Induction chemoimmunotherapy may improve outcomes to chemoradiotherapy for unresectable stage III NSCLC patients

Abstract Objective Currently, the value of induction chemoimmunotherapy before chemoradiotherapy (CRT) in unresectable stage III non-small cell lung cancer (NSCLC) has not been established. This study aimed to investigate the role of induction chemoimmunotherapy for unresectable stage III NSCLC. Patients and Methods Patients diagnosed with stage III NSCLC who received CRT at Tianjin Cancer Hospital between August 2014 and December 2021 were retrospectively analysed. Based on induction chemoimmunotherapy or not, patients were allocated to I-CRT group or CRT group. Clinical outcomes including progression-free survival (PFS) and overall survival (OS) were estimated. Results A total of 255 patients were included, with 51 (20.0%) in the I-CRT group and 204 (80.0%) in the CRT group. The median PFS was 24.8 months in the I-CRT group vs. 12.6 months in the CRT group (p = 0.004), and the median OS was not reached (NR) vs. 32.4 months (p = 0.040). The multivariate analysis showed that induction chemoimmunotherapy was the independent factor favoring PFS (HR = 0.497, p = 0.003) and OS (HR = 0.459, p = 0.038). No significant differences were found in adverse effects (p > 0.05). The objective response rate (ORR) after induction chemoimmunotherapy was significantly higher than that after induction chemotherapy (56.9% vs. 22.2%, p = 0.000). Patients with induction chemoimmunotherapy before concurrent chemoradiotherapy had prolonged PFS (median NR vs. 14.9 months, p = 0.012) and OS (median NR vs. 26.5 months, p = 0.074) compared to those with induction chemotherapy. Conclusion Induction chemoimmunotherapy may improve outcomes to CRT and is well tolerated for unresectable stage III NSCLC patients. Prospective randomized trials need to be performed to further validate these findings.