Prediction of anorectal dysfunction in the combined treatment of rectal cancer

AIM: to assess the risk of severe low anterior resection syndrome (LARS) in patients with rectal cancer after combined treatment. PATIENTS AND METHODS: from July 2022 to November 2023, 50 patients with rectal cancer underwent radiation with a total focal dose of 50–54 Gy with radiomodification with capecitabine and low anterior rectal resection with preventive ileostomy. The ileostomy was closed after 4 months. Prior to and after radiation, the anorectal function was assessed using high-resolution anorectal manometry (HRAM) and the LARS scale. RESULTS: the most significant predicting factors for severe LARS were maximal contraction pressure and first sensation volume. Three months after ileostomy closure, the patients were divided into groups depending on the HRAM parameters. Group 1: nine patients with severe LARS (34 points on the LARS scale), with a decrease in maximal contraction pressure by ≥ 30% and an increased first sensation volume by ≥ 60%, according to HRAM. Group 2: four patients out of 36 had severe LARS (31 points on the LARS scale), with a decrease in maximal contraction pressure by 5–29% and an increased first sensation volume by 10–59%, according to HRAM. Group 3: in 5 patients with a decreased maximal contraction pressure by ≤ 4% and an increased volume of the first sensation by ≤ 9%, LARS did not develop. CONCLUSION: a decrease in the maximal contraction pressure by 30% or more and an increase in the volume of the first sensation by 60% or more after radiation therapy can increase the risk of severe LARS. This group of patients requires prevention and correction of anorectal dysfunction.