Efficacy and Toxicity of Different Chemotherapy Protocols for Concurrent Chemoradiation in Non-Small Cell Lung Cancer—A Secondary Analysis of the PET Plan Trial

SIMPLE SUMMARY: Concurrent chemoradiation (cCRT) with a platinum-based doublet, followed by immunotherapy, is the treatment of choice in locally advanced non-small cell lung cancer. A remaining open question is the difference between cisplatin and carboplatin in combination with second and third generation agents for concurrent chemoradiation, as they have a substantially different toxicity profile and data are scarce and inconclusive concerning cCRT. We here present a secondary analysis of the international PET Plan trial in order to assess the efficacy and toxicity of different chemotherapy regimens as well as the difference between the commonly used platinum based agents, cisplatin and carboplatin. All regimens were well tolerated and cisplatin in combination with vinorelbin either as a single dose or daily doses per cycle showed comparable efficacy. Patients treated with carboplatin doublets had a worse survival, but after adjusting for possibly relevant factors, this difference became non-significant, probably due to existing selection bias. ABSTRACT: (1) Background: The optimal chemotherapy (CHT) regimen for concurrent chemoradiation (cCRT) is not well defined. In this secondary analysis of the international randomized PET-Plan trial, we evaluate the efficacy of different CHT. (2) Methods: Patients with inoperable NSCLC were randomized at a 1:1 ratio regarding the target volume definition and received isotoxically dose-escalated cCRT using cisplatin 80 mg/m(2) (day 1, 22) and vinorelbin 15 mg/m(2) (day 1, 8, 22, 29) (P1) or cisplatin 20 mg/m(2) (day 1–5, 29–33) and vinorelbin 12.5 mg/m(2) (day 1, 8, 15, 29, 36, 43) (P2) or carboplatin AUC1 (day 1–5, 29–33) and vinorelbin 12.5 mg/m(2) (day 1, 8, 15, 29, 36, 43) (P3) or other CHT at the treating physician’s discretion. (3) Results: Between 05/2009 and 11/2016, 205 patients were randomized and 172 included in the per-protocol analysis. Patients treated in P1 or P2 had a better overall survival (OS) compared to P3 (p = 0.015, p = 0.01, respectively). Patients treated with carboplatin had a worse OS compared to cisplatin (HR 1.78, p = 0.03), but the difference did not remain significant after adjusting for age, ECOG, cardiac function creatinine and completeness of CHT. (4) Conclusions: Carboplatin doublets show no significant difference compared to cisplatin, after adjusting for possibly relevant factors, probably due to existing selection bias.