Gender Differences in Tumor Characteristics, Treatment and Survival of Colorectal Cancer: A Population-Based Study.

Background: The importance of sex and gender as modifiers of health and disease is increasingly recognized. The aim of this study was to analyze gender differences in incidence, tumor characteristics, treatment and relative survival (RS) in colorectal cancer (CRC).Methods: Observational population-based study including patients diagnosed with CRC in the Netherlands between 2010 and 2020. Stratified by localization (colon/rectum) and age (18-55/56-70/>71years), gender differences in incidence, tumor characteristics, treatment and RS were analyzed. Multivariable regression was used to analyze the influence of gender on treatment and RS.Results: The age-standardized incidence per 100,000 person-years of colon and rectal cancer is higher among men than women (colon: 41.2 versus 32.4, rectum: 22.8 versus 12.6). Besides differences in patient-and tumor characteristics, differences in treatment allocation and RS were observed. Most strikingly, women aged = 71 years with stage IV colon cancer are less often treated with systemic therapy (31.3 % versus 28.4 %, adjusted odds ratio (OR) 0.63, 95 % CI 0.48-0.83) and more often receive best supportive care only (47.6 % versus 40.0 %, adjusted OR 1.58, 95 % CI 1.19-2.11).Conclusion: Statistically significant and clinically relevant gender differences in incidence, patient-and tumor characteristics and treatment allocation are observed in patients with CRC. Reasons for differences in treatment allocation deserve further investigation.