Understanding risk factors for low anterior resection syndrome in a South American cohort

Low Anterior Resection Syndrome (LARS) is a common postoperative bowel dysfunction in patients undergoing sphincter-preserving surgery for rectal cancer. Symptoms include fecal and gas incontinence, urgency, increased bowel frequency, and fragmented evacuations. LARS significantly impairs quality of life, affecting up to 90% of patients. Various factors contribute to its development, such as tumor height, extent of mesorectal excision, preoperative radiotherapy, and ileostomy. However, these factors are less studied in South American populations, where racial, cultural, and healthcare system differences may influence outcomes.

The aim of the study was to evaluate risk factors associated with LARS in a Chilean cohort of rectal cancer patients, with emphasis on cases classified as severe.

A non-concurrent prospective cohort study including patients who underwent low anterior resection between 2012 and 2021. Perioperative data collected included tumor height, surgical procedure type, preoperative radiotherapy, and protective ileostomy. Univariate and multivariate analyses were conducted to identify factors significantly associated with severe LARS, using the LARS score adapted to Chilean Spanish.

A total of 110 patients were included, with a median follow-up of 51 months. LARS was identified in 52.7% of cases, with 29.1% classified as major. Younger age, lower tumors, total mesorectal excision, preoperative radiotherapy, and ileostomy were significantly associated with severe LARS in univariate analysis. In multivariate analysis, only younger age and preoperative radiotherapy remained as independent risk factors.

In this Chilean cohort, nearly half of patients undergoing sphincterpreserving surgery for rectal cancer developed LARS. About one-third had the severe form, highlighting the need for targeted strategies to mitigate LARS and improve patient quality of life.