203P - Comparative Evaluation of Receptor Status of Primary Tumor Cells, Metastasis, Recurrence and Circulating Cancer Cells in Breast Cancer Patients

Abstract

ABSTRACT Aim: To study the influence of phenotypic heterogeneity of a primary tumor, metastases and circulating tumor cells at different stages of tumor progression as a cause of therapeutic resistance in breast cancer patients. Methods: The study involved 120 patients with operable breast cancer with the stage T1-4N0-3M0-1 at the age of 32-80 years (average age–59.49 ± 1.08 years). The patients were divided into 3 groups according to the staging of the disease: 1) the I group -TI-4N1-2M0 (breast tumor + metastasis in one or more regional lymph nodes) 2) theII group -T recM0-1 (recurrences or distant metastases in breast cancer patients) 3)the III group -T recM0-1 (i+), (circulating cancer cells in the blood of breast cancer patients) The tissue samples taken from 93 patients (60 persons of the I group and 33 persons of the II group) were test material in the I and II group. 120-150 ml of venous blood taken from 27 patients was test material in the III group. Results: 1) The objective reductionof estrogen(14.7% (p 2) The objective increase in Her/2neu expression level (59.8%(p 3) The immunophenotypeof CTCs in 52% (p Conclusions: 1) As the disease progresses in the foci of breast cancer metastases and recurrences, the level of estrogen and progesterone receptor expression is reduced and Her/2neu expression level is increased. 2) In most cases the immunophenotypeof CTCs does not correspond to the immunohistochemistry status of a primary tumor. 3) In order to customize the treatment it is appropriate to determine the receptor status of cells in each focus of recurrence or metastasis, as well as the one of CTCs. Disclosure: All authors have declared no conflicts of interest.