Current advances in breast cancer: Implications for developing new treatment strategies through epi-drugs on the road to modifying the epigenome

Breast cancer is one of the most commonly diagnosed neoplasms affecting women worldwide, and it remains a leading cause of both mortality and morbidity. While genetic predisposition plays a critical role in the development of this neoplasm, significant epigenetic dysregulations accompany existing variants. The emergence of acquired drug resistance to current chemotherapeutics poses a significant challenge in managing therapy. However, progress has been made in developing novel agents that directly target epigenetic modifications. These agents, called epi-drugs, can be used alone in the clinic or in combination with current treatment regimens, offering the potential to create diversified effects on the disease's predictive process. Within the scope of this review, general information about the major epigenetic dysregulations in breast cancer will be provided, and their effects on the molecular mechanisms in the carcinogenesis process will be discussed. Furthermore, current treatment approaches for breast cancer will be explored, classifying these epi-drugs, such as DNA methyltransferase inhibitors (DNMTIs), histone deacetylase inhibitors (HDA-CIs), histone acetyltransferases (HATIs), and others that have been developed to target these mechanisms. Predictions regarding the future prospects of these epi-drugs are highlighted, and their contributions to the field of personalized medicine are emphasized based on the results obtained from clinical studies.