Radiographic tumor regression as a predictor for pathologic response after neoadjuvant therapy for non-small cell lung cancer.

Objective: This study evaluated correlations between radiographic tumor response and pathologic response to neoadjuvant therapy in non-small cell lung cancer. Methods: All patients with stage IB-IV non-small cell lung cancer treated with neoadjuvant therapy and surgery between 2015 and 2025 in a large health system were included. Demographics, pathologic, treatment, and radiographic data were collected. Per Response Evaluation Criteria In Solid Tumors 1.1, patients were stratified by radiographic tumor size decrease ≥30% from baseline (objective radiographic response, ORR) versus decrease <30% (radiographic stable disease). Major pathologic response and pathologic complete response (pCR) were determined by pathologist review. Results: Among 79 patients with computed tomography scans taken before neoadjuvant therapy and before surgery, 63 patients had pathologic tissue evaluation, with 44% (n = 35) showing ORR. Patients with ORR were more likely to attain pCR (33% vs 10%, Conclusions: Radiographic reduction in tumor size and decreased PET SUVmax were significantly associated with pCR after neoadjuvant therapy. Although most patients with ORR attained pCR, viable tumor persisted in some patients with ORR and, conversely, there were some patients who had complete or major pathologic response despite radiographic stability after neoadjuvant therapy. Our findings demonstrate that radiographic response can reflect pathologic response, and with further validation, may provide an objective marker for long-term outcomes.