KEY POINTS
- This population-based retrospective study linked cancer registry, multidisciplinary meeting and radiotherapy data for 5,882 patients with stage I-III lung cancer diagnosed across Northern Ireland between 2010 and 2021.
- Use of radical radiotherapy increased from 16.6% in 2010-2013 to 30.6% in 2018-2021, while use of SABR-equivalent treatment with BED ≥100 Gy increased from 1.1% to 8.7%.
- Over the same period, five-year lung cancer-specific survival increased from 21.9% to 33.1%, an absolute improvement of 11.2 percentage points.
- In the most recent period, five-year cause-specific survival was 64.3% after radical surgery, 33.0% after radical radiotherapy, and 11.8% among patients receiving no active treatment. These groups differed substantially in stage and fitness and should not be compared causally.
- After adjustment for demographics, comorbidity, stage, histology, surgery and systemic therapy, the survival hazard ratio for 2018-2021 versus 2010-2013 was 0.67 (95% CI 0.61-0.72). Adding radiotherapy use to the model attenuated this to 0.78 (95% CI 0.72-0.85), indicating that increased radiotherapy contributed materially to the observed temporal improvement.
- Importantly, radical radiotherapy expanded into less fit populations: the proportion of treated patients with performance status ≥2 increased from 9.3% to 24.8%, while those with Charlson comorbidity score ≥4 increased from 12.3% to 25.2%.
- The study remains observational and cannot establish causality. Changes in imaging, radiotherapy technology, systemic therapy and treatment selection occurred simultaneously over the 12-year period.
CLINICAL TAKEAWAY
This is strong real-world evidence that broader access to curative-intent lung radiotherapy can translate into population-level survival gains, including for patients previously considered too frail for radical treatment. It supports service expansion and more systematic assessment for radical radiotherapy, while not proving that radiotherapy alone caused the survival improvement.