Efficacy and surgical safety of sequential surgical resection after pembrolizumab plus chemotherapy for initial unresectable stage IIIB non-small cell lung cancer.

Introduction: Neoadjuvant immunochemotherapy is effective in resectable NSCLC. However, its role in unresectable stage IIIB NSCLC patients remains controversial. This study aimed to demonstrate the efficacy and safety of neoadjuvant immunochemotherapy followed by surgical resection to treat initial unresectable stage IIIB NSCLC patients.

Methods: This study retrospectively analyzed 59 initial unresectable stage IIIB NSCLC patients who received induction pembrolizumab combined with chemotherapy between June 2019 and April 2022. Clinical characteristics, radiological and pathological responses, and survival outcomes were collected and evaluated.

Results: Fifity-nine initial unresectable stage IIIB NSCLC patients were identified and divided into surgery (n = 23) and non-surgery (n = 36) groups with a median follow-up time of 15.0 months. The median PFS/DFS of the surgery group was significantly longer than the non-surgery group (not reached vs. 15.5 months, p = 0.0031). The median overall survival (OS) was not reached in both groups, and the OS rate was 100% (23/23) in the surgery group and 83.3% (30/36) in the non-surgery group. The pathological analysis suggested that 13 of 23 patients (56.5%) achieved major pathological response (MPR) or pathological complete response (pCR), and more squamous cell carcinoma cases were observed in the MPR group compared to the non-MPR group (p = 0.034). All patients in the surgery group had an R0 resection, and no surgical-related mortality was recorded; only three patients (13.0%) experienced any postoperative complications.

Conclusion: In this retrospective study, surgical resection after neoadjuvant immunochemotherapy was promising for initial unresectable stage IIIB NSCLC patients, with a high MPR rate and good surgical safety.