Molecular genetic prognostic factors for metastatic regional lymph node involvement in breast cancer patients

Objective. To identify molecular genetic prognostic factors for metastatic regional lymph node involvement in breast cancer (BC) on the basis of the gene-expression prof iling analysis of primary tumors. Subjects and methods. The investigation enrolled 200patients with morphologically verified unicentric invasive BC (TjNo.M,) who had been treated at the Ulyanovsk Regional Clinical Oncology Dispensary in 2012 to 2015. A tumor tissue molecular genetic study was performed using reverse transcription-polymerase chain reaction (RT-PCR) assay; a diagnostic panel consisted of 28 functional genes. Results. In the metastatic regional lymph node involvement group, the primary breast tumor was characterized by enhanced proliferative activity in terms of the expression of the Ki-67 gene (p = 0.028) and by the higher mRNA levels of the NAT (p = 0.039) and CD68 (p <0.001) genes with a reduction in PTEN expression (p <0.001) and with decreased ESR1 gene expression (p = 0.043). A discriminant analysis showed that the accuracy in predicting the presence or absence of metastatic regional lymph node involvement on the basis of a primary tumor molecular genetic study using a 7-gene expression panel was 91.9 and 78.8%, respectively. Conclusion. The primary breast tumor tissue molecular genetic study involving a set of 7 genes (PTEN, CD68, CCNB1, MGB1, MYC, BCL2, and ESR1) can become an additional diagnostic tool for assessing the presence of metastatic lymph node involvement when planning the volume of axillary lymph node dissection in BC patients.

breast cancer, molecular genetic prognostic factors, gene expression profiling, mRNA, lymph node dissection, local recurrence, lymphogenous metastasis, discriminant analysis