Complete and Durable Response to Tamoxifen and Ovarian Ablation in the Treatment of Metastatic Breast Cancer

Most breast cancers are hormone receptor-positive, and tamoxifen is the mainstay of endocrine therapy for such patients. However, with the introduction of aromatase inhibitors and then fulvestrant, tamoxifen became a less preferred drug, even in a premenopausal setting. Many new approaches to tackle the recently identified resistance pathways for endocrine therapy are widely used. Cyclin-dependent kinase 4/6 inhibitors such as ribociclib, palbociclib, and abemaciclib, and inhibitors of the mechanistic target of rapamycin such as everolimus, are effective but have been associated with considerably higher costs and distinctive toxicities. We describe the clinical course of a young patient with advanced-stage breast cancer living in an under-resourced region who failed to respond to chemotherapy, including both anthracyclines and taxanes, but achieved complete and durable response to tamoxifen and ovarian ablation therapy. This case demonstrates the value of well-established, low-cost endocrine therapy for breast cancer. It also highlights the need to address the sequencing of endocrine therapy for patients in low-income countries.