The role of modern neoadjuvant radiotherapy in the combined treatment of locally advanced rectal cancer

Currently, rectal cancer is one of the leading pathologies in the structure of cancer morbidity and mortality, both in Russia and around the world. Thus, despite the improvement of existing and development of new methods for surgical treatment and anesthesia, as well as the introduction of the use of radio-and chemotherapy as an adjunct to surgical stage of the treatment, colorectal cancer still has a very high mortality rate among this cohort of cancer patients, and, primarily, due to the fact that approximately 30% of cases it is diagnosed at a very late stages of the disease. And, at the same time, combined and complex therapy to date does not contribute to improving the long-term results of special treatment, which, in the end, range from a complete response, in particular, during radiotherapy treatment, up to absolute resistance to its implementation. However, to date, there are already studies confirming the link between radioresistance and gene expression, which induce a response to the DNA damage checkpoint and increase the ability to repair DNA. At the same time, molecular biomarkers have a definite potential to predict the response to, in particular, neoadjuvant chemoradiotherapy for rectal cancer. This brief review examines the evolution and current state of neoadjuvant (preoperative) chemoradiotherapy for locally advanced rectal cancer (MRPC). At the same time, it should be emphasized that randomized studies and meta-analyses of recent publications justify the expediency of its use in this category of cancer patients.  Modern strategies for treating patients with locally advanced rectal cancer and radiotherapy regimens used in this clinical situation are also briefly considered, as well as the prospects for using molecular genetic markers of radiosensitivity and their possible impact on the prognosis of this cancer.