Association of gene expression with lymph node breast cancer metastasis

The most serious complication of breast cancer (BC), which affects life expectancy, is metastasis of the tumor. Metastasis is the cause of more than 80% of all breast cancer deaths. After surgical treatment and the use of adjuvant therapy, metastases occur in 8% – 15% of cases. This indicates the need to develop markers for the prognosis of metastasis and clarify its mechanisms for the creation of anti-metastatic therapeutic agents. In this paper, we studied the association of LOX and uPAR gene expression with breast cancer metastasis in the lymph nodes.

Gene expression was measured using real-time PCR in 40 paired samples (tumor-normal tissues). As a result of processing the measurements, the values of gene expression levels in the tumor tissue relative to normal were obtained.

It is shown that the LOX gene is expressed in the tumor both lower and higher relative to the norm, and uPAR is expressed in most cases higher. In metastatic tumors, the frequency of expression increases above the norm for both LOX and uPAR genes. The association of expression of these genes with lymphatic metastasis was found: p = 0.01 and p = 0.02, for the LOX and uPAR genes, respectively. The relative risk (RR) was for the LOX gene RR = 1.9, 95% CI 1.2 – 3, p = 0.005, for uPAR RR = 3.6, 95% CI 1.2 – 10.9, p = 0.03.

Thus, the data obtained contribute to understanding the mechanisms of metastasis and provide the basis for the development of new biomarkers. The LOX and uPAR genes may be candidates for predictive markers of breast cancer metastasis risk.