Effects of Neoadjuvant Chemio-Radiation Therapy on the Anal Sphincter Function in Patients with Low Rectal Cancers

The aim of the study was to compare functional results prior to and following neoadjuvant chemoradiation therapy.Materials and methods. An analysis of the functional results of a prospective clinical study was carried out. The study included 90 patients who underwent low anterior rectal resection for cancer of the lower or middle ampullar rectum with T1-4aN0-2M0 using various reconstruction methods.Results and discussion. Group A included 22 patients with J-shaped reservoirs; group B — 30 patients with side-to-end anastomoses; group C — 38 patients with end-to-end anastomoses. Out of the total study group (n = 90), 43 patients underwent neoadjuvant chemoradiotherapy vs. 47 patients without any preoperative treatment. No statistically significant difference was observed in the frequency of applied reconstructive techniques (р = 0.725) and the incidence of postoperative complications (p = 0.103) in the groups with and without neoadjuvant chemoradiotherapy. The baseline scores of the Wexner scale and the results of anorectal manometry in the comparison groups were comparable (p > 0.05). However, upon completion of neoadjuvant chemoradiotherapy and during the period from the moment of surgery up to 12 months after the closure of preventive intestinal stomas, the functional results were less satisfactory in the group of patients having received neoadjuvant chemoradiotherapy (n = 43) with regard to the comparison group (n = 47). Nevertheless, a statistically significant difference in the results was observed from the end of neoadjuvant chemoradiotherapy up to 3 months after closure of the stoma (p <0.05).Conclusions. Neoadjuvant chemoradiation therapy has a negative effect on the function of the anal sphincter, thus requiring concomitant therapy and physiotherapy both at the stages of neoadjuvant chemoradiotherapy and at long intervals after the main surgical stage