Background: The molecular classification of breast cancer mainly focuses on estrogen receptor (ER), Progesterone receptor (PgR), and Human Epidermal Growth Factor Receptor 2(HER2/Neu) status detected by immunohistochemistry (IHC) analysis. The β -tubulin isotype III (TUBB3) gene was thought to be a marker of taxane resistance or cancer aggressiveness.
Methods: To evaluate the clinicopathological significance of TUBB3 expression in breast cancer patients, we measured TUBB3 mRNA levels in 92 breast cancer patients by Quantitative reverse transcription-polymerase chain reaction (qRT-PCR), and examined their correlation with ER, PgR, and HER2 status detected by IHC.
Results: We observed a significant positive correlation between the TUBB3 mRNA expression and the immunohistochemical positivity of both PgR (p= 0.000) and HER2 (p= 0.001). In addition, TUBB3 mRNA expression was associated with lymph nodes status (P= 0.008) and tumor stages (0.029), but no correlation was found with other clinicopathological features, such as age, pathohistological grades and tumor size.
Conclusions: In conclusion, TUBB3 expression correlated significantly with molecular markers of breast cancer, such as PgR and HER2, suggesting that TUBB3 mRNA level facilitate the identification of a subset of patients who respond to Taxane treatment in addition to hormonal therapy and trastuzumab.
Keywords: Breast cancer; ER; HER2; PgR; β -tubulin isotype III.