RESUMO
Family history of cancer and features of the Li-Fraumeni syndrome (LFS) were investigated in 42 patients with soft tissue sarcoma or osteosarcoma in a pediatric hospital in Mexico City, and compared with 42 non-cancer children. Six subjects with cancer were found among 204 first-degree relatives of cancer patients while there were none among 183 first-degree relatives of non-cancer children. In three families, the proband had two affected relatives, and the type of neoplasia as well as the age of onset suggested the clinical diagnosis of LFS. Our results show that 7.1 percent of our pediatric patients with soft tissue sarcoma or osteosarcoma may belong to LFS families. The authors encourage pediatric and adult oncologist to pay more attention to the history of cancer in nuclear families for eventual hereditary cancer syndrome identification and cancer prevention