Objectives: To investigate relationships between several protein biomarkers and clinical responses to neoadjuvant chemotherapy (NAC) in breast cancer.
Methods: Tumour tissue samples from female patients with locally advanced breast carcinoma (stages IIA to IIIC), treated with NAC regimens (including 5-fluorouracil, epirubicin, cyclophosphamide and docetaxel, epirubicin, cyclophosphamide) were analysed retrospectively. Immunohistochemical analysis was used to test for protein levels of oestrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor (HER)-2, protein 53 (p53) and γ-synuclein. Relationships between protein biomarkers and responses to NAC were analysed by multivariate logistic regression analysis.
Results: Data from 154 patients (median age, 51 years; range 27-75 years) were included. Multivariate logistic regression analysis showed that γ-synuclein was an independent predictor of NAC objective response rate, and a statistically significant relationship was observed between NAC regimen, γ-synuclein levels and pathological complete response rate.
Conclusions: These study findings suggest that γ-synuclein - in combination with other markers such as ER, PR and HER-2 - may serve as a biomarker for response to NAC in breast cancer and warrants further study.
Keywords: SNCG gene; breast cancer; human epidermal growth factor receptor 2 (HER-2); neoadjuvant chemotherapy; oestrogen receptor (ER); progesterone receptor (PR); sensitivity; γ-synuclein.