Optimum cycles of induction chemotherapy in concurrent chemo-radiotherapy management of unresectable stage III non-small cell lung cancer: Results from a single institutional database

Induction chemotherapy (IC) prior to concurrent chemo-radiotherapy is the recommended treatment for unresectable stage III non-small cell lung cancer (NSCLC). However, the optimum number of IC cycles for improved survival outcomes is still not known. Here, we assessed the efficacy of 2 or more cycles of IC for unresectable stage III NSCLC patients from our hospital. Data on unresectable stage III NSCLC patients treated with IC + concurrent chemo-radiotherapy at our hospital between 2018 and 2022 were retrieved and analyzed, and survival outcomes compared between IC = 2 and IC > 2 patients. Univariate and multivariate Cox regression, and Chi-square or Fisher exact test were used to assess prognosis and acute toxicity profiles. One hundred twenty-six patients were recruited; 90 for IC = 2 and 36 for IC > 2. Median follow-up time was 26 months [IQR 16-38]. Three-year overall survival was not statistically significant between the 2 groups (77.8% vs 75.0%, P =.453). Distant metastasis free survival, loco-regional recurrence free survival and progression free survival were also not significant, (90.0% vs 86.1%, P =.068), 97.8% vs 97.2%, P =.056), and (73.3% vs 66.7%, P =.446) respectively. Univariate and multivariate Cox regression analysis revealed smoking, T_stage, N_stage, and IC_regimen as independent prognostic factor for overall survival, while drinking and T_stage were risk factors for progression free survival. In summary, 2 cycles of platinum-based IC was effective for stage III unresectable NSCLC and adding more than 2 cycles did not offer extra survival benefits.