Breast Cancer: A Comprehensive Review of Carcinogenesis, Classification, and Treatment Strategies

Breast cancer (BC) is the most frequently diagnosed cancer and the fifth leading cause of cancer-related death in females (Sung et al., 2021). Additionally, BRCA is among the most prevalent cancers among Chinese women (Cao et al., 2020). In 2020, approximately 2.3 million women received a BRCA diagnosis, with 685,000 of them succumbing to the disease (Sung et al., 2021; Lei et al., 2021). Despite notable advancements in diagnosis and treatment, the prognosis for some BC patients remains unfavorable (Waks & Winer, 2019). The histological classification of BRCA is primarily determined by the presence of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) (Yeo & Guan, 2017; Hong & Xu, 2022). These classifications include Luminal A, Luminal B, HER2-enriched, normal-like, and basal-like subtypes of BRCA (Polyak, 2007; Harbeck et al., 2019; Franzoi, Romano & Piccart, 2021). Currently, the treatment of BRCA primarily consists of radiation therapy, hormone therapy, chemotherapy, surgery, and targeted therapy, with varying drug combinations and targeted approaches showing promising results (Wang et al., 2021). Nevertheless, resistance to endocrine therapy remains a significant challenge despite considerable progress in the treatment of BRCA (Hanker, Sudhan & Arteaga, 2020). Chemotherapy continues to be the standard treatment regimen for advanced triple-negative breast cancer (TNBC) due to the absence of specific therapeutic targets (Bareche et al., 2018). However, the use of conventional chemotherapy drugs has limited efficacy in improving the rates of pathological complete response (Loibl et al., 2021). Therefore, it is crucial to further investigate the underlying mechanisms of carcinogenesis and therapeutic approaches in BC.