Study of serum microRNA-99a relative expression as a diagnostic and prognostic noninvasive biomarker of breast cancer in Egyptian females

Abstract

BackgroundBreast cancer (BC) is the most significant cause of malignancy deaths among females in Egypt as well as in other countries. Despite the evident miR-99a deregulation in many malignancies, including breast cancer, its serum level and clinical significance in breast cancer are still vague. This study assessed the role of dysregulation of serum levels of miR-99a in the diagnosis and prognosis of breast cancer in Egyptian females. MethodsBlood samples were obtained from 60 breast cancer females diagnosed as invasive ductal carcinoma and 40 healthy females of matched age. Samples were evaluated for miR-99a relative expression using SYBR green-based real-time RT-PCR technology. Also, the association between serum miR-99a expression and CA 15–3, the known tumor marker of breast cancer, was investigated. ResultsThe serum expression level of MiR-99a was lower in the breast cancer group than that of the control group (P < 0.001). MiR-99a was 76.7% sensitive and 95% specific in the diagnosis of breast cancer and its level correlated with many clinical parameters of breast cancer, including primary tumor extent (P = 0.021), TNM stage (P < 0.001), and histological grade of cancer (P = 0.003). Regression analysis revealed that lower miRNA 99a expression was considered as an independent predictor for the higher BC tumor stage. ConclusionExpression of serum miR-99a was downregulated in breast cancer offering early diagnosis and indicating poor prognosis of cases.