PECULIARITIES OF THE DISTRIBUTION AND DYNAMICS OF EXPRESSION OF APOPTOSIS MARKER Bax IN PACTIENTS WITH RECTAL CANCER UNDER THE INFLUENCE OF NEOADJUVANT CHEMORADIOTHERAPY WITH THE USAGE OF NITRIC OXIDE PRECURSOR

The aim of research is to determine the peculiarities of proapoptotic Bax protein expression in the intact intestine and tumor of patients with rectal cancer under the influence of neoadjuvant chemoradiotherapy (NCRT) using polyradiomodification with ftorafur and tivortine. Bax expression was determined by immunohistochemistry in biopsy and surgical material before and after NCRT in 21 patients with adenocarcinoma of the rectum stage II-III. It has been established that under the influence of NCRT the level of Bax expression in the intact rectum increases slightly. However, expression of Bax in residual tumor parenchyma has increased greatly compared with thаt before treatment, especially after polyradiomodification, thus correlating with the degree of therapeutic pathomorphosis. This indicates the importance of the apoptosis as a mechanism of NCRT antineoplastic action, as well as the feasibility of the polyradiomodification with the usage of nitric oxide precursor.