[Li-Fraumeni syndrome and the p53 gene]

81 candidate families with a rare genetic susceptibility to cancer called Li-Fraumeni syndrome were enrolled in an International Working Group. Review of 2,261 blood relatives revealed a total of 515 family members (23%) who had at least one confirmed cancer diagnosis. The major features of the syndrome, breast cancer, sarcomas of soft tissue and bone, brain tumour, leukemia and adrenal cortical carcinoma accounted for 74% of all the cancers recorded. 64% of all malignant tumours occurred before the age of 45 years. Among females, breast cancer accounted for 43 percent of all cases. There were 22 cases of bilateral metachronous breast cancer. Excluding individuals with bilateral breast cancer, 76 patients developed a second neoplasm, the most common being osteogenic sarcoma. The present study agrees with previous reports on the epidemiological aspects of Li-Fraumeni syndrome, the genetic defect of which has recently been found to involve the tumour-suppressor gene p53.