromoanthraquinone is a vat dye that is used in the textile industry. It is listed as "reasonably anticipated to be a human carcinogen" based on evidence that it causes cancer in experimental animals.
4,4'-Thiodianiline has been used as an intermediate in the preparation of several kinds of dyes. It is listed as "reasonably anticipated to be a human carcinogen" based on evidence that it causes cancer in experimental animals.
Nitromethane is used in specialized fuels, explosives, and in the synthesis of pharmaceuticals and agricultural chemicals. It is listed as "reasonably anticipated to be a human carcinogen" based on evidence that it causes cancer in experimental animals.
The Report on Carcinogens, Eleventh Edition, is prepared by the National Toxicology Program, an interagency group coordinated by the U.S. Department of Health and Human Services. The full report is available at the NTP website http://ntp.niehs.nih.gov.
The National Toxicology Program is located at the National Institute of Environmental Health Sciences (NIEHS) in Research Triangle Park, NC. Part of the National Institutes of Health, NIEHS looks at factors in the environment that may be harmful to human health.
© 2005 Newswise. All Rights Reserved.
1 Dec 2004: FDA Panel OKs Childhood Leukemia Drug
Wed Dec 1, 1:31 PM ET
WASHINGTON - Federal health advisers on Wednesday recommended approval of the first new cancer drug in the past decade specifically aimed at treating the most common childhood leukemia.
The panel, an advisory arm of the Food and Drug Administration (news - web sites), stopped short of recommending approval of Clolar for treatment of another form of leukemia, however, saying more proof was needed of the drug's clinical benefit.
Clolar was approved for treatment of children from age 1 to 21 with refractory or relapsed acute leukemias who have exhausted other treatment options.
Jeffrey Buchalter, president and chief executive officer of Ilex Products Inc., the drug manufacturer, said the federal advisers' decision not to recommend approval of Clolar to treat acute myelogenous leukemia may be subject to change.
"We think this drug has potential," he said. "The issue is they need more data ... that the drug provided a clinical benefit. We've very interested in working with the FDA (news - web sites)."
While the FDA is not bound to follow the guidance of its Oncologic Drugs Advisory Committee, the agency typically heeds its federal advisers' recommendations.
About 3,830 new cases of acute lymphocytic leukemia, the most common type of leukemia in children younger than 19, are diagnosed each year in the United States. The disease arises due to genetic injury to the DNA of a single cell in the bone marrow. According to the Leukemia and Lymphoma Society, acute leukemia is a rapidly progressing disease affecting unformed and immature cells.
Ilex is a unit of San Antonio, Texas-based Ilex Oncology, which is being purchased by Cambridge, Mass.-based Genzyme.
___
On the Net:
Ilex Oncology: http://www.ilexonc.com/
26 October 2004: New analysis links breastfeeding to reduced risk of childhood leukemia
http://www.berkeley.edu/news/media/releases/2004/10/26_breastfeeding.shtml
By Sarah Yang, Media Relations | 26 October 2004
BERKELEY - Babies who are breastfed have a lower risk of developing childhood leukemia, according to a new analysis of 14 studies by researchers at the University of California, Berkeley.
The paper, to be published November in the journal Public Health Reports, found that breastfeeding was linked to lower risks of both acute lymphoblastic leukemia (ALL), the most common of the childhood cancers, and acute myeloblastic leukemia (AML).
"Our paper is the first to systematically review the epidemiologic evidence of the link between maternal breastfeeding and the risk of childhood leukemia," said Marilyn Kwan, UC Berkeley post-doctoral researcher in epidemiology at the School of Public Health and lead author of the study. "We conducted this meta-analysis because the studies that had been conducted previously have been inconclusive and contradictory. Our review of the scientific literature shows that the evidence is definitely pointing towards the benefits of breastfeeding when it comes to the risk for two kinds of childhood leukemia, ALL and AML."
The 14 case-control studies, taken from around the world, were published between 1988 and 2003. They included 6,835 cases of ALL and 1,216 cases of AML.
While the causes of childhood leukemia are not completely understood, it is believed that the disease begins with a genetic change that occurs while the fetus is in the womb. This theory is supported by researchers, led by Mel Greaves of London's Institute of Cancer Research, who studied blood samples taken at birth and found the presence of an abnormal fusion of two genes, TEL and AML1. The cause of the gene fusion is not certain, said Kwan, but it has been shown to interfere with the normal formation and development of blood cells in animals and is found in 25 percent of children with leukemia.
The genetic abnormality does not guarantee that a child will go on to develop leukemia, said the researchers. Studies indicate that only 1 in 100 children with the gene fusion at birth go on to develop the disease.
"The gene fusion in and of itself doesn't cause leukemia," said Kwan. "There needs to be a second promoting step, a rare response in the child to early infections that can cause a secondary genetic change. That's where breastfeeding may come into play. It could be preventing that second event from occurring because the mother is passing along her antibodies to the child through her breast milk and strengthening the baby's immune system."
According to the National Cancer Institute, leukemia is the leading cause of cancer deaths in the United States among children younger than 15. From 1975 through 1995, ALL accounted for 78 percent of U.S. childhood leukemia cases, while AML accounted for 16 percent of cases. The bone marrow of both ALL and AML patients produces too many immature cells that fail to develop into mature white blood cells.
One of the 14 papers reviewed at UC Berkeley included a small case-control study authored by Kwan as part of the Northern California Childhood Leukemia Study. That study was funded by the National Institute of Environmental Health Sciences and led by Patricia Buffler, a UC Berkeley professor of epidemiology who also is co-author of the analysis.
Encouragingly, the analysis indicates that even short-term breastfeeding, for less than six months, was linked to a lower risk of ALL.
"Our data suggest that breastfeeding for even a short period of time is protective," said Buffler.
"That's actually not surprising. We know that much of the protection provided by maternal antibodies comes in the first couple of months of breastfeeding, so even breastfeeding for three months is beneficial."
The researchers found no significant association between short-term breastfeeding and AML.
While the classification of ALL in the analysis is straightforward, the researchers pointed out that the classification of AML is more variable. Four of the 14 studies specified "other leukemia" or "acute non-lymphoblastic leukemia," which the researchers categorized as AML since it represents the majority of non-ALL cases. However, the researchers acknowledged that the classification method somewhat limits the conclusions they can draw about the impact of breastfeeding on AML.
In addition, the researchers noted the inherent limitations of the case-control studies in the meta-analysis. The people in control groups in such studies tend to have a higher socio-economic status than those in case groups, the researchers said. They say that people of higher socio-economic status tend to be more educated about health issues and more willing to participate in epidemiological studies. They add that women with a higher socio-economic status also tend to report higher rates of breastfeeding.
The researchers said that larger cohort studies are needed to determine whether breastfeeding truly has a protective effect on childhood leukemia risk.
One such cohort study may be the U.S. National Children's Study, which examines the environmental influences on the health and development of more than 100,000 children across the United States. Participants in the study will be followed from birth until age 21. Preliminary results of the study are expected as early as 2008.
Nevertheless, authors of the meta-analysis said there is now enough evidence on the reduced risk of childhood leukemia to recommend breastfeeding. They also cited the other health benefits breastfeeding imparts to the child.
"The overall risk of a child developing leukemia is relatively small, so based upon this analysis, people shouldn't be made to feel guilty if they can't breastfeed," said Dr. Vincent Kiley, a pediatric oncologist with Kaiser Permanente and co-author of the paper. "But if you're on the fence about it, this study provides one more reason to encourage women to breastfeed, even if it is for just a couple of months."
Barbara Abrams, UC Berkeley professor of epidemiology, is another study co-author.
September 25, 2004: With More Night Light Comes A Greater Risk of Leukemia
http://www.mercola.com/2004/sep/25/light_leukemia.htm
Experts are evaluating the possible link between childhood leukemia and too much light at night.
More and more children are diagnosed with leukemia, following a noticeable spike happening in those younger than 5 years old. For them, the risk of developing this cancer increased by more than 50 percent during 1950-2000.
Why leukemia strikes children is not known. However, experts think environmental factors may be the source of the 20th century rise. If they are right, then it may be possible to identify causes -- like light at night -- and prevent the disease. Researchers point to light as one of these factors because modern people are exposed to more light than in the past. Light at night disrupts the natural hours of darkness our bodies need to produce proper levels of melatonin.
Sleep -- also known as natural circadian rhythm -- is an important part of overall health because of this hormone, which protects DNA from damage. Experts say low melatonin has been known to instigate and promote cancer growth.
Several studies have concluded that people who work at night are more likely to develop breast cancer. Also, experts note that blind people, who are not vulnerable to light at night, have a lower incidence of cancer.
Researchers plan to look at the association between biological clocks and light receptors in the human eye, and how sleep patterns, alertness, mood, physical strength and blood pressure are affected. They also will examine another possible cause of childhood leukemia -- magnetic fields, which also may decrease melatonin levels.
EurekAlert September 8, 2004
-- -- -- -- -- -- -- -- --
Dr. Mercola's Comment:
This link between light and leukemia isn't surprising to me because light exposure at night can reduce melatonin levels, which increases your risk of cancer. Young children are exposed to several forms of light at night -- including night-lights and television.
Children, teens and adults should not watch TV before bed. Better yet, get the TV out of the bedroom or even out of the house, completely. It is too stimulating to the brain and it will take longer to fall asleep. When light hits the eyes, it disrupts the circadian rhythm of the pineal gland and production of melatonin and seratonin.
There also should be as little light as possible in the bedroom and, if you get up in the middle of the night, in the bathroom.
If you are lacking melatonin, I do not recommend supplements. It is best to increase levels naturally with exposure to bright sunlight in the daytime (along with full spectrum fluorescent bulbs in the winter) and absolute complete darkness at night.
One of the other important things you can do to maximize the production of melatonin and decrease your risk of cancer is to make sure that you have exposure to bright sunlight during the daytime. Indoor lighting just won't cut it. At night it is important to sleep in pitch dark. You should not be able to see your hand in front of your face ten minutes after you turn out the light. Most people will require black out shades and/or drapes to achieve the level of darkness.
Maintaining your internal clock is important to health. Simply, a full night's sleep is key to your health.
Sep 6, 2004: Environment May Be Linked to Rising Leukemia
Mon Sep 6, 2004.
By Patricia Reaney
LONDON (Reuters) - Pesticides or chemicals in the environment may be behind the steady rise in cases of childhood leukemia, which have increased five-fold since the early 1900s, scientists said on Monday.
Fewer children actually die from the blood cancer than 40-50 years ago but cases have increased about one percent per year in the last half century.
"It represents a five-fold increase," Professor Michel Coleman of the London School of Hygiene and Tropical Medicine told a conference delving into the causes of the increase.
From about 10 cases per million population in England and Wales in 1911-1915, cases rose to about 46 per million at the end of the century.
"The evidence suggests a steady increase in the occurrence of leukemia in this country and in others," said Coleman.
Leukemia is the most common childhood cancer, accounting for nearly one-third of all cases. Most of the rise is in children aged 1 to 4.
Boys have about a 10 percent higher risk of developing the disease, according to Coleman.
Professor Denis Henshaw of the University of Bristol in south-western England and chairman of the conference, said a possible cause could be environmental agents or chemicals that were not around 50 years ago.
Children are thought to be predisposed to the illness at birth by something that occurs in the womb but they do not develop it unless it is triggered by causes as yet unknown.
Ionising radiation, electromagnetic fields, viruses, infections and chemicals and pesticides are thought to be possible triggers.
Professor Alan Preece, also from the University of Bristol, presented research showing the unborn child is particularly sensitive to the effects of exposure to such agents.
In laboratory and animal studies, Preece found levels of such compounds were higher in the fetus than in the placenta or the mother.
"The environmental agents cross the placenta and accumulate in certain foetal organs, varying according to the nature of the agent," Preece said.
"The exact levels are as yet unknown but we know that childhood leukemia is initiated in utero and this could well be a factor in the initiation."
More than 200 doctors and specialists are attending the week-long meeting, organized by Children with Leukemia, Britain's leading charity devoted to conquering the illness.
2001-05-21: Novel, Even Unlikely Drugs May Curb Childhood Leukemia
http://www.sciencedaily.com/releases/2001/05/010521071538.htm
Source: Childrens Hospital Of Philadelphia Date: 2001-05-21 URL: http://www.sciencedaily.com/releases/2001/05/010521071538.htm
Novel, Even Unlikely Drugs May Curb Childhood Leukemia
Philadelphia, Pa. -? While survival rates for childhood leukemias have soared in the past 30 years, about a quarter of pediatric cases remain stubbornly resistant to treatment. As a new attack strategy, scientists are adapting recent discoveries about cell development to coax leukemia cells back to normal growth patterns or to reprogram them into committing suicide.
"Reaching the next level of leukemia treatment will require many new approaches that draw upon our expanding knowledge about how healthy cells differentiate during normal growth and development," said Beverly Lange, M.D., director of experimental therapeutics within the Division of Oncology at The Children's Hospital of Philadelphia, who is an expert in these new attack strategies.
Unlike conventional cancer drugs, the newer drugs are based on detailed knowledge of cellular mechanisms that can be used to manipulate cancer cells in a way that is gentler to surrounding healthy cells.
Oncologists at Children's Hospital are investigating a number of novel, even unlikely, drugs as highly specific, less toxic weapons against childhood leukemia. For example:
-- A form of vitamin A is being used to reprogram a cancer cell into becoming a harmless, normal white blood cell.
-- Borrowing from its use in traditional Chinese medicine, carefully controlled doses of arsenic can trigger cancer cells to commit suicide by mimicking the normal developmental process of "apoptosis," or programmed cell death.
-- A new type of leukemia drug, the bioengineered compound Glivec, can block the genetic signals that direct cancer cells to grow, while leaving normal cells largely unharmed.
-- The naturally occurring protein interleukin-2 may kick-start the body's immune system to better fight leukemia.
Taming cancer cells
Some experimental new treatments rely on methods that neutralize or disrupt cancer cells rather than killing them outright in a frontal attack. "Most conventional cancer drugs rely on lysis, in which a direct attack by the drug causes the cancer cell to burst and die," Dr. Lange explained. But cells may also die through indirect methods that target cancer cells while sparing normal cells.
One such method is terminal differentiation, in which a cell enters a mature stage, with a limited lifespan. For example, all-trans-retinoic acid, a form of vitamin A, is used in this way against the diseased blood cells found in acute promyelocytic leukemia (APML). Rather than directly killing the cancer cell, all-trans-retinoic acid forces the cell to differentiate into a mature white blood cell by reprogramming its genetic mechanisms. It redirects the cancer cell into behaving like a normal blood cell rather than an immortal, constantly dividing cancer cell. "At the same time it dooms the cell, because mature white blood cells live for only 12 hours," said Dr. Lange.
Arsenic and cell suicide
When all-trans-retinoic acid does not work against APML, low doses of arsenic may be helpful, using a different cellular mechanism. By targeting a receptor on the surface of the cancer cell, arsenic triggers the process of "apoptosis," or programmed cell death.
This suicide apparatus resides in all cells as a set of proteins that remain dormant until set in motion by molecular signals specific to each type of cell. In early embryonic development, apoptosis sculpts tissues by eliminating unneeded cells. Throughout life, it serves to destroy diseased or nonproductive cells. However, cancer cells may fail to respond to apoptosis signals and become immortal and deadly.
Arsenic can reset the genetic machinery, permitting apoptosis to seal the fate of cancer cells. At the same time, the low dose of arsenic spares healthy cells. Both arsenic and all-trans-retinoic acid are derived from compounds used in traditional Chinese medicines. "Although APML is a relatively rare disease," said Dr. Lange, "these treatments may be useful in other cancers as well."
Blocking cancer signals
News reports over the past year have heralded highly encouraging results from clinical trials of Glivec (STI-571) for adults with chronic myeloid leukemia (CML). Glivec represents a new class of drugs called signal transduction inhibitors that block the signaling pathways that cause cancer cells to grow. It is bioengineered to zero in on a cell receptor present in leukemia cells that carry a genetic defect called the Philadelphia chromosome.
This targeted approach causes minimal side effects to healthy tissue. While CML is rare in children, the same genetic defect found in CML, the Philadelphia chromosome, occurs in an aggressive form of childhood acute lymphoblastic leukemia (ALL).
Directed by Dr. Lange, Children's Hospital is testing Glivec against that treatment-resistant form of ALL. Through its participation in the Children's Oncology Group, a collaborative national organization that pools data and expertise from many cooperating cancer centers, Children's Hospital is currently conducting pediatric trials of the drug. Because studies have suggested Glivec may have wider applications against other types of cancer, Children's Hospital will test it later this year in children with highly malignant brain tumors.
Boosting immune effects
Also under the umbrella of the Children's Oncology Group, Dr. Lange is leading tests of interleukin-2 (IL-2), a compound that occurs naturally in the body. IL-2 is an immune system protein that plays an important role in an immune response that occurs after a bone marrow transplant. In the "graft vs. leukemia effect," IL-2 stimulates the body's natural killer cells to attack leukemia cells and drive the disease into remission.
The pediatric clinical trials led by Dr. Lange will test whether providing IL-2 can confer this benefit against acute myeloid leukemia (AML) in the absence of a marrow transplant. If so, said Dr. Lange, the approach may help children with AML who do not have a sibling donor for a transplant.
This story has been adapted from a news release issued by Childrens Hospital Of Philadelphia.
Page first set up on Nov 30, 1999 by Jian-min LI. Your feedback (to jmli@telstra.com ) will be very much appreciated.