What happened, in summary

This 54-year-old woman was diagnosed in May 2023 with small-cell lung cancer in the left upper lobe. At diagnosis, the cancer involved the left hilar, mediastinal, and left supraclavicular lymph nodes and was associated with pericardial effusion, giving Stage IVA / extensive-stage disease. She had never smoked and had no known asbestos, radon, arsenic, chromium, or nickel exposure. Her main symptoms were chest tightness and shortness of breath with exertion. Treatment began on May 12, 2023 with etoposide, carboplatin, and durvalumab every 3 weeks. After 2 cycles, her chest symptoms improved and CT showed marked reduction in the primary lung lesion and involved lymph nodes. At the same time, new bone-density changes appeared throughout the chest and abdomen. Bone scan and MRI looked concerning for extensive osteoblastic metastases, but she had no bone pain or activity limitation. Bone marrow aspiration, CT-guided iliac bone biopsy, and additional laboratory testing found no tumor cells and did not support multiple myeloma, hyperparathyroidism, rheumatoid arthritis, Paget disease, or tuberculosis. Her team interpreted the bone findings as a grade 1 immune-related skeletal change from durvalumab rather than bone metastasis, so immunotherapy continued without steroids. After 6 cycles, the lung and nodal disease had partially responded, the pericardial effusion disappeared, and bone changes stayed stable. From November 2023 to February 2024, she received chest radical radiation and developed mild radiation pneumonitis treated with a prednisone taper and temporary durvalumab pause. As of March 2024, she had a clinical complete response and resumed durvalumab maintenance every 4 weeks.