TOPK: A new predictor of the therapeutic response to neoadjuvant chemotherapy and prognosis in triple-negative breast cancer

Background Triple-negative breast cancer (TNBC) has a high probability of relapse and poor overall survival. Neoadjuvant chemotherapy (NACT) is currently a routine treatment strategy for TNBC, but some patients do not respond well. T-LAK cell-originated protein kinase (TOPK) is highly expressed in breast cancer cells and contributes to cancer cell proliferation. The present study aimed to investigate the correlation of TOPK expression with NACT treatment response and prognosis in TNBC. Methods We collected 66 pairs of TNBC samples before and after NACT with docetaxel + epirubicin + cyclophosphamide (TEC). The Miller-Payne (MP) system was used to assess the therapeutic response to NACT in TNBC patients. Results Immunohistochemistry analysis showed that TNBC patients with high TOPK expression before NACT had a poor treatment response and a poor prognosis. The expression of TOPK after NACT was significantly higher than that before NACT in patients with MP grade 1–3. In contrast, patients with MP grade 4–5 had significantly lower TOPK expression after NACT than before NACT, and the expression change in Ki-67 in patients with MP grade 4–5 exhibited the same trend. Survival analysis revealed that patients with TNBC accompanied by elevated TOPK expression before NACT had a worse prognosis than those with lower TOPK expression. Conclusion TOPK may be a novel predictor for the therapeutic response to NACT and prognosis for patients with TNBC.