[Cross-sectional study of low anterior resection syndrome in patients who have survived more than 5 years after sphincter-preserving surgery for rectal cancer].

Objective: In this study, we aimed to investigate the prevalence of low anterior resection syndrome (LARS) in patients who had survived for more than 5 years after sphincter-preserving surgery for rectal cancer and to analyze its relationship with postoperative time. Methods: This was a single-center, retrospective, cross-sectional study. The study cohort comprised patients who had survived for at least 5 years (60 months) after undergoing sphincter- preserving radical resection of pathologically diagnosed rectal adenocarcinoma within 15 cm of the anal verge in the Department of Gastrointestinal Surgery, Peking University People's Hospital from January 2005 to May 2016. Patients who had undergone local resection, had permanent stomas, recurrent intestinal infection, local recurrence, history of previous anorectal surgery, or long- term preoperative defecation disorders were excluded. A LARS questionnaire was administered by telephone interview, points being allocated for incontinence for flatus (0-7 points), incontinence for liquid stools (0-3 points), frequency of bowel movements (0-5 points), clustering of stools (0-11 points), and urgency (0-16 points). The patients were allocated to three groups based on these scores: no LARS (0-20 points), minor LARS (21-29 points), and major LARS (30-42 points). The prevalence of LARS and major LARS in patients who had survived more than 5 years after surgery, correlation between postoperative time and LARS score, and whether postoperative time was a risk factor for major LARS and LARS symptoms were analyzed. Results: The median follow-up time of the 160 patients who completed the telephone interview was 97 (60-193) months; 81 (50.6%) of them had LARS, comprising 34 (21.3%) with minor LARS and 47 (29.4%) with major LARS. Spearman correlation analysis showed no significant correlation between LARS score and postoperative time (correlation coefficient α=-0.016, P =0.832). Multivariate analysis identified anastomotic height (RR=0.850, P =0.022) and radiotherapy (RR=5.760, P <0.001) as independent risk factors for major LARS; whereas the postoperative time was not a significant risk factor (RR=1.003, P =0.598). The postoperative time was also not associated with LARS score rank and frequency of bowel movements, clustering, or urgency ( P >0.05). However, the rates of incontinence for flatus (3/31, P =0.003) and incontinence for liquid stools (8/31, P =0.005) were lower in patients who had survived more than 10 years after surgery. Conclusions: Patients with rectal cancer who have survived more than 5 years after sphincter-preserving surgery still have a high prevalence of LARS. We found no evidence of major LARS symptoms resolving over time.