Stage IIIA squamous lung cancer with pathologic complete response after immunochemotherapy

What happened, in summary

This 50-year-old non-smoking woman was evaluated in May 2022 after developing cough, hoarseness, and blood in the sputum. Chest CT showed lesions in the right lung, involving the posterior segment of the upper lobe and the dorsal segment of the lower lobe. Bronchoscopy found a bronchial neoplasm, and pathology showed non-small cell lung cancer with a squamous component. The cancer was staged T4N0M0, Stage IIIA, and was considered potentially resectable. PD-L1 testing was high, with TPS 90% and CPS 100%. Genetic testing on the pretreatment biopsy later identified EGFR p.G719S and p.S768I mutations, a TP53 p.S183* mutation, and very low tumor mutational burden. In July 2022, she began neoadjuvant immunochemotherapy with tislelizumab, albumin-paclitaxel, and carboplatin. After 2 cycles, imaging showed a partial response, allowing radical lung resection. Surgical pathology then showed a complete response in the primary site and no lymph-node metastasis. She continued with 2 additional cycles of immunochemotherapy after surgery. The treatment sequence gave her both radiologic tumor shrinkage before surgery and pathologic clearance in the resected specimen. Follow-up imaging through March 2025 showed no recurrence or metastasis. Her postoperative disease-free survival exceeded 30 months, and overall survival exceeded 34 months. Her high PD-L1 expression and potentially resectable Stage IIIA status supported the neoadjuvant approach. The EGFR G719S/S768I findings were identified after surgery to guide postoperative planning, but the pathologic complete response limited the rationale for a separate targeted-therapy strategy. Her recovery remained durable on continued follow-up imaging, with no reported nodal or distant relapse.