DISSEMINATED TUMOR CELLS IN BLOOD AND BONE MARROW (MOLECULAR PROGNOSIS IN CLINICAL ONCOLOGY)

Osinsky S.P., Gluzman D.F.

The over all therapy outcome of malignant tumors remains unsatisfactory. Despite progress in surgical treat- ment and adjuvantsy stemic therapy, mortality is increasingly linked toearly metastases, which is of tenoc cultat the time of the primary diagnosis. Early hematogeneous dissemination of cancer cells is frequently responsible for the poor progno- sis after radical resection of solid tumors. Detection of occult disseminated tumor cells (DTC) is crucial to improve early diagnosis of metastases as well as therapy outcome. Recent advances in molecular biological techniques have made it possible to identify individual cancercells inbiological spec- imensand, inparticular, inperipheralblood(PB) andbone marrow(BM). DTC have been detected using the highlysensitive reverse transcriptase polymerase chain reaction (RT- PCR) technique and immunocytochemical (ICH) methods with monoclonal antibodies. The identification of DTC is based on the detection of expression of biomarkers that are specific for the tumor cells. Cancer cells have been detect- ed in PB and BM of patients staged by conventional diag- nostic technique as M0 in 28,3% and 33,1% cases, respec- tively. The sensitivity of detection with ICH and RT-PCR method samountstoaboutone cancer cell in 105-107 mono- nuclearcells. The prognostic relevance of disseminated cancer cells (DTC) has been demonstrated for some malignant tumors. Some problems remain: the optimization and stan- dardization of ICH and RT-PCR technology for the sensi- tive and specific recognition of cancer cells and the estimation of the clinical value of cancer cell detection in PB, BM and other biological specimens for diagnosis of early metas- tases and prognosis of clinical outcome.