One in every 250 people will be a survivor of childhood cancer. However, what kind of future can they look forward to? Studies show that childhood cancer treatment may well get rid of the original cancer, but such survivors are also more prone to cancer in other sites as adults.
One team of researchers has calculated that as many as one-third of female childhood cancer survivors develop breast cancer by the time they are 40 (N Engl J Med, 1996; 334: 745-51).
There is also evidence that children treated for one type of leukaemia go on to develop another form of the disease as adults (N Engl J Med, 1991; 325: 1682-7).
Most recently, a study based on a follow-up of 13,581 children and adolescents from 25 hospitals in the US and Canada who had survived for at least five years after treatment for leukaemia and other cancers made startling reading. Breast cancer was 16 times more common than expected and often occurred when women reached their late 20s and 30s. Bone cancer was 19 times more common than usual and thyroid cancer 11 times more common among the cancer survivors. The highest extra cancer risk was seen in children who had been treated for Hodgkin's disease. They had an almost 8 per cent chance of new cancer during 20 years of follow-up. The researchers believe chemotherapy and radiation were largely to blame (J Natl Cancer Inst, 2001; 93: 618-29).
Chemotherapy also causes late heart problems, particularly in women (N Engl J Med, 1995; 332: 1738-43). In one study, nearly a quarter of patients treated with anthracyclines developed cardiac abnormalities years later (JAMA, 1991; 266: 1672-7). It can also cause late liver toxicity in long-term survivors of Hodgkin's (Oncology, 1996; 53: 73-8) as well as lung cancer.