LAUSR

Simple Summary We conducted a retrospective, population-based study comparing overall survival (OS) between males and females with neuroendocrine neoplasia (NEN). In total, 14,834 cases of NEN recorded in England’s National Cancer Registry and Analysis Service (NCRAS)), were analysed. Multivariable analysis, restricted mean survival time and mediation analysis were performed. Females displayed increased survival irrespective of the stage, morphology or level of deprivation, which was statistically significant in NEN of the lung, pancreas, rectum and stomach (p < 0.001). Stage of tumour mediated improved survival in stomach, lung, and pancreatic NEN but not in rectal NEN. Females diagnosed with NEN tend to survive longer than males, and stage at presentation only accounts for part of this effect. Future research in NEN, as well as prognostication and treatment, should consider sex as an important factor. Abstract Pre-clinical studies have suggested sex hormone signalling pathways may influence tumorigenesis in neuroendocrine neoplasia (NEN). We conducted a retrospective, population-based study to compare overall survival (OS) between males and females with NEN. A total of 14,834 cases of NEN diagnosed between 2012 and 2018, recorded in England’s National Cancer Registry and Analysis Service (NCRAS), were analysed. The primary outcome was OS with 5 years maximum follow-up. Multivariable analysis, restricted mean survival time and mediation analysis were performed. Appendiceal, pulmonary and early-stage NEN were most commonly diagnosed in females; stomach, pancreatic, small intestinal, colonic, rectal and later-stage NEN were more often diagnosed in males. Females displayed increased survival irrespective of the stage, morphology or level of deprivation. On average, they survived 3.62 (95% CI 1.73–5.90) to 10.26 (6.6–14.45) months longer than males; this was statistically significant in NEN of the lung, pancreas, rectum and stomach (p < 0.001). The stage mediated improved survival in stomach, lung, and pancreatic NEN but not in rectal NEN. The reasons underlying these differences are not yet understood. Overall, females diagnosed with NEN tend to survive longer than males, and the stage at presentation only partially explains this. Future research, as well as prognostication and treatment, should consider sex as an important factor.