Gender differences in tumor characteristics, treatment allocation and survival in stage I-III pancreatic cancer: a nationwide study.

INTRODUCTION: Sex and gender are modulators of health and disease and may have impact on treatment allocation and survival in patients with cancer. In this study, we analyzed the impact of sex and gender on treatment allocation and overall survival in patients with stage I-III pancreatic cancer. METHODS: Patients with stage I-III pancreatic cancer diagnosed between 2015 and 2020 were selected from the nationwide Netherlands Cancer Registry. Associations between sex and gender and the probability of receiving surgical and/or systemic treatment were examined with multivariable logistic regression analyses. Overall survival was assessed with log rank test and multivariable Cox proportional hazard analysis. RESULTS: Among 6855 patients, 51.2 % were female. Multivariable logistic regression analyses with adjustment for known confounders (age, performance status, comorbidities, tumor location, tumor stage and previous malignancies) showed that females less often received systemic chemotherapy compared to males (OR 0.799, 95 %CI 0.703-0.909, p < .001). No difference was found in the probability for undergoing surgical resection. Furthermore, females had worse overall survival compared to males (median OS 8.5 and 9.2 months respectively, 95 %CI 8.669-9.731). CONCLUSION: This nationwide study found that female patients with stage I-III pancreatic cancer significantly less often received systemic treatment and had worse overall survival as compared to males. Disparities in pancreatic cancer care can be decreased by recognizing and resolving potential obstacles or biases in treatment decision-making.

Metachronous peritoneal metastases in patients with pT4b colon cancer: An international multicenter analysis of intraperitoneal versus retroperitoneal tumor invasion.

BACKGROUND: It was hypothesized that colon cancer with only retroperitoneal invasion is associated with a low risk of peritoneal dissemination. This study aimed to compare the risk of metachronous peritoneal metastases (mPM) between intraperitoneal and retroperitoneal invasion. METHODS: In this international, multicenter cohort study, patients with pT4bN0-2M0 colon cancer who underwent curative surgery were categorized as having intraperitoneal invasion (e.g. bladder, small bowel, stomach, omentum, liver, abdominal wall) or retroperitoneal invasion only (e.g. ureter, pancreas, psoas muscle, Gerota's fascia). Primary outcome was 5-year mPM cumulative rate, assessed by Kaplan-Meier analysis. RESULTS: Out of 907 patients with pT4N0-2M0 colon cancer, 198 had a documented pT4b category, comprising 170 patients with intraperitoneal invasion only, 12 with combined intra- and retroperitoneal invasion, and 16 patients with retroperitoneal invasion only. At baseline, only R1 resection rate significantly differed: 4/16 for retroperitoneal invasion only versus 8/172 for intra- +/- retroperitoneal invasion (p = 0.010). Overall, 22 patients developed mPM during a median follow-up of 45 months. Two patients with only retroperitoneal invasion developed mPM, both following R1 resection. The overall 5-year mPM cumulative rate was 13% for any intraperitoneal invasion and 14% for retroperitoneal invasion only (Log Rank, p = 0.878), which was 13% and 0%, respectively, in patients who had an R0 resection (Log Rank, p = 0.235). CONCLUSION: This study suggests that pT4b colon cancer patients with only retroperitoneal invasion who undergo an R0 resection have a negligible risk of mPM, but this is difficult to prove because of its rarity. This observation might have implications regarding individualized follow-up.