Recurrent breast cancer with pleural disease: capecitabine stopped after cardiac complications

What happened, in summary

This 53-year-old postmenopausal woman had left breast cancer diagnosed in 2015. Treatment at that time included surgical resection, adjuvant radiotherapy to the left chest wall and regional lymphatics at 50 Gy in 25 fractions over 5 weeks, and FU-based chemotherapy with 5-FU. She achieved complete remission and was declared cancer-free before 2024. In early 2024, cancer returned in the pleura, the lining around the lung, and histopathology confirmed recurrence. She underwent left-sided pleurodesis and started capecitabine. Six months later, in October 2024, she was hospitalized with cardiac tamponade and required drainage of 2 liters of hemorrhagic pericardial fluid. Cytology of the pericardial fluid was negative for cancer cells, making malignant pericardial involvement less likely, though not completely excluded because no pericardial biopsy was performed. Echocardiography during that hospitalization showed preserved left ventricular ejection fraction at 60%, and she was also diagnosed with right subclavian vein thrombosis and started on apixaban. Because of cardiac involvement, capecitabine was stopped. By January 2025, imaging showed new left ventricular dysfunction with ejection fraction reduced to 45%, and she reported NYHA class III exertional dyspnea. Coronary angiography ruled out significant coronary artery disease, and NT-proBNP was elevated at 2500 pg/mL. Echocardiography, cardiac MRI, and catheterization supported chronic constrictive pericarditis with evolving constrictive physiology. Treatment included diuretics, direct oral anticoagulants, carvedilol, and ramipril. Pericardectomy was proposed, but she declined surgery. As of May 2025, 3 months later, she had stable NYHA class II dyspnea without decompensated heart failure and remained under medical management while living with recurrent pleural breast cancer.