What happened, in summary

A 65-year-old woman with no smoking history was diagnosed with Stage IIIA lung squamous cell carcinoma after chest CT showed a left-lung lesion with enlarged para-aortic lymph nodes. PET-CT showed high glucose uptake in the lung mass and involved lymph node. CT-guided biopsy confirmed lung squamous cell carcinoma, supported by hematoxylin-eosin staining and p40 staining. The tumor was staged T2aN2M0, and PCR testing identified an EGFR exon 19 deletion. She entered a phase 2 clinical trial of neoadjuvant targeted therapy for EGFR-mutated non-small cell lung cancer. Starting 30 August 2022, she took aumolertinib 110 mg by mouth daily for 4 cycles, or 16 weeks. Surveillance CT showed the primary tumor decreasing from 38.8 mm to 9 mm, while the metastatic lymph node decreased from 26.2 mm to 6 mm. PET-CT also showed major metabolic improvement, with the tumor SUVmax falling from 16.05 to 0.99 and the lymph-node SUVmax from 16.74 to 2.26. After stopping neoadjuvant aumolertinib for 1 week, she had video-assisted left upper lobectomy with lymph-node dissection. Surgical pathology showed pathologic complete response, with no viable tumor cells in the resected lung tumor or lymph nodes. She continued adjuvant aumolertinib after surgery and was instructed to stay on it for 3 years. At the 1 April 2024 cutoff, she had no recurrence after 20 months of treatment. Reported side effects were grade 1 only, including low lymphocytes, liver-enzyme elevation, chest pain, diarrhea, and fatigue. No surgery-related complication was observed. The response was both radiographic and pathologic: imaging showed major tumor and lymph-node shrinkage, while the surgical specimen showed no remaining viable cancer cells.