What happened, in summary

A 40-year-old man with a smoking history presented with several weeks of shortness of breath. CT imaging showed numerous masses and plaques along the right pleura, a pleural effusion and extensive chest lymph-node disease. Biopsy identified SMARCA4-deficient undifferentiated non-small cell lung cancer. Molecular testing found BRCA1 and TP53 variants, and the tumor mutational burden was 12.6. He received 6 cycles of carboplatin plus paclitaxel, and follow-up imaging showed stable disease confined to the right chest. When shortness of breath worsened, treatment was changed to nivolumab. After one cycle, he developed weakness. MRI then found a new 4.5 cm mass in the spine causing spinal-cord compression. Neurosurgical removal confirmed that the spinal lesion was metastatic SMARCA4-deficient lung cancer. The new distant spread represented clear progression, and further outpatient treatment was planned.