Molecular diagnosis of cancer in the large regional oncology center: possibilities and limitations for use in clinical oncology

Aim. To summarize the results of 19-year activity in laboratory of immunohistochemical tumor diagnosis of Tatarstan Regional Cancer Centre of Ministry of Health, Republic of Tatarstan.

Methods. Advantages and limitations of modern molecular techniques for the diagnosis of human tumors are discussed based on our own experience and the literature data.

Results. A number of tumor cells molecular targets (e.g., growth factor receptors, differentiation antigens) are being determined in Tatarstan Regional Cancer Centre since 1996 on the daily basis for creating a «molecular portrait of tumor» and customized therapy adjustment. The total number of tumors investigated using immunohistochemistry, systematically increased from 150 in 1996 to 5910 in 2014, and for each tumor 1 to 12 (usually 4-5) or more antigens expression is evaluated. Since 2007, molecular cytogenetic studies of potential targets for the treatment of breast cancer, stomach and lung are investigated. To identify HER2 oncogene amplification performed 894 assays were performed in 2007-2011 using chromogenic in situ hybridization and 1064 assays using fluorescence in situ hybridization were performed in 2011-2014. Since November 2014 we are using fluorescence in situ hybridization to detect ALK-EML4 translocation in lung adenocarcinomas, during the last month of the 2014 38 tests were performed. For two decades, the laboratory, which has a reference status in the Volga region of Russian Federation, has verified the diagnosis in 32 thousand patients, among them 55% cases of breast cancer (prognostic markers), 18% - lymphoproliferative processes, 15% - anaplastic tumors and metastatic cancers of unknown primary source, 12% were soft tissue tumors. Error rate for immunohistochemical diagnosis was 2.6%, mainly involving central nervous system tumors, lymphomas, and metastatic cancers of unknown primary source.

Conclusion. Modern morphological tumor verification provides high quality diagnosis and treatment of cancer patients in the Republic of Tatarstan for many years.