Assessment of long-term rectal function in patients who received pelvic radiotherapy: A pooled North Central Cancer Treatment Group trial analysis, N09C1

Purpose: Pelvic radiotherapy (PRT) is known to adversely affect bowel function (BF) and patient well-being. This study characterized long-term BF and evaluated quality of life (QOL) in patients receiving PRT. Methods: Data from 252 patients were compiled from two North Central Cancer Treatment Group prospective studies, which included assessment of BF and QOL by the BF questionnaire (BFQ) and Uniscale QOL at baseline and 12 and 24 months after completion of radiotherapy. BFQ scores (sum of symptoms), Uniscale results, adverse-event incidence, and baseline demographic data were compared via t test, χ ², Fisher exact, Wilcoxon, and correlation methodologies. Results: The total BFQ score was higher than baseline at 12 and 24 months (P < 0.001). More patients had five or more symptoms at 12 months (13 %) and 24 months (10 %) than at baseline (2 %). Symptoms occurring in greater than 20 % of patients at 12 and 24 months were clustering, stool-gas confusion, and urgency. Factors associated with worse BF were female sex, rectal or gynecologic primary tumors, prior anterior resection of the rectum, and 5-fluorouracil chemotherapy. Patients experiencing grade 2 or higher acute toxicity had worse 24-month BF (P values, <.001-.02). Uniscale QOL was not significantly different from baseline at 12 or 24 months, despite worse BFQ scores. Conclusions: PRT was associated with worse long-term BF. Worse BFQ score was not associated with poorer QOL. Further research to characterize the subset of patients at risk of significant decline in BF is warranted.