[Update on the regression grading of non-small cell lung cancer]

Immune checkpoint inhibitors combined with conventional chemotherapy have led to significantly improved outcomes in the neoadjuvant and perioperative treatment of non-small cell lung cancer (NSCLC), establishing chemoimmunotherapy as the standard of care for patients in UICC stages IIA-IIIA. As a result, pathological assessment of therapy-induced tumor response has become essential. This article provides an overview of the current recommendations for macroscopic handling, histological evaluation, and staging of NSCLC resection specimens after neoadjuvant treatment. Key aspects include comprehensive embedding of the tumor bed, quantitative assessment of tumor bed components (viable tumor, stroma/inflammation, necrosis) in 10% increments, and the application of established regression grading systems (IASLC, Junker). Challenges in distinguishing therapy-induced changes, evaluating lymph nodes, and determining post-treatment staging are discussed. Current findings highlight the need for standardized diagnostic procedures and further research to identify predictive biomarkers and improve the prognostic value of pathological regression grading after neoadjuvant chemoimmunotherapy.