Breast Cancer
Breast Cancer is the most commonly diagnosed cancer in women worldwide, with over 2.3 million new cases annually. The disease encompasses heterogeneous subtypes classified by hormone receptor status (estrogen receptor ER, progesterone receptor PR) and HER2 (human epidermal growth factor receptor 2) expression. Major subtypes include hormone receptor-positive/HER2-negative (approximately 70% of cases), HER2-positive (15-20%), and triple-negative breast cancer (TNBC, 10-15%), each with distinct biological behavior and therapeutic vulnerabilities.