What happened, in summary

A 43-year-old woman who had never smoked was diagnosed in August 2016 with invasive mucinous adenocarcinoma of the left lung. The 6.4 cm primary tumor was accompanied by nodules in both lungs, establishing Stage IV disease. Testing found no common ALK, ROS1, EGFR, BRAF, KRAS, MET, or HER2 driver alteration and no initial PD-L1 expression.

She received cisplatin, pemetrexed, and bevacizumab, achieving a partial response before moving to bevacizumab and pemetrexed maintenance. Nivolumab did not control the cancer. Further testing then identified a CD74-NRG1 fusion, and afatinib began at 40 mg daily. A partial response was documented after 13 months and continued beyond 18 months.

When a residual left-lung tumor enlarged, she underwent left lower lobectomy and mediastinal lymph-node dissection. All 16 nodes were negative, and the residual tumor showed extensive treatment effect. Afatinib continued until bone metastases appeared in the spine, femoral head, and sacrum after 24 months. She restarted carboplatin and pemetrexed and received palliative radiation to the spine and sacrum. A later right-adrenal metastasis was detected, and she remained alive on treatment.