Genetic disease in offspring of long-term survivors of childhood and adolescent cancer.

Numerous case series have addressed the concern that cancer therapy may damage germ cells, leading to clinical disease in offspring of survivors. None has documented an increased risk. However, the methodological problems of small series make it difficult to draw firm conclusions regarding the potential of cancer treatments to damage the health of future offspring. We conducted a large interview study of adult survivors of childhood cancer treated before 1976. Genetic disease occurred in 3.4% of 2,198 offspring of survivors, compared with 3.1% of 4,544 offspring of controls (P=.33; not significant); there were no statistically significant differences in the proportion of offspring with cytogenetic syndromes, single-gene defects, or simple malformations. A comparison of survivors treated with potentially mutagenic therapy with survivors not so treated showed no association with sporadic genetic disease (P=.49). The present study provides reassurance that cancer treatment using older protocols does not carry a large risk for genetic disease in offspring conceived many years after treatment. With 80% power to detect an increase as small as 40% in the rate of genetic disease in offspring, this study did not do so. However, we cannot rule out the possibility that new therapeutic agents or specific combinations of agents at high doses may damage germ cells.