Radiation and chemotherapy given to young cancer patients don't seem to increase the risk that their own children will have birth defects years later, according to a new study. Researchers said the finding was "reassuring" because some doctors have wondered if powerful drugs and radiation -- especially radiation directed near the ovaries or testicles -- might have long-term effects on egg and sperm cells' DNA. This information will be helpful for young cancer survivors planning to have children. Journal of Clinical Oncology, online December 12, 2011.