Cancer mortality among relatives of children with soft-tissue sarcoma: a national survey in Italy.

Information was obtained on the living status or cause of death of 2223 close relatives of 195 children with soft-tissue sarcomas (STS) diagnosed under age 15. Three-hundred nine relatives had died, from all causes, before STS diagnosis in the index child. The expected figure estimated from age- and sex-specific mortality rates in Italy was 293.3. Cancer was reported as cause of death in 76 relatives (75.1 expected). Seven grandmothers, 2 aunts, 1 uncle and 0 mothers died from breast cancer vs. 4.6, 0.9, 0.0 and 0.2 expected. Three siblings died from cancer (0.2 expected, P less than 0.01), i.e. STS, ependymoma and non-Hodgkin lymphoma. These results confirm and expand previous observations that STS in children are associated with other cancers, particularly childhood and breast cancer, in members of the same family.