Metastatic gastric cancer from breast carcinoma presenting with paraneoplastic rheumatic syndrome: A case report

BACKGROUND: Breast cancer is the most frequently diagnosed cancer worldwide. It is the leading cause of death by malignant disease in women. CASE SUMMARY: A female patient, 73 years of age, sought care due to weakness, mild abdominal pain, arthralgia, and weight loss. She was taking anastrazole as maintenance therapy for localized breast cancer and had moderate anemia and elevated acute-phase markers. Upper digestive endoscopy showed isolated erosion in the gastric corpus. This lesion was compatible with signet-ring cell adenocarcinoma in anatomopathological study and was confirmed as metastasis of a breast carcinoma in immunohistochemistry, which was positive for estrogen antibody. Further imaging studies determined numerous proximal bone metastases. The patient was treated with prednisone for paraneoplastic syndrome, which improved the anemia and rheumatic disease, and with chemotherapy, which greatly improved the symptoms. She has been followed-up for 6 mo, and her anemia, arthralgias, and acute phase markers have normalized. CONCLUSION: Systemic treatment strategies seem to be the best choice for gastric metastasis from breast cancer, resulting in disease control and relapse-free survival. Prospective studies with longer follow-up are needed to better understand the biological, pathological, and clinicopathological characteristics and outcomes of the endoscopic features associated with metastatic gastric cancer from breast carcinoma.