Endocrine Abstracts

Introduction/Background: Gender differences affect the treatment of several diseases in both male and female patients. However, the influence of gender on treatment decisions and outcome in neuroendocrine neoplasms (NENs) has scarcely been investigated.

Aims: Comparison of tumor characteristics, treatment decisions and outcome of patients with NENs, stratified by gender

Material and Methods: Retrospective analysis of the SwissNET cohort involving NENs of gastroenteropancreatic, pulmonal or unknown origin from 07/14 – 09/21. Site of origin, tumor grading, time to first treatment, choice of treatment and overall survival was assessed.

Results: 2329 patients were included in the analysis with 54% being male and 46% female patients. No significant difference in site of origin, tumor grading and staging was found between male and female patients. There was also no difference in time of symptoms onset until diagnosis and first treatment intervention. Surgery was performed in 66.3% of male and 71% of the female patients, P=0.016. Meanwhile, male patients received more often PRRT (22% vs 19.3%, P=0.007) and chemotherapy (15.9% vs 12.7%, P=0.032). Despite the similar tumor characteristics, the median overall survival of male patients was significantly lower compared to female patients (Male: 124.8 months, Female: 158.5 months, P<0.001). Interestingly, this difference was most pronounced in patients with lung NENs (Male: 142 months, Female: not reached) and cancer of unknown origin (Male: 18.5 months, Female: 35 months).

Conclusions: Male gender seems to be a risk factor for worse outcome, specifically for lung NENs and NENs of unknown origin. The underlying mechanisms of these findings remain to be established.