Genetic Susceptibility and Risk of Second Cancers in Patients Who Have Undergone Stem Cell Transplant for Cancer

Inclusion Criteria: CASES are those who: * Survived at least 100 days post-hematopoietic stem cell transplantation (HSCT). * Developed an SMN after that time point. * And received TBI as part of the preparative regimen. CONTROLS are randomly selected: * In a 4:1 ratio to cases from the same cohort of 100 day + survivors of HSCT who received TBI. * Controls will be matched to the cases by race and primary diagnosis. * In addition, they must have survived for at least the elapsed time between the case's HSCT and the secondary cancer, without development of an SMN. * We are matching on primary diagnosis, as genotype or radiation sensitivity may predispose to specific primary cancers, as well as the SMNs. * We are matching on race, as allele frequencies vary widely across ethnic groups. Exclusion Criteria: * Did not survive at least 100 days post-hematopoietic stem cell transplantation (HSCT). * Did not develop an SMN after that time point. * Did not receive TBI as part of the preparative regimen.