FCGR3A V158F gene polymorphism and trastuzumab response in HER2-positive breast cancer patients

Breast cancer is considered a multifactorial disease, with genetic factors playing an important role in diagnosis and treatment. FCGR3A encodes the receptor for the Fc portion of immunoglobulin G that has been linked to the trastuzumab response. Our study aimed to investigate the association of FCGR3A-V158F gene polymorphism with breast cancer and to evaluate the impact of FCGR3A-V158F gene polymorphism on trastuzumab response in HER2-positive breast cancer patients. The study was conducted on eighty breast cancer patients who were collected from the Department of Oncology at Ain Shams University Hospitals; in addition, twenty age-matched healthy subjects were taken as a healthy control group. Patients were further sub-classified according to their responses. The study showed that there were no statistically significant differences between patients and controls regarding FCGR3A-V158F gene polymorphism genotypes. However, there was a significant association between the concordance of this polymorphism and the response to trastuzumab therapy among the patient's group. V/V is associated with better treatment response and overall survival (OS) compared to F/V and F/F alleles. Assessment of FCGR3A-V158F gene polymorphism might be useful in making a treatment decision in HER2-positive breast cancer patients.