Recurrent Hormone Receptor–Positive Breast Cancer With Multiple Sites of Distant Metastasis: A Case Report and Review of the Literature

Breast cancer is one of the most common malignancies and the leading cause of cancer-related mortality among women worldwide, with hormone receptor-positive (HR+) breast cancer being the most common subtype. Current guidelines recommend endocrine therapy as the first-line treatment for HR+, human epidermal growth factor Receptor 2-negative breast cancer. In this case report, we describe a patient with HR+ breast cancer who developed bone and liver metastases after breast cancer surgery. We document the disease progression from initial treatment to managing local recurrence and treating distant metastasis using salvage chemotherapy combined with endocrine therapy. Importantly, following denosumab treatment, the patient experienced a bone flare; this presented as increased radionuclide uptake on bone scans, but was later confirmed as pseudoprogression. Furthermore, we note changes in the patient's pathology as the disease progresses.