Real-world data on once or twice daily radiotherapy and the effect of age in patients with limited-stage small cell lung cancer.

Abstract

We aimed to assess acute toxicity and overall survival (OS) in patients with limited-stage small cell lung cancer (LS-SCLC) who received concurrent thoracic chemoradiotherapy using either once-daily (OD) or twice-a-day (BID) radiotherapy and compare these outcomes in two age groups. Data from the Dutch Lung Cancer Audit-Radiotherapy was prospectively recorded. Acute 90-day toxicity and OS in patients treated with OD and BID radiotherapy were compared in patients younger and older than 70 years. Survival was assessed in a multivariable Cox model. Acute toxicity, was assessed in a multivariable logistic regression model. 711 LS-SCLC patients starting treatment between 2016 and 2023 were included. Mean age was 66.7 years (SD 8.5). 59.8% patients were younger than 70 years, of which 85.2% were treated with a BID regimen. In younger patients treated BID, median OS was significantly longer (36.0 versus 22.2 months, adjusted hazard ratio (aHR) 0.61; 95%CI 0.41-0.89, p=0.01). In patients ≥70 years, 80.4% were treated BID. There was no difference in OS (21.8 versus 24.3 months, aHR 1.3; 95%CI 0.76-2.28). No difference in acute toxicity was observed in younger patients treated BID (26.0%) versus OD (30.2%) (OR 0.85; 95%CI 0.41-1.84). Older patients treated BID had numerically higher toxicity (28.1%) compared to patients treated OD (19.5%) (OR 1.43; 95%CI 0.57-3.77). A significantly longer OS in younger LS-SCLC patients treated with a BID radiotherapy compared to OD was observed, without increase of acute 90-day toxicity. No difference in OS between regimens in patients 70 years or older was found.