Fine-needle aspiration biopsy possibilities in studying the molecular genetic landscape of breast tissue

Abstract

Background. Core biopsy of the breast is currently considered to be the standard method of obtaining material for morphological and molecular genetic methods. Unfortunately, this method is associated with a number of problems, primarily the risk of complications (bleeding, pneumothorax) and discomfort during manipulation.Aim. To analyze transcriptional signatures of breast tissue samples obtained by fine-needle aspiration biopsy. Materials and methods. Using reverse transcriptase polymerase chain reaction, we studied the mRNA expression level of 60 target genes in 60 samples obtained by fine-needle aspiration biopsy and in 60 corresponding formalin-fixed paraffin-embedded (FFPE) surgical specimens of breast. Samples were obtained from the tumor, adjacent tissue, the so-called tumor bed and formally normal tissue at a distance from the primary lesion.Results. A comparative analysis of transcriptional signatures in samples obtained by fine-needle aspiration biopsy and FFPE specimens (120 samples in total) reveled the strongest correlations between transcriptional signatures in biopsy samples and FFPE specimens of tumors. Very strong correlation in tumor samples was established for one gene (CTSL2); strong for 18 genes (MKI67, MYBL2, NAT1, PTEN, TPX2, PTTG1, UBE2T, CCNB1, ESR1, CCND1, MYC, SCGB2A2, MIA, TRAC, FGFR4, ANLN, GSTM1, PRLR); averages for 28 genes (PGR, AURCA, KRT5, FOXA1, SFRP1, EMSY, EXO1, PAK1, KIF14, ERBB2, MMP11, BCL2, BAG1, TMEM45B, BIRC5, CD274/PDL1, ZNF703, TYMS, CCNE1, TPT1, TMEM45A, BRCA1, BRCA2, ESR2, STS, TNFSF11/RANKL, TNFRSF11B/OPG, TNF); weak for 4 genes (GRB7, EGFR, PGRMC1, CYP19A). The presence of correlations between transcriptional signatures in biopsy samples and FFPE specimens can be established in case of sufficient material corresponding to sample intake control (SIC) ≥5 lg for B2M gene.Conclusion. The ability to conduct molecular genetic research on small samples of breast tissue makes it possible to obtain the material using the most minimally invasive method. And this, in turn, expands the possibilities of “genetic monitoring” of cancer, as well as the possibility of more accurate assessment the risks of malignant tumor development in the settings of benign conditions in women with fibrocystic disease and increased mammographic density.