Serum microRNA-210 as a predictor of neoadjuvant chemotherapy resistance in breast cancer

Breast cancer (BC) is a major global health issue as it is the most common malignancy in women. Despite, the role of neoadjuvant chemotherapy (NAC) in early BC has been established, there is a non-small proportion of patients who might develop chemoresistance. Several studies have investigated the relationship between microRNA-210 (miRNA-210) and neoadjuvant chemoresistance in BC with controversial results. Thus, this study aimed to evaluate the role of miRNA-210 as a predictor for chemoresistance in BC receiving NAC. The study enrolled 15 chemo-sensitive and 15 chemo-resistant patients with BC receiving NAC. In addition, 10 newly-diagnosed BC patients before treatment and 10 healthy women were recruited as controls. Serum samples from all patients and controls were withdrawn and measurements of miRNA-210 levels using quantitative real-time reverse transcriptase-polymerase chain reaction (qRT-PCR) were done and compared. The median value of miRNA-210 level was 1.53, 0.27, 0.52, and 1.35 in chemo-sensitive, chemo-resistant, newly-diagnosed, and control groups, respectively. A statistically significant difference (Chi square = 9.801, p = 0.020, df = 3) was found in the mean serum miRNA-210 among the four different groups. Using logistic regression model, low serum miRNA-210 expression level was found to be a predictive factor of chemo-resistance with p = 0.038 (OR of 0.103, 95% CI = 0.012 –0.886). Using the receiver operating characteristic curve, it was found that the area under the curve (AUC) was 0.747 (95% CI = 0.550 –0.943). Serum miRNA-210 could be an effective predictive biomarker for chemoresistance in BC patients receiving NAC.