Analysis of Rectal Neoplasms Operated After Neoadjuvant Therapy in A Period of 10 Years

Background: With the advances of neoadjuvant chemoradiotherapy, the identification of complete tumor responses, and the reduction of local recurrence even with the adoption of expectant approaches aimed at sphincter preservation, several authors have published results analyzing these aspects with conflicting results, which require further investigation. Objectives: This study aims to evaluate the anatomopathological changes in surgical specimens of rectal resection due to adenocarcinoma in patients undergoing neoadjuvant therapy, including the complete response rate, in addition to estimating the sensitivity and specificity indexes of the imaging methods used in the preoperative period. Methods: This was an observational, retrospective, cross-sectional study in which 44 medical records of patients with cancer of the middle and lower rectum who underwent neoadjuvant chemoradiotherapy and subsequently underwent oncological surgical resections over 10 years were studied. Demographic data, CT scans, colonoscopies, anatomopathological reports and surgical reports were analyzed. Results: Abdominoperineal resection of the rectum (APR) was performed in 16 cases (36.4%), and abdominal rectosigmoidectomy (AR) was performed in 28 cases (63.6%). Preoperative computerized tomography (CT) showed a sensitivity of 75% and specificity of 77.8% for the detection of lymph node metastases. The complete pathological response to neoadjuvant chemoradiotherapy was found in 11.36% of cases. The local recurrence was detected in 23.9% cases and distant metastasis in 15.2% of the patients on the follow-up period, additionally, there was a 77.7% 5-years disease-free survival and the overall survival was 73.9%. Conclusions: The rate of complete pathological response to neoadjuvant therapy was 11.36%. Locally advanced disease and angiolymphatic embolization were associated with a higher frequency of lymph node involvement. CT obtained high rates of sensitivity and specificity for comparison with anatomopathological results.