Risk of cancer was studied prospectively in four families described in 1969 as having diverse neoplasms, especially breast cancer and soft-tissue sarcoma. Between 1969 and 1981, in ten of 31 surviving family members, there developed 16 additional cancers (expected, 0.5). There were five breast carcinomas, four soft-tissue sarcomas, and seven other cancers. In eight patients, multiple primary cancers developed, including three softtissue sarcomas and one mesothelioma at sites of prior radiotherapy.
Li FP, Fraumeni JF. Prospective Study of a Family Cancer Syndrome. JAMA. 1982;247(19):2692-2694. doi:10.1001/jama.1982.03320440040031