Long-term anorectal function in rectal cancer patients treated with chemoradiotherapy and endorectal brachytherapy.

Abstract

The aim was to study anorectal function in long-term survivors after combined, curatively intended, chemoradiotherapy and endorectal brachytherapy for low rectal cancer. This was a case-control design. We compared anorectal function by anal manometry, anal functional lumen imaging probe (EndoFLIP) and rectal bag distension in rectal cancer patients (RCPs) and healthy, normal subjects (NSs). Symptoms were assessed by the low anterior resection syndrome (LARS) and Wexner faecal incontinence scores. Thirteen RCPs (12 men, median age 68years, range 52-92) after 60Gy radiotherapy, 5Gy endorectal brachytherapy and oral tegafur-uracil with complete clinical response (median time since treatment 2.8years, range 2.2-5.6) were compared to 15 NSs (14 men, median age 64years, range 47-75). RCPs had lower than normal anal resting pressure, 38.6 mmHg (range 8.8-67.7) versus 58.8mmHg (25.7-105.2) (P<0.003), and squeeze pressure, 117 mmHg (55.2-203) versus 188mmHg (103-248) (P<0.01). Squeeze-induced pressure increase recorded by EndoFLIP was also lower in RCPs (q>7.56, P<0.001) as was the anal canal resistance to increasing distension (q=3.13, P<0.05). No differences in median rectal volume at first sensation (72 [22-158] vs. 82 [36-190] ml, P=0.4) or at urge to defaecate (107 [42-227] vs. 132 [59-334] ml, P=0.2) were found. However, maximum tolerable rectal volume was lower in RCPs (145 [59-319] vs. 222 [106-447] ml, P<0.02). The median (range) low anterior resection syndrome score was 27 (0-39) for RCPs and 7 (0-23) for NSs (P<0.001), while the Wexner score was 0 (0-5) versus 0 (0-4) (P=0.56). Radiotherapy combined with endorectal brachytherapy for rectal cancer causes long-term anorectal symptoms, impaired anal sphincter function and reduced rectal capacity.