In recent decades, oncological diseases have become one of the most important causes of death in people around the world; the annual number of deaths from cancer exceeds half of the number of newly diagnosed cases of the disease. The determination of biomarkers can provide information on the clinical course of the malignant process and predict the chemoresistance of a neoplasm in an individual patient. However, the identification of markers for a more accurate prognosis of the course of the disease and the choice of adequate therapy is still an unsolved problem [1,2]. Therefore, the study of the pathological mechanisms underlying the development of oncological diseases, the elucidation of their molecular markers for early diagnosis and effective treatment, still remain an urgent problem.

Oncological diseases, biomarkers, effectiveness of therapy

1.Vineis P.Perera. F. Molecular epidemiology and biomarkers in etiologic cancer research // Cancer Epidemiol. Biomarkers. -2007. V. _ 16.P. _ _ 1954–1965.

Semiglazov V.F., Semiglazov V.V., Dashyan G., Bessonov A. Tumor markers in breast cancer // Doctor. - 2011. No. 12.- P.2-7 .

Allen JD, Schinkel AH Multidrug resistance and pharmacological protection mediated by the breast cancer resistance protein //Mol Cancer Ther. - 2002. - V. 1, N 6. - P. 427-434.

Atalay C., Deliloglu Gurhan I., Irkkan C., Gunduz U. Multidrug resistance in locally advanced breast cancer // Tumour Biol. - 2006. - V. 27, N 6. - P. 309-318.

Allen JD, Brinkhuis RF, van Deemter L., Wijnholds J., Schinkel AH Extensive contribution of the multidrug transporters P-glycoprotein and MRP1 to basal drug resistance // Cancer Research. - 2000. - V. 60, N 20. - P. 5761-5766.

Ambudkar SV, Kimchi-Sarfaty C., Sauna ZE, Gottesman MM P-glycoprotein: from genomics to mechanism // Oncogene. - 2003. - V. 22, N 47. - P. 7468-7485.

Vlassov VV, Laktionov PP, Rykova EY Extracellular nucleic acids // Bioessays.- 2007.- V. 29.- P . 654–667.

8 . Rykova E.Yu., Skvortsova T.E., Hoffman A.L. Circulating extracellular DNA and RNA of blood in the diagnosis of breast tumors. // Biomed. chemistry. -2008. - T. 54. - No. 1. - P. 94-103.

9 . Rengarajan L, Cristol SM, Mehta M, Nickerson JM: Quantifying DNA concentrations using fluorometry: a comparison of flourophores// Mol Vis.- 2002.- 8.- R. 416-421.

10 . Zemlyakova V.V., Zhevlova A.I., Strelnikov V.V. and others. Abnormal methylation of some suppressor genes in sporadic breast cancer.// – 2003 – Mol. biol. T . 37 – S. 693-703.

eleven . Chan AO, Kim SG, Bedeir A. CpG island methylation in carcinoid and pancreatic endocrine tumors// Oncogene. – 2003. – V. 13. – P. 924-934.

12 . Tserga A., Michalopoulos NV, Levidou G. Association of aberrant DNA methylation with clinical pathological features in breast cancer//Oncol. Rep. -2012. -V. 27. No. 5.- R. 1630–1638.