Trends and outcomes of sphincter-preserving surgery for rectal cancer: a national cancer database study

Purpose: Previous studies have shown that sphincter-preserving surgery is associated with better quality of life in postsurgical rectal cancer patients. However, the factors predicting the likelihood of undergoing sphincter-preserving surgery have not been well-described. The aim of this study was to report the factors that determined the likelihood of undergoing sphincter-preserving surgery. Methods: Characteristics of 24,018 rectal cancer patients undergoing sphincter-preserving surgery and abdominoperineal resection diagnosed from 2008 to 2012 from the National Cancer Database were investigated retrospectively for rate, pattern, and differences in mortality. Cox proportional hazards models were used to calculate hazard ratios for assessing mortality. Odds ratios were calculated using logistic regressions models for outcome sphincter-preserving surgery. Results: Eighteen thousand four hundred fifty-two (77%) patients had sphincter-preserving surgery. Majority of sphincter-preserving surgery patients were aged < 70 (74%), had private insurance (52%), and got treatment at a comprehensive community cancer program (54%). Multivariable analysis showed that patients with age ≥ 70 (OR 0.87, 95% CI 0.80–0.95), male gender (OR 0.90, 95% CI 0.84–0.96), having Medicare (OR 0.83, 95% CI 0.76–0.90), Medicaid (OR 0.72, 95% CI 0.63–0.81), and poorly differentiated grade (OR 0.78, 95% CI 0.71–0.85) were less likely to undergo sphincter-preserving surgery. Multivariable analysis showed that patients having abdominoperineal resection have higher likelihood of mortality than sphincter-preserving surgery (HR 1.26, 95% CI 1.16–1.36). Conclusions: We were able to identify several patient and tumor-related factors impacting the likelihood of undergoing sphincter-preserving surgery. Patients undergoing non-sphincter sparing surgery had a higher mortality that sphincter preservation.