Pathological responses of primary tumor and lymph nodes in non-small cell lung cancer after neoadjuvant chemoimmunotherapy: a retrospective real-world study.

Background: In patients with non-small cell lung cancer (NSCLC) receiving neoadjuvant chemoimmunotherapy (NCIT), inconsistent pathological responses between the tumor and lymph nodes (LNs) are often observed. There has been limited evidence comparing the different responses of tumors and LNs in those patients. This retrospective real-world analysis intended to evaluate the clinical and pathological response of primary tumors and LNs, and the long-term outcomes in NSCLC patients after NCIT. Methods: We included resectable NSCLC patients who had received neoadjuvant therapy and had available clinicopathological records. The progression-free survival (PFS) and overall survival (OS) outcomes were analyzed using survival analysis. Results: In total, 204 patients were included in the final analysis. Patients were predominantly male (85.8%) and ever-smokers (66.2%), with a median age of 63 years. No significant difference was observed in intraoperative bleeding (P=0.51 and P=0.54) and operation time (P=0.57 and P=0.58) between the major pathologic response (MPR) and pathological complete response (pCR) group, respectively. Patients who were male (pCR, P=0.01; MPR, P=0.004), with squamous cell carcinoma (SCC) (pCR, P=0.02; MPR, P=0.001), and overall response rate (ORR) (pCR, P<0.001; MPR, P<0.001) demonstrated significantly higher rates of pCR and MPR. The median follow-up time for all patients in this study was 23 months. Patients with MPR (P=0.004) and pCR (P=0.02) experienced prolonged PFS, but not OS (MPR, P=0.08; pCR, P=0.15). In terms of yield pathological tumor MPR (ypTMPR) and yield pathological LNs stage (ypN), Kaplan-Meier analyses demonstrated that there was a better PFS for the ypTMPR(+)/ypN(0) group, followed by ypTMPR(-)/ypN(0), ypTMPR(+)/ypN(0), and ypTMPR(-)/ypN(1+2) (P=0.01). The average PFS time was 35.7, 31.7, 29.4, and 28.7 months, respectively. After achieving MPR, the probability of local recurrence or distant metastasis was 7.3%, 25%, 23.5%, and 23.7%, respectively. Conclusions: In this real-world study, the combination of tumor and LNs responses was significantly associated with prognosis, and we demonstrated that ypTMPR(+)/ypN(0) group had a better prognosis, followed by ypTMPR(-)/ypN(0), ypTMPR(+)/ypN(0), and ypTMPR(-)/ypN(1+2). We advocate for ypTMPR(+)/ypN(0) status as a better surrogate of PFS in resectable NSCLC patients after NCIT.