Stage IV luminal B breast cancer with liver, bone, and bone marrow metastases

What happened, in summary

A 36-year-old premenopausal Javanese woman, with a family history of advanced breast cancer in her mother, first noticed a left breast lump and nipple changes in 2020 but delayed evaluation for more than 3 years. In May 2023, she was hospitalized after fainting with severe anemia, thrombocytopenia, leukocytosis, elevated LDH, elevated uric acid, and later melena from severe thrombocytopenia. The left breast was hardened and prone to bleeding. Core biopsy showed invasive luminal B breast cancer: ER 90% positive, PR 20% positive, HER2-negative, and Ki-67 60%. Imaging showed liver metastases with multiple nodules, the largest about 1.6 cm, plus lytic thoracolumbar vertebral lesions. Bone marrow biopsy confirmed metastatic adenocarcinoma from breast carcinoma, explaining the hematologic crisis. Chemotherapy was initially considered but deferred because her blood counts made severe hematologic complications a major concern. She first received tamoxifen 20 mg plus leuprorelin 3.75 mg, but hot flushes, nausea, joint pain, severe pain, and bedbound decline made the regimen poorly tolerated. Treatment was changed to leuprorelin 3.75 mg monthly, letrozole 2.5 mg, ribociclib 600 mg every 4 weeks, and zoledronic acid as a bone-sparing agent. After 2 cycles, pain decreased, transfusion needs fell, and she began walking. By cycle 4, hemoglobin and platelets improved and she resumed daily activities. After cycle 6, laboratory blood parameters normalized. From September to December 2023, she had no clinical symptoms of metastatic breast cancer and was described as having sustained complete remission under this regimen, with monthly follow-up advised. The response was especially meaningful because her initial presentation included visceral crisis and bone marrow failure, making standard chemotherapy difficult to start safely. The improvement in hemoglobin and platelets is central to the outcome because bone marrow metastasis had driven the life-threatening cytopenias. The remission period was short, 4 months, so the outcome is better classified as responding well rather than cancer-free or definitively cured.