No increased congenital defect risk from childhood cancer treatments
MedWire News: Children of childhood cancer survivors are not at any increased risk for congenital defects as a result of parental exposure to mutagenic treatments, results from a large US study indicate.
The analysis of children of individuals from the Childhood Cancer Survivor Study found no increased risk for birth defects among those whose parent received treatment involving chemotherapy with alkylating agents and/or radiation of the testes or ovaries, compared with the children of survivors who did not receive such treatment.
Lead author Lisa Signorello (Vanderbilt University, Nashville, Tennessee) commented in a press statement: "Childhood cancer survivors face real reproductive concerns, including unknowns related to the effects of therapy. But, hopefully this study will provide some reassurance that their children are unlikely to be at increased risk for genetic defects stemming from their earlier treatment."
Signorello and colleagues studied data for 1128 men and 1627 women who were 5-year survivors of cancer diagnosed when they were aged younger than 21 years, and their 4699 children.
The survivors provided information about pregnancy history and medical conditions for their biologic children through questionnaires, and the researchers studied medical records of both the survivors and children to review treatment histories and confirm any medical diagnoses.
The team reports that there was no difference in the proportion of congenital anomalies (congenital malformations, single-gene defects, and cytogenetic abnormalities) among children of women exposed to radiation or alkylating agents compared with those exposed to neither, at 3.1% versus 3.5%, respectively.
Nor was there any difference in the risk for congenital anomalies between exposed and unexposed men, at corresponding rates of 1.9% versus 1.7%.
Further analysis showed that there was no association between radiation dose to either ovaries or testes and risk for congenital anomalies, nor between treatment with alkylating agents specifically and congenital defect risk.
American Society of Clinical Oncology spokesperson and pediatric cancer specialist ZoAnn Dreyer (Baylor College of Medicine, Houston, Texas) commented: "As the proportion of childhood cancer survivors within our population grows, it is clear that a very large number of former patients will be impacted by the results of this study… While we as oncologists have felt the risk of congenital abnormalities to be low, we now have concrete data from a very large number of children to support us in our conversations with survivors and newly diagnosed patients.
"These results will reassure survivors that their previous cancer therapy does not appear to result in an increased risk of birth defects in their future offspring."
By Caroline Price