Second cancer risk in adults receiving autologous haematopoietic SCT for cancer: a population-based cohort study

Population-based evidence on second cancer risk following autologous haematopoietic SCT (HCT) is lacking. We quantified second cancer risk for a national, population-based cohort of adult Australians receiving autologous HCT for cancer and notified to the Australasian Bone Marrow Transplant Recipient Registry 1992-2007 (n=7765). Cancer diagnoses and deaths were ascertained by linkage with the Australian Cancer Database and National Death Index. Standardized incidence ratios (SIRs) were calculated and Cox regression models were used to estimate within-cohort risk factors treating death as a competing risk. During a median 2.5 years follow-up, second cancer risk was modestly increased compared with the general population (SIR 1.4, 95% confidence interval 1.2-1.6); significantly elevated risk was also observed for AML/myelodysplastic syndrome (SIR=20.6), melanoma (SIR=2.6) and non-Hodgkin lymphoma (SIR=3.3). Recipients at elevated risk of any second cancer included males, and those transplanted at a younger age, in an earlier HCT era, or for lymphoma or testicular cancer. Male sex, older age (>45 years) and history of relapse after HCT predicted melanoma risk. Transplantation for Hodgkin lymphoma and older age were associated with lung cancer risk. Second malignancies are an important late effect and these results inform and emphasize the need for cancer surveillance in autologous HCT survivors.