Risk factors for Low Anterior Resection Syndrome (LARS) in patients undergoing laparoscopic surgery for rectal cancer

Background: Total mesorectal excision (TME) represents the "gold standard" of rectal cancer surgery. In locally advanced lesions neoadjuvant treatments (e.g. radiotherapy-nRT, radio chemotherapy-cnRT) have been shown to improve TME oncological results, reducing local recurrences rate. Nevertheless, these treatments have significant functional consequences impacting patients' quality of life (QoL). The resulting syndrome is known as Low Anterior Resection Syndrome (LARS). The purpose of this work was to evaluate the association between risk factors and the development of LARS in a prospective series of laparoscopic sphincter-saving TME. Methods: The study was conducted as a retrospective observational epidemiological study of a prospective database, including all patients undergoing laparoscopic anterior resection surgery for rectal cancer at our Unit from 1st January 2013 to 31st May 2018. The diagnosis of LARS was performed using the LARS Score. We classified risk factors in patient-related, pre-, intra- and post-operative factors. Results: The sample included 153 consecutive patients. Forty-one were affected by "low" rectal cancer, 74 by "middle" rectal cancer, 38 by "high" rectal cancer. The prevalence of overall LARS (major LARS + minor LARS) in our series was 35.9% (55/153 cases). Association between nRT and overall/major LARS was significant (respectively p = 0.03 and 0.02). Distal localization of tumor was also significantly associated with LARS [overall LARS (p = 0.03), major LARS (p = 0.014)]. Conclusions: In our study, neoadjuvant radiotherapy and tumor localization resulted independent risk factors for LARS after laparoscopic sphincter-saving TME. Tumor localization in the "middle" and "high" rectum resulted a protective factor compared to the localization in "low" rectum.