Abbott D, O'Brien S, Farnham JM, et al. - Since there were few reports of the association of other cancers with Ewing sarcoma, a rare tumor occurring most often in the bones or soft tissues of children and young adults, in patients and their relatives, researchers used a resource combining statewide genealogy and cancer reporting to provide unbiased risks. Utilizing a combined genealogy of 2.3 million Utah people and the Utah Cancer Registry, relative risks for cancers of other sites were estimated in 143 Ewing sarcoma individuals using a Cox proportional hazards model with matched controls. However, using internal cohort-specific cancer rates in first-, second-, and third-degree relatives, risks in relatives were estimated. In Ewing sarcoma patients, cancers from three sites (breast, brain, complex genotype/karyotype sarcoma) were found in excess. No patients with Ewing sarcoma were found among Ewing sarcoma patients' first, second, or third-degree relatives. In first-degree relatives, significantly raised the risk for the brain, lung/bronchus, female genital, and prostate cancer was noted. In second-degree relatives for breast cancer, nonmelanoma eye cancer, malignant peripheral nerve sheath cancer, non-Hodgkin lymphoma, and translocation sarcomas, significantly increased risks were seen. Significantly heightened risks were observed for stomach cancer, prostate cancer, and acute lymphocytic leukemia in third-degree relatives. This cancer risk assessment of Ewing sarcoma patients and their relatives shows evidence of some increased predisposition to cancer in this population that can be used to individualize evaluation of future patient treatment and patient and relative screening.