Nationwide analysis on sex differences in diagnosis, treatment and survival of rectal cancer

OBJECTIVE: Limited literature is available comparing sexes in rectal cancer. This nationwide study using real-world data was performed to evaluate sex-based differences in diagnosis, treatment and survival outcomes in rectal cancer. METHODS: Data from the Netherlands Cancer Registry were analyzed for patients diagnosed with rectal adenocarcinoma between 2015 and 2019. Patient and tumor characteristics, treatment strategies, response to neoadjuvant therapy, and survival outcomes were compared between sexes. RESULTS: The cohort consisted of 22251 patients (37.1% women, 62.9% men). Women more frequently presented with cT4 tumors (16% vs. 11%, P < 0.001) but no differences were observed in nodal status, distant metastases, use of neoadjuvant (chemo) radiotherapy and radicality in resections between sexes. In the total study population, 5-year survival did not differ significantly (63.6% in women vs. 61.6% in men, P=0.23). However, in surgically treated patients, survival was higher in women (77.4% vs. 75.0%, P=0.019). Female sex was an independent predictor for survival in surgically treated patients (HR 0.90; 95% CI 0.82-0.98). In the subgroup of patients who were asymptomatic at the time of diagnosis [n=1320], there were no sex-based differences in presentation, treatment, or survival (5-year overall survival: 78.8% vs. 80.4%, P=0.45). CONCLUSION: Sex-based differences exist in rectal cancer presentation and outcome. Women are more likely to present a more advanced T-stage. Despite this, women have a better overall survival after surgical treatment. In contrast, men and women undergoing treatment for asymptomatic rectal cancer have comparable outcomes.