and Polymorphisms in Early HER2-Positive Breast Cancer Patients: Relationship with Response to Neoadjuvant Anti-HER2 Treatment.

The addition to chemotherapy of anti-HER2 drugs such as trastuzumab or pertuzumab has improved outcomes in HER2-positive breast cancer patients. However, resistance to these drugs in some patients remains a major concern. This study examines the possible association between the response to neoadjuvant anti-HER2 treatment in breast cancer patients and the presence of 28 SNPs in 17 genes involved in different cell processes (, , , , , , , , , , chr6 intergenic region, , , , , , and ). Tumor samples from 50 women with early breast cancer were genotyped using the iPlexGold chemistry and MassARRAY platform, and patients were classified as good responders (Miller-Payne tumor grades 4-5) and poor responders (Miller-Payne tumor grades 1-3), as assessed upon surgery after 6 months of treatment. Proportions of patients with the (rs1058808) SNP double mutation were higher in good (58.62%) than poor (20%) responders ( = 0.025). Similarly, proportions of patients carrying the synonymous SNP rs2070096 () (wv + vv) were higher in patients showing a pathological complete response (46.67%) than in those not showing this response (15.15%) ( = 0.031). The SNPs rs1058808 () and rs2070096 () were identified here as potential biomarkers of a good response to anti-HER2 treatment.