P13K/AKT/mTOR Pathway-Based Novel Biomarkers for Breast Cancer

Background: Breast cancer has been the most recurrent frequent cause of cancer-related deaths in women in India and all around the world. The treatment options have been reportedly more effective in terms of cure at the initial stages of diagnosis, while at the advanced stages, the treatment still remains a great clinical challenge. Many targeted therapies have been reported earlier, which have given impetus to find novel therapies that may lead to increased survival rates in breast cancer patients. Methodology: The available literature using PubMed, Scopus and Google Scholar database was thoroughly reviewed using the keywords: breast cancer; P13K/AKT/mTOR; inhibitors; therapeutics; biomarkers and diagnosis. This narrative review of all the relevant papers with significant citations leads the authors to greater insight into the potential therapeutics against breast cancer. Results: In most breast cancers, the essential phosphoinositide-3-kinase/AKT/ mammalian rapamycin target (PI3K/AKT/mTOR) signalling pathway has reportedly been triggered, leading to excessive cell growth and tumor formation. The targeting of this important pathway is, therefore, an area of wide-clinical interest, particularly in the breast cancer treatment. Taking these details into account, the current review has reviewed preclinical and clinical studies where a variety of PI3K/Akt/mTOR pathway inhibitors (acting at different levels) have been used either alone or in conjunction with other cancer treatment agents. Conclusion: This review includes a detailed understanding of the structure and regulation/deregulation of mTOR, in addition to targeted therapies and the role of mTOR inhibitory drugs in the treatment of breast cancer, along with first and second generations PI3K/AKT/mTOR pathway inhibitors