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

Abstract 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. Case presentation A 40-year-old Syrian woman diagnosed with hormone receptor-negative breast cancer was treated surgically with adjuvant chemotherapy and radiotherapy. She developed local and nodal recurrences that were hormone receptor-positive, followed by a recurrence of malignant pleural effusion. She was initially treated with chemotherapy and then placed on endocrine therapy with a complete response from 2014 until now. The patient also suffered from adverse events of medications, such as heart failure and osteoporosis, which were treated appropriately. Conclusion This case demonstrates a long-lasting complete response to metastatic breast cancer with malignant pleural effusion. This shows the validity of endocrine therapy in recurrent hormone receptor-positive breast cancer, especially in countries that cannot afford targeted therapies or genetic tests. It also highlights the necessity for a better understanding of the prognostic and predictive factors.