Low anterior resection syndrome after radical surgical treatment of rectal cancer: interim results of a multicenter interuniversity clinical trial

Introduction. Low anterior resection syndrome (LARS) is a socially significant problem in oncology and coloproctology, leading to disability and a decrease in the quality of life in up to 80 % of patients after anterior rectal resection (ARR) with total mesorectumectomy (TME). Many methods have been developed to prevent and treat LARS, but the results have remained unsatisfactory in practice. The objective of the study was to assess the incidence, severity, contribution of neoadjuvant therapy and other risk factors in the development of LARS after ARR with TME in patients with cancer. Methods and materials. A multicenter, retrospective, cohort clinical trial was conducted. 7 medical and preventive institutions in the Russian Federation took part in the study. The study included patients with tumors of the middle and lower ampulla rectum who underwent radical surgical treatment including ARR with TME. The patients were divided into 2 groups: a group of patients who underwent neoadjuvant treatment and a group of patients who did not underwent neoadjuvant treatment. Telephone questionnaires and medical record analysis (paper or electronic) was conducted in both groups. Primary endpoints: the incidence of LARS after ARR with TME, depending on the presence of a neoadjuvant stage of treatment. Secondary endpoints: the frequency of occurrence and severity of LARS depending on risk factors (RF). The first step of the study: the telephone questionnaire using the LARS score questionnaire, an verbal assessment of the RF: the presence of preventive stoma, neoadjuvant and adjuvant therapy. The second step: analysis of medical documentation in order to assess the RF: type of anastomosis, surgical access, postoperative complications, lymph node dissection volume, use of intraoperative neuromonitoring, duration of surgery, timeframe of the reconstructive step, mode and timing of drug or combined treatment. Depending on the type of data and the distribution of values, the methods of parametric and nonparametric statistics was used. Regression analysis methods was used to assess the contribution of the RF to the LARS. Intergroup differences are considered statistically significant when p<0.05. Data analysis was conducted using the SPSS 19.0 software package. Results. Data from 104 patients who met the inclusion criteria for the study were analyzed: 83 patients (79.8 %) with neoadjuvant treatment and 21 patients (20.2 %) without it. The groups were comparable to each other in terms of gender, age, tumor location, cT-criterion and pathomorphological characteristics of the tumor. In both groups, LARS occurred in 66 patients (63 %), with 39 people (37 %) having pronounced LARS. A statistically significant difference was found in the incidence of LARS between the groups: in the group with neoadjuvant treatment, LARS was detected in 58 patients (70 %), in the group without preoperative treatment in 8 patients (38 %), Mann–Whitney 594.5, p = 0.007. There is also a statistically significant difference in the incidence of pronounced LARS between the groups: in the group with neoadjuvant treatment in 35 patients (42 %), in the group without preoperative treatment in 4 patients (19 %), Pearson Chi-square: 7.302, p = 0.038. A statistically significant correlation was found between the presence of LARS and the volume of lymph dissection, the Pearson Chi-squared conjugacy coefficient = 8.152, p=0.004, and the V-Kramer value 0.280 (average correlation). Conclusion. LARS is a common complication after ARR with TME, occurring in 63 % of patients even 78 months after the initial surgery. After the neoadjuvant stage of treatment, LARS occurs statistically significantly more often. > <0.05. Data analysis was conducted using the SPSS 19.0 software package. Results. Data from 104 patients who met the inclusion criteria for the study were analyzed: 83 patients (79.8 %) with neoadjuvant treatment and 21 patients (20.2 %) without it. The groups were comparable to each other in terms of gender, age, tumor location, cT-criterion and pathomorphological characteristics of the tumor. In both groups, LARS occurred in 66 patients (63 %), with 39 people (37 %) having pronounced LARS. A statistically significant difference was found in the incidence of LARS between the groups: in the group with neoadjuvant treatment, LARS was detected in 58 patients (70 %), in the group without preoperative treatment in 8 patients (38 %), Mann–Whitney 594.5, p = 0.007. There is also a statistically significant difference in the incidence of pronounced LARS between the groups: in the group with neoadjuvant treatment in 35 patients (42 %), in the group without preoperative treatment in 4 patients (19 %), Pearson Chi-square: 7.302, p = 0.038. A statistically significant correlation was found between the presence of LARS and the volume of lymph dissection, the Pearson Chi-squared conjugacy coefficient = 8.152, p=0.004, and the V-Kramer value 0.280 (average correlation). Conclusion. LARS is a common complication after ARR with TME, occurring in 63 % of patients even 78 months after the initial surgery. After the neoadjuvant stage of treatment, LARS occurs statistically significantly more often.