Evaluation of the relationship between histologic response of the primary tumor and the nodal status after neoadjuvant therapy for rectal cancer

Abstract

Colorectal cancer is the third most common malignant neoplasia in the world and the fourth most common cancer in Iran. Several risk factors including genetics, age, smoking, and diet play a role in developing rectal cancer. The standard treatment for rectal cancer patients with locally advanced cases (stage II, III) is surgery by APR or LAR method, pre-operative (neo-adjuvant treatment) or post-operative (adjuvant treatment) chemoradiotherapy, where neo-adjuvant treatment is preferred because of Better Functional outcome, better patient tolerance and better pathological response. Neoadjuvant chemoradiotherapy may change the pathological T stage and N stage by reducing the depth of tumor invasion, causing complete destruction of the malignant cells of the rectal wall and perirectal lymph nodes. Therefore, the present study was conducted with the aim of investigating the relationship between tissue response of primary tumor and lymph node status after neoadjuvant treatment in rectal cancer, so that the research results will be available to Iranian researchers and doctors.

Materials and methods: The present study is an analytical cross-sectional study. In this study, the data obtained from the documents of patients with rectal cancer who were admitted from April 15, 2017 to April 15, 2019. then in the patients eligible for the study, the data related to age, gender, The total dose of radiotherapy, drugs used in chemotherapy, tumor differentiation, lymphovascular invasion and perineural invasion and TNM staging before and after neoadjuvant treatment were statistically analyzed using SPSS software.