CYTOTOXIC DRUGS, CANCER EFFECTS

Cytotoxic drugs (cell-killing drugs) are used primarily for the treatment of cancer or some more serious generalised autoimmune diseases such as rheumatoid arthritis. As far as generalised fitness is concerned, the underlying disease may have more impact on diving than the treatment.

Cancer patients also often have lung conditions that can cause problems such as: chronic lung diseases, opportunistic lung infections, lung metastases, radiation treatment to the lungs (causing fibrosis), pulmonary haemorrhage, pulmonary oxygen toxicity from oxygen therapy, pulmonary toxicity from blood component therapy and graft-versus-host disease.

Fitness and Diving:
After cancer and its treatment, lung tissue is less able to stretch safely, and fibrosis caused by cytotoxics may render the diver more liable to a burst lung on ascent. Certain drugs, such as bleomycin, are contraindications to diving. Bleomycin causes a special type of serious lung fibrosis (and possible adult respiratory distress syndrome) in response particularly to increased levels of oxygen. For anyone treated with this drug, any inspired oxygen level above 0.25 ATA should be avoided.

The cytotoxic drugs may leave residual effects even long after their withdrawal. Functional assessments of both cardiac and pulmonary status by formal testing are important before diving is considered. Life expectancy needs to be assessed before starting dive training.

Medication used in treatment:
The incidence of either pulmonary or cardiac problems is shown in brackets.

Bleomycin (pulmonary 1-10%); Busulfan (pulmonary 1-10%); Carmustine [BCNU] (pulmonary 2-30%); Cytarabine (pulmonary 20%); Mitomycin C (pulmonary 3-10%); Methotrexate (pulmonary, occasional); Chlorambucil (pulmonary, rare); Cyclo-phosphamide (pulmonary, rare); Procarbazine (pulmonary, rare), Adriamycin (cardiac).

(Guy De Lisle Dear MD, Alert Diver, Sept-Oct 1999.)