P-mTOR Expression and Implication in Breast Carcinoma: A Systematic Review and Meta-Analysis

Abstract

ObjectivePhosphorylated mammalian target of rapamycin (p-mTOR) is a promising prognostic marker in many types of cancer. However, its survival benefit in patients with breast carcinoma remains unknown. The aim of the present study was to assess the relationship between p-mTOR expression and prognosis in breast carcinoma based on a systematic review and meta-analysis.Materials and MethodsElectronic databases (including Pubmed, Embase, ISI web of science, and Cochrane Library) were searched up to November 24, 2015. The outcome measures were hazard ratios (HRs) with 95% confidence interval (CI) for the association between the prognosis of breast carcinoma patients and p-mTOR expression. Primary end points were disease-free survival (DFS), overall survival (OS), and recurrence-free survival (RFS). Statistical analysis was performed with STATA 12.0.ResultsNine cohort studies including 3051 patients met full eligibility criteria. The pooled HRs (95% CI) for OS, DFS, and RFS were 0.84 (0.27–2.63), 0.71 (0.40–1.23), and 0.48 (0.20–1.18), respectively.ConclusionsOur findings suggested that p-mTOR overexpression was not significantly related to prognosis in breast carcinoma regarding OS and disease recurrence. Prospective studies are warranted to examine the association between p-mTOR expression and survival outcomes in breast carcinoma.

Limited utility of tissue micro-arrays in detecting intra-tumoral heterogeneity in stem cell characteristics and tumor progression markers in breast cancer

“…mTOR is part of a pathway playing an important role in tumorigenesis. Our findings are in agreement with a recent study of Ding et al where no significant correlation between mTOR expression and clinical outcome was seen [ 59 ].…”

Assessment of the expression pattern of mTOR‐associated lncRNAs and their genomic variants in the patients with breast cancer

“…Previous studies have underscored the role of overactivation of the mTOR signaling pathway in breast carcinomas (Koboldt et al, 2012;Stephens et al, 2012). However, a recent metaanalysis failed to report the association between mTOR overexpression and overall survival or disease recurrence of patients with breast cancer and suggested further conduction of prospective studies in this regard (Ding et al, 2017). In spite of significant overexpression of mTOR in malignant tissues compared with the nonmalignant tissues, in the current study, we could not detect any association between clinical or histological determinants of patients' survival and expression levels of mTOR gene, which is in line with the results of the mentioned metaanalysis.…”

mTOR Repression in Response to Amino Acid Starvation Promotes ECM Degradation Through MT1‐MMP Endocytosis Arrest

“…[ 14 ] Dysregulation of the PI3K/Akt/mTOR signaling pathway is linked with breast cancer initiation and progression and regional heterogeneity in immunohistochemical profiles of phosphorylated (p)‑mTOR and its downstream signaling effectors, pS6K, and p4E‐BP1 have been described in relation with metabolic alterations. [ 15 , 16 ]…”