Increased number of chemotherapy cycles during radiochemotherapy improves overall survival without increasing toxicity in locally advanced non-small cell lung cancer patients.

Purpose

Radiochemotherapy (RCHT) followed by immunotherapy is the standard of care for unresectable, locally advanced non-small cell lung cancer (LA-NSCLC) patients. However, the impact of chemotherapy cycles and consolidation durvalumab on overall survival and toxicity remains uncertain in a real-life cohort.

Methods

We retrospectively analyzed 90 patients with stage IIB-IIIC LA-NSCLC treated with definitive RCHT (56-66 Gy, using weekly carboplatin/paclitaxel). Fifty of these patients received consolidation durvalumab. Chemotherapy cycles were analyzed as a stratified variable (1-4 vs. 5-7 cycles) and as a continuous predictor. Patients were also stratified by durvalumab administration. Early and late toxicities grade ≥ 2 were evaluated according to CTCAE v5.0. Overall survival (OS) was assessed via Kaplan-Meier analysis, log-rank test, Cox regression.

Results

Median follow-up was 33.5 months. Patients receiving 5-7 chemotherapy cycles had significantly longer OS than those with 1-4 cycles (p = 0.048). This finding was confirmed when treating the cycle number as a continuous variable (HR = 0.75 per additional cycle; p = 0.017). Durvalumab showed a trend towards improved OS (p = 0.075). No significant increase in early or late toxicity was observed with more chemotherapy cycles. Amongst the toxicity parameters, early grade ≥ 2 anemia (27.8%) was associated with worse OS (p = 0.006).

Conclusion

Receipt of 5-7 chemotherapy cycles during RCHT was associated with improved OS without an increase in grade ≥ 2 toxicity. Early anemia emerged as a key prognostic marker and was closely linked to chemotherapy de-escalation. In addition, OS estimates in durvalumab-treated patients were broadly consistent with outcomes reported in pivotal post-CRT immunotherapy trials.