Distant metastases are the main cause of death of patients with breast cancer. The substrate for the development of metastasis are the circulating tumor cells (CTCs). Determination of the expression of tumor-specific genes gives a more complete picture of the course of the tumor process.
Using PCR technology in real-time, gene expression studied BIRC5, Erb-b2/Her2-neu, ESR1, PGR1, MMP11, MDR1, MRP1, MXR at the CTCs in the surgical and adjuvant treatment of 56 cases primary non-metastatic breast cancer.
In 33 (59%) prior to surgery functionally active in the CTCs-enriched peripheral blood, samples expressing the targeted range of different genes have been found. Simultaneous expression of targeted genes detected in 15 (26.8%). The highest levels of expression of the genes identified for BIRC5 1.2013 ± 0.193965 (min – 0.0017; max – 10.7083) and-Erb-b2/Her2-neu 1.6886 ± 0.0939 (min – 0.1032; max – 17.4401). Expression of ESR1, PGR1 were determined in 23 patients (42.5%). Expression family of ABC transporters detected in 14 (25%). After the operation was observed decrease in the number of CTCs and including functionally active to 13 cases (23.2%), but the CTCs data determined high levels of gene expression BIRC5, c-Erb-b2/Her2-neu, and MXR. During adjuvant, treatment with anthracyclines observed decrease in the level of gene expression BIRC5, ESR1, PGR1 at the CTCs in 7 patients. However, in 6 samples marked increase in the level of gene expression MDR1, MRP1. In the course of a taxane therapy in combination with trastuzumab in a group of patients of the 14 people there was a decrease, and the complete disappearance of the expression of a-Erb-b2/Her2-neu in 9 people, but in 5 patients there was a significant increase in the level of expression of targeted genes-Erb-b2/Her2-neu, BIRC5 and MXR. Expression of the gene in MMR11 CTCs-positive samples was determined at a high level, but significant reduction in the course of chemotherapy has not been determined.
The data indicate a high diagnostic, prognostic and predictive value of determining the functional activity of the CTCs on the basis of determining the dynamics of gene expression of tumor progression at the stage of planning treatment of breast cancer.
Clinical trial identification
Legal entity responsible for the study
Educational Establishment “Vitebsk State Order of Peoples’ Friendship Medical University”
Belarusian Republican Foundation for Fundamental Research
All authors have declared no conflicts of interest.