Pyrotinib for HER2-amplified non-small cell lung cancer patient after progression to Afatinib: a case report.

Contrary to the success of antihuman epidermal growth factor receptor 2 (HER2) therapy in HER2-amplified breast cancer, the optimal targeted drug therapy for HER2-amplified lung cancer remains to be determined clinically. In this report, a nonsmoker, Chinese, old, male patient was diagnosed with cT2bN3M0 nonsmall cell lung cancer with genetic testing revealing HER2 amplification. Though the patient received successful microwave ablation, the results of reexamination after two cycles of afatinib monotherapy showed disease progression. Then the treatment regimen was switched to pan-HER inhibitor pyrotinib 400 mg daily, with which the patient remained with stable disease for 9 months. After computed tomography showed tumor enlargement in October 2021, anlotinib was added to the present treatment. This case suggests that pyrotinib may provide a novel effective treatment option for HER2-amplified lung cancer.