The neoadjuvant chemotherapy responses and survival rates of patients with different molecular subtypes of breast cancer.

OBJECTIVE

The purpose of this study was to evaluate the effect of neoadjuvant chemotherapy (NAC) on the responses and survival rates of patients with different molecular subtypes of breast cancer.

METHODS

A retrospective analysis was conducted on 284 breast cancer patients who underwent NAC in our hospital from January 2017 to January 2019. The patients were classified into the Luminal A (n=87), Luminal B (n=78), human epidermal growth factor receptor 2 positive (HER-2, n=66), and triple-negative (TN, n=53) breast cancer subtypes. The Ki67 expressions and clinical prognoses were compared among the patients in the four subtypes.

RESULTS

The complete response (CR) rates were significantly higher in the HER-2 and TN patients than they were in the Luminal A and Luminal B subtype patients (P<0.05). The HER-2 and TN breast cancer patients had significantly higher response rates (RR) than the Luminal B patients (P<0.05). The Ki67 expressions decreased significantly in the patients with the Luminal B, HER-2, and TN subtypes after NAC (P<0.05), with a greater decrease in the Ki67 expressions in the HER-2 and TN subtypes than in the Luminal B subtypes (P<0.05). The Ki67 levels decreased significantly in the patients with CR or PR compared to the stable disease (SD) and progressive disease (PD) patients (P<0.05). The HER-2 patients had remarkably higher distant metastasis rates, compared to the patients with the Luminal A and B subtypes (P<0.05).

CONCLUSION

Statistical differences were found in the pathological responses and survival rates in the patients with the different molecular subtypes of breast cancer after the NAC treatment. The HER-2 or TN breast cancer patients had higher pathological response rates, which may be closely related to their decreased Ki67 expressions. Interestingly, the HER-2 breast cancer patients also showed a higher distant metastasis rate, which warrants further analysis.