Bowel Dysfunction After Low Anterior Resection With Neoadjuvant Chemoradiotherapy or Chemotherapy Alone for Rectal Cancer: A Cross-Sectional Study from China

BACKGROUND:Neoadjuvant therapy plays a vital role in the treatment of locally advanced rectal cancer but impairs bowel function after restorative surgery. Optimal decision making requires adequate information of functional outcomes. OBJECTIVE:This study aimed to assess postoperative bowel function and to identify predictors for severe dysfunction. DESIGN:The study included a cross-sectional cohort and retrospective assessments of pelvic anatomic features. SETTINGS:The study was conducted at a tertiary GI hospital in China. PATIENTS:Included patients underwent neoadjuvant chemoradiotherapy or chemotherapy without radiation and curative low anterior resection for rectal cancer between 2012 and 2014. MAIN OUTCOME MEASURES:Bowel function was assessed using the validated low anterior resection syndrome score. The thicknesses of the rectal wall, obturator internus, and levator ani were measured by preoperative MRI. RESULTS:A total of 151 eligible patients were identified, and 142 patients (94.0%) participated after a median of 19 months from surgery. Bowel dysfunction was observed in 71.1% (101/142) of patients, with 44.4% (63/142) reporting severe dysfunction. Symptoms of urgency and clustering were found to be major disturbances. Regression analysis identified preoperative long-course radiotherapy (p < 0.001) and a lower-third tumor (p = 0.002) independently associated with severe bowel dysfunction. Irradiated patients with a lower-third tumor (OR = 14.06; p < 0.001) or thickening of the rectal wall (OR = 11.09; p < 0.001) had a markedly increased risk of developing severe dysfunction. LIMITATIONS:The study was based on a limited cohort of patients and moderate follow-up after the primary surgery. CONCLUSIONS:Bowel function deteriorates frequently after low anterior resection for rectal cancer. Severe bowel dysfunction is significantly associated with preoperative long-course radiotherapy and a lower-third tumor, and the thickening of rectal wall after radiation is a strong predictor. Treatment decisions and patient consent should be implemented with raising awareness of bowel symptom burdens. See Video Abstract at http://links.lww.com/DCR/A317.