Safety and efficacy of two-drug combination in elderly patients with locally advanced non-small cell lung cancer and validation of the Charlson Index as a predictor of survival.

Background: The best platinum-based chemotherapy regimen remains to be determined in elderly patients treated with definitive chemoradiotherapy for advanced non-small cell lung cancer (NSCLC). Predictive indexes for toxicity and survival are also needed to give the safest and most effective treatment for this population. Methods: This is a retrospective cohort study. Patients with histologically confirmed stage IIIA, IIIB or IIIC NSCLC over 70 years of age, treated with radiotherapy and chemotherapy, were included. Patients from two cancer centers treated between 12/2006 and 08/2019 were included in the data analysis. Results: Fifty-eight patients were enrolled in the study. The median age was 76.6 years [interquartile range (IQR): 71.6-83.4]. Thirty-nine patients were treated with concomitant chemoradiotherapy and 19 with a sequential strategy. The chemotherapy regimen consisted in a combination of platinum and taxanes. At a median follow-up of 52 months (IQR: 7-69), the 2-year progression-free survival (PFS) and overall survival (OS) were 35.5% and 66.9%, respectively. Male sex and a high Charlson index were identified as independent prognostic factors for worse OS. Acute grade 3-5 toxicities occurred in 34.4% of patients, including 1 grade 5 toxicity, and grade 3-4 late toxicities occurred in 17.2% of patients. In the whole cohort a high Charlson index was the only predictive factor for a higher risk of grade 3-5 acute toxicities (statistical trend in the concurrent cohort, P=0.06). Conclusions: The Charlson index correlated with toxicity and survival in elderly patients treated with chemoradiotherapy in locally advanced NSCLC. The addition of taxanes to platinum chemotherapy was safe in the present study and warrants further exploration.