Understanding drug resistance in breast cancer: Mechanisms and emerging therapeutic strategies

Breast cancer is one of the primary reasons for cancer-related death all around the world, and drug resistance poses a big challenge in its effective treatment. This review gives a detailed explanation regarding the complex mechanisms causing drug resistance in breast cancer, that are of two types one being intrinsic, and the other being acquired resistance. An elaborate discussion regarding hormone receptor-mediated resistance, including progesterone receptor and estrogen receptor pathways, is provided, emphasizing alterations in signaling cascades and epigenetic modifications. Similarly, the role of human epidermal growth factor receptor 2-positive breast cancer in developing resistance through mutations, receptor crosstalk, and downstream signaling disruptions is thoroughly examined. To combat multidrug resistance in breast cancer, several therapeutic strategies have been explored. This review discusses how nanotherapeutics show promise in managing drug efflux alongside enhancing drug targeting capabilities. The article discusses combination therapy strategies because they aim to combat resistance through multiple simultaneous target pathways. The application of phytochemicals represents a new approach for managing drug resistance through their natural bioactive compounds, which demonstrate anti-cancer capabilities. Understanding these molecular mechanisms and novel therapeutic interventions is essential for enhancing breast cancer outcomes and developing more effective strategies to combat resistance.