Comparison of different criteria for estimating major pathological response in resectable non-small cell lung cancer treated with neoadjuvant chemoimmunotherapy

Major pathological response (MPR) is proposed as a surrogate endpoint for survival in non-small cell lung cancer (NSCLC) after neoadjuvant chemoimmunotherapy. However, the criteria for estimating MPR differ between the recommendations of the International Association for the Study of Lung Cancer (IASLC) and the immune-related pathologic response criterion (irPRC). IASLC's criteria focus solely on evaluating the primary tumor, while irPRC's criteria encompass both the primary tumor and lymph node metastasis. Our objective is to compare the prognostic value of different criteria for estimating MPR. We conducted a retrospective study on a cohort of 235 patients with NSCLC after neoadjuvant chemoimmunotherapy. The survival endpoint was event-free survival (EFS). The MPR status of each patient was evaluated using both IASLC's criteria and irPRC's criteria. The prognostic value was compared using the Area Under Curve (AUC). The MPR rates were 63.4 % (149/235) and 57.4 % (135/235) according to IASLC's and irPRC's criteria, respectively. Inconsistent cases, characterized by MPR status according to IASLC's criteria but non-MPR status according to irPRC's criteria, constituted 6.0 % (14/235) of the overall cohort and 15.2 % (14/92) of patients with pretreatment N positive disease. Interestingly, all inconsistent patients showed no recurrence during the study period. Although both MPR statuses according to IASLC (p = 0.00039) and irPRC (p = 0.0094) were associated with improved EFS, IASLC's criteria (AUC = 0.65) were superior to irPRC's criteria (AUC = 0.62) with a higher AUC value. IASLC's criteria for estimating MPR were superior to irPRC's criteria in predicting EFS for NSCLC after neoadjuvant chemoimmunotherapy.