[Meta-analysis comparing long-term outcomes of intersphincteric resection versus abdominoperineal resection for low...

Objective: To compare the long-term outcomes of intersphincteric (trans-internal and external) sphincter resection (ISR) and abdominoperineal proctocolectomy (APR) for low-grade rectal cancer. Methods: We used a meta-analytic approach to compare these procedures . Published reports comparing ISR and APR for low rectal cancer in Pubmed, Medline, EMBASE and Cochrane, China Knowledge Network (CNKI), China Biomedical Literature Database, and Vipers databases between January 2005 and January 2023 were searched and those meeting the eligibility criteria were selected for extraction of data for analysis. Inclusion criteria were as follows: (1) all reports comparing ISR and APR for low rectal cancer before January 2023; and (2) prospective randomized controlled studies or well-designed cohort studies. Exclusion criteria were as follows: (1) full text not available; (2) duplicate publications, missing primary outcome indicators, and unknown data; and (3) invalid statistical analysis. Results: Sixteen studies with 2498 patients were included in this study. Compared with the APR group, patients in the ISR group were relatively younger (weighted mean difference [WMD]=-1.82, 95%CI=-2.94 to -0.70, P=0.01), had tumors farther from the anal verge (WMD=0.43, 95%CI=0.18 to 0.67, P<0.01), and lower pathological T-stage (T3-4 stage: OR=0.54, 95%CI=0.36 to 0.81, P<0.01). In contrast, there were no statistically significant differences between the two groups in gender (P=0.78), body mass index (P=0.77), or pathological N stage (P=0.09). Compared with the APR group, patients in the ISR group had a lower rate of postoperative complications (OR=0.77, 95%CI=0.60 to 0.99, P=0.04), shorter hospital stay (WMD=-4.30, 95%CI=-7.07 to -1.53, P<0.01), higher 5-year overall survival (HR=0.54, 95%CI=0.33 to 0.88, P=0.01), and higher 5-year disease-free survival (HR=0.65, 95%CI=0.47 to 0.90, P<0.01). Five-year locoregional failure (HR=0.66, 95%CI=0.40 to 1.10, P=0.11) and time to surgery (WMD=-9.71, 95%CI=-41.89 to 22.47, P=0.55) did not differ significantly between the two groups. Conclusion: ISR is a safe and effective alternative to APR for early-stage low-grade rectal cancer.