Influence of Insulin-Like Growth Factor 1 Gene Expression in Women with Breast Cancer: A Systematic Review

Abstract Background: Breast cancer, the leading cause of cancer death among women worldwide, one of the major risk factors for breast cancer is genetic changes. Changes in the expression levels of the insulin-like growth factor 1 (IGF-1) gene have been associated with increased risk and aggressiveness of breast cancer. The IGF-1 gene encodes the IGF-1 peptide that is present in most human tissues, as in the normal and neoplastic mammary gland. Here, we conducted a systematic review to investigate the influence of IGF-1 gene expression levels in women with breast cancer.Methods: PubMed, Scopus, and Web of Science databases were searched for relevant studies published between February 2 and May 15, 2019, using inclusion and exclusion criteria in accordance with PRISMA guidelines. We analyzed the studies to find association between IGF-1gene expression and breast cancer.Results: A growing number of studies in women with breast cancer support, with controversial results, the influence of IGF-1 gene expression levels on clinical-pathological factors, disease-free survival, overall survival, and resistance to tamoxifen.Conclusions: Therefore, the elucidation of IGF-1 gene expression patterns through further studies may enable the characterization of women at high risk for breast cancer, as well as the development of effective prognostic and therapeutic strategies.