Competing causes of death in patients with neuroendocrine tumor.

Abstract

e23009 Background: Increasing survival of patients with neuroendocrine tumors (NETs) may be associated with higher risk of mortality due to causes other than the primary NET, namely the competing causes of death (CCD). Therefore, our study focused on comprehensively investigating the magnitude of the CCD on the overall NET mortality and the associated demographic, clinicopathologic and treatment factors using data from the Surveillance, Epidemiology, and End Results (SEER) database. Methods: Patients with histologically confirmed primary NET diagnosed from 1973 through 2015 were identified using the SEER-9 registries for subsequent data collection and analysis. CCD were stratified and analyzed using standardized mortality ratios (SMRs) as measures of the relative risks of mortality for NET patients in comparison to the general population in the US adjusted by age, sex and race over the same time period. Competing risk regression analysis was performed using Fine and Gray multivariate regression model. Results: A total of 29,981 NET patients were included, 5481 (42.5%) of which deceased due to CCD. Overall SMR attributed to CCD was 2.50 [95% Confidence interval (CI): 2.43–2.56]. The SMR of non-cancer CCD was 2.65 (95% CI:2.58–2.73) and that of SPN was 1.91 (95% CI:1.79–2.04). Heart diseases and other cardiovascular diseases accounted for approximately half of all non-cancer CCD. SPN mortality accounted for 16.1% of CCD, with lung and bronchus cancer being the most prevalent. Stratification by the year of diagnosis revealed a drastic rise in CCD was observed in the last decade between 2005 and 2015, during which the SMR peaked. Advanced age, black race, small intestinal and gastric NETs, and cancer-directed surgery were significantly associated with an increased risk of CCD (p<0.001). Interestingly, female sex, pancreatic NETs, recto-anal NETs, NETs of unknown primary site, race other than white and black, distant and regional spread, chemotherapy and radiotherapy were significantly associated with a decrease in the incidence of CCD. Conclusions: CCD play an increasingly significant role in NET mortality in recent years, especially for those with higher risk of CCD. Further prospective studies are needed to evaluate the association of NETs with these CCD.