PTEN rs701848 Polymorphism is Associated with Trastuzumab Resistance in HER2-positive Metastatic Breast Cancer and Predicts Progression-free Survival

Trastuzumab is an effective therapeutic approach for HER2-positive metastatic breast cancer (BC). However, a considerable number of patients develop resistance along the course of the disease. PTEN rs701848 polymorphisms are associated with an increased risk of developing cancer and have a potential role in predicting drug resistance.We studied the significance of PTEN rs701848 variants as significant predictors for trastuzumab resistance in HER2-positive metastatic BC patients. Therefore, considering their value in predicting clinical outcomes.This case-control study was conducted among female patients with HER2-positive metastatic breast cancer who underwent Trastuzumab therapy during the period from March 2017 to December 2020. PTEN rs701848 genotypes were analyzed in 160 HER2-positive metastatic breast cancer who received Trastuzumab therapy and clinically monitored for therapeutic response.PTEN rs701848 is deemed a significant predictor of Trastuzumab resistance and an independent prognostic factor of progression-free survival (PPFS). In particular, the C allele is associated with increased risk for Trastuzumab resistance and shorter PFS as compared to the homozygous TT genotype.PTEN rs701848 is significant predictor of trastuzumab resistance. Therefore, their value in predicting clinical outcomes is recommended.