Neoadjuvant Chemotherapy-Immunotherapy in Non-Small Cell Lung Cancer: Can Positron Emission Tomography Scan Predict Complete Pathologic Response?

Abstract

Several studies reported the survival benefit of neoadjuvant chemotherapy and immunotherapy (chemo-IO) for patients with operable non-small cell lung cancer vs chemotherapy alone. Uncertainty persists about real-world reproducibility of these findings as granular data outside clinical trials remain limited. We retrospectively analyzed prospectively maintained lung cancer registries and thoracic surgery databases from 2 high-volume Canadian thoracic oncology centers. Inclusion criteria were patients with proven clinical stage II-III non-small cell lung cancer who received at least 1 cycle of neoadjuvant chemo-IO. Survival curves were analyzed by the Kaplan-Meier test, and receiver operating characteristic curve analysis was performed to predict pathologic complete response (pCR) after neoadjuvant treatment according to standardized uptake value reduction. A total of 78 patients were included, with a median follow-up of 12.3 months. Adverse events from neoadjuvant chemo-IO occurred in 54% of patients, of which 47% were grade 1-2 and 14% were grade 3. The pCR was 24% for a cohort in which programmed cell death protein ligand 1 tumor proportion score ≥50% was present in 46% of patients. A sensitivity analysis of 39 patients with positron emission tomography scans before and after chemo-IO found that a 70% reduction in maximal standardized uptake value significantly correlated with pCR (area under the curve, 0.89; P = .01). This study supports the safety and short-term efficacy of neoadjuvant chemo-IO. Reduction in standardized uptake value on positron emission tomography scans was associated with pCR, indicating its potential as a surrogate biomarker pending further validation.