1093 - Real-World Outcomes of Radiotherapy Alone in 1802 Patients with Stage II-III NSCLC

05:15pm - 05:20pm ET

Room 107

Presenter(s)

Judi van Diessen, MD, PhD - NKI-AvL, Amsterdam, Noord-Holland

J. van Diessen¹, L. Niazi², S. V. Hassan¹, J. Belderbos¹, R. Damhuis³, and W. V. Theelen¹; ¹The Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital, Amsterdam, Netherlands, ²Faculty of Medicine, Amsterdam University Medical Center, Amsterdam, Netherlands, ³Comprehensive Cancer Organization, Utrecht, Netherlands

Purpose/Objective(s):

Elderly patients with stage II–III non–small cell lung cancer (NSCLC) are frequently treated with radiotherapy (RT) alone, as many are unfit for the standard-of-care regimen due to vulnerability and comorbidities. Clinical trials specifically addressing optimal RT strategies for the frail and elderly NSCLC patient are scarce, resulting in limited evidence on toxicity, survival outcomes, and appropriate RT dosing. To fill this gap, we analyzed real-world outcomes of frail and elderly patients with stage II–III NSCLC treated with RT alone from the national registry.

Materials/Methods:

Data from the Dutch Lung Cancer Audit–Radiotherapy (2017–2023), including 1802 patients with stage II–III NSCLC treated with RT alone were analyzed. Patients were treated with conventionally fractionated schedules with a total dose of 40-66 Gy in equivalent RT dose (EQD₂). Patients were stratified by age (<75 vs =75 years). Comorbidity was classified using an adapted index excluding age. Severe acute toxicity (dyspnea, dysphagia, other =grade 3; radiation pneumonitis (RP) =grade 2) and overall survival (OS) were assessed. Outcomes were compared between patients receiving 40–59 Gy versus =60 Gy. Multivariable Cox proportional hazards model analyses, adjusted for comorbidity, WHO performance status, tumor stage, smoking status, EQD₂ and tumor volume, were performed.

Results:

Of the 1802 patients, 937 (52%) were aged =75 years. The median follow-up was 37.2 months (range, 18.0-61.2 months). Overall, 139 patients (8%) developed =grade 3 acute toxicity and/or RP =grade 2 without significant difference between age groups. Severe acute toxicity was associated with worse OS, with a stronger effect in older patients (HR 1.67 vs 1.31). OS at 3 months, 1 year, and 5 years was 94%, 72%, and 33% in patients <75 years, compared with 92%, 67%, and 24% in patients =75 years. Age remained an independent predictor of mortality (HR 1.25, 95% CI 1.10-1.42). A lower RT dose (<60 Gy) was not associated with increased mortality, even after adjustment for confounders (HR 1.02, 95% CI 0.86-1.22).

Conclusion:

Elderly patients with stage II–III NSCLC treated with RT alone achieved meaningful survival outcomes, with severe treatment-related acute toxicity rates comparable to those in younger patients. However, in patients aged =75 years, toxicity can compromise OS, making careful patient selection essential for radical RT. Although age independently predicts mortality, these results show that select older patients tolerate and benefit from conventionally fractionated RT. Lower RT doses (<60 Gy) did not compromise OS, suggesting that individualized, tolerance-based dosing may achieve treatment safety without sacrificing efficacy. This substantiates personalized RT strategies for frail and elderly patients, aiming to optimize both OS and quality of life.

		Toxicity			=60 Gy
		HR	95% CI	P	HR	95% CI	P
	N
Age <75	865	1.31	0.94-1.81	0.11	1.11	0.83-1.47	0.50
Age =75	937	1.67	1.23-2.28	0.001	1.01	0.81-1.26	>0.90