Complete response and long-term survival to endocrine monotherapy in a patient with metastatic breast cancer in a low-income country: a case report.

Background: Breast cancer is the most common cancer in women. Progression-free survival for hormone receptor-positive/human epidermal growth factor receptor-2-negative metastatic breast cancer treated with endocrine therapy in combination with cyclin4/6-dependent kinase is approximately 25 months. This case represents metastatic breast cancer treated with endocrine therapy, leading to long-term survival.