
1. Summary
1.1. Abstract
Rectal cancer is the third leading cancer in the world in terms of incidence and mortality according to GLOBOCCAN. The prognosis of the disease varies according to the stage, being better in the early stages and worse in the advanced and metastatic stages. Early diagnosis of colorectal cancer made through screening programs is accompanied by an improvement in the cancer progression. The introduction of colonoscopy examinations and testing for blood clots has made it possible to diagnose precancerous lesions and colorectal cancer in the early stages when the survival rate is better [1]. The treatment of colorectal cancer has evolved from just surgery before the 1980s to chemotherapy and radiotherapy in the 1980s and improving in later years with the introduction of new cytotoxic drugs that have improved survival. [2]. With advances in molecular biology methods, it is possible introduction as part of the treatment of new targeting and immunomodulatory drugs based on the results of these molecular tests.