The risk for rectal cancer recurrence and overall mortality is not increased in men previously diagnosed with prostate cancer: a report from the Swedish colorectal cancer registry.

Introduction: Limited data exists on oncological outcomes following rectal cancer surgery in men who have previously been diagnosed with prostate cancer (PC). This study aimed to assess overall mortality and rectal cancer recurrence in men previously diagnosed with PC who underwent bowel resection.

Methods: Data from the Swedish Colorectal Cancer Registry identified men who had rectal cancer surgery between 2000 and 2016, and the National Prostate Cancer Registry was used to identify those with a prior PC diagnosis. Cox regression analysis with propensity score matching was employed for data analysis. The primary outcome was overall mortality. Secondary outcome was recurrence for rectal cancer.

Results: Out of 13,299 men undergoing bowel resection for rectal cancer between 2000 and 2016, 1130 had a history of PC. Overall mortality did not significantly differ between men with and without a prior PC diagnosis. Cox regression analyses with propensity score matching revealed that men with previously diagnosed low- or intermediate-risk (HR, 0.79; 95% CI, 0.70-0.90) and high-risk PC (HR, 0.85; 95% CI, 0.74-0.98) had lower overall mortality after rectal cancer surgery compared with men without a PC. There was no significant difference in rectal cancer recurrence between men with a previous low or intermediate-risk PC (HR, 0.92; 95% CI, 0.74-1.14) or high-risk PC (HR, 0.73; 95% CI, 0.52-1.01) compared with those without PC history.

Conclusion: Men undergoing rectal cancer surgery with a previous diagnosis of prostate cancer do not experience an increased risk of rectal cancer recurrence or overall mortality compared with men without a previous history of prostate cancer.