PROGNOSTIC SIGNIFICANCE OF MONORESISTANCE GENE EXPRESSION IN TUMORS OF PATIENTS WITH NON-SMALL CELL LUNG CANCER AFTER PREOPERATIVE CHEMOTHERAPY

A significant role in the development of lung tumor resistance to drug therapy play so called mono resistance genes that determine resistance/sensitivity of tumor cells to distinct chemotherapeutic agents, they include BRCA1, RRM1, ERCC1, TOP1, TOP2a, TUBB3, TYMS, ABCC5 genes. It is shown that the use of these biomarkers as a criteria to appoint the adequate postoperative chemotherapy is associated with the forecast. However in the course of neoadjuvant chemotherapy change the expression profile of these genes can occur, which can lead to misinterpretation of results. In this regard perspective is the development of new relevant prognostic factors, which take into account occurred molecular genetic alterations in lung tumors after preoperative therapy. We presented the results of the combined treatment of 52 patients with NSCLC IIA - IIIB stage, based on the analysis of chemotherapy resistance/sensitivity gene expression for appointment the suitable drugs. It was found that the lack of expression of ERCC1 gene in lung tumor derived after neoadjuvant chemotherapy is associated with high rates of disease-free survival (P. = 0,00913). Low level expression of RRM1 gene (less than 0.5) is also associated with high rates of patient's survival (log-rank test P. = 0,01808), while a high level is a marker of poor prognosis. It is found that the combination of enhanced expression (>0.5) of any two or three genes: RRM1, ABCC5, TYMS, are the indicators of poor disease-free survival. We have shown that expression of ERCC1 gene is the independent prognostic factor. At zero ERCC1 expression in lung tumors, regardless of high or low level of expression of RRM1, ABCC5, TYMS genes, a high recurrence-free survival is observed. Thus, the data suggest the prognostic significance of the expression of ERCC1, TUBB3, RRM1, ABCC5 and TYMS genes in the lung tumor after neoadjuvant chemotherapy.