Bone marrow transplants often used to treat leukemia and other malignant diseases dramatically increase the risk of cancer.
The risk can increase by as much as 8.3 times for people who have survived the transplant for 10 years or longer, while children who had transplants before they were 10 faced the greatest risk of all. Overall, the risk was greater the younger the patient was when he had the transplant.
Researchers feel the risk may be linked to the amount of radiation therapy the patients received before having the transplant.
The research team, from the National Cancer Institute at Bethesda, Maryland, studied the records of 19,229 patients given bone marrow transplants between 1964 and 1992. They found that 80 had developed a new cancer compared with an expected 29.8 cases from the general population (New Eng J Med, 1997; 336: 897-904).