Studies Evaluate Thoracic Radiotherapy Approaches in Lung Cancer
Two studies report on thoracic radiotherapy for lung cancer: a phase III trial found adding radiotherapy to chemoimmunotherapy did not improve survival in extensive-stage small cell lung cancer, while a retrospective review showed high local control rates with single-fraction 28 Gy stereotactic body radiotherapy.
Two separate studies on thoracic radiotherapy for lung cancer have reported findings, with one showing no benefit from adding radiotherapy to chemoimmunotherapy in extensive-stage small cell lung cancer, while another retrospective review found high local control rates with single-fraction stereotactic body radiotherapy for lung tumors.
A phase III trial testing whether thoracic radiotherapy could improve outcomes in patients with extensive-stage small cell lung cancer was stopped early for futility and safety concerns. The trial randomized 228 patients from 20 European hospitals to receive either chemoimmunotherapy plus thoracic radiotherapy or chemoimmunotherapy alone. All patients received four courses of carboplatin, etoposide, and durvalumab. In the thoracic radiotherapy group, radiotherapy was delivered as 30 Gy in 10 fractions to thoracic lesions. The median age was 68 years, with 50.4% women and 96.1% having stage IV disease.
The addition of thoracic radiotherapy did not improve overall survival. Median overall survival was 10.0 months in the thoracic radiotherapy group compared with 11.1 months in the chemoimmunotherapy-alone group. The hazard ratio was 1.12, with a 95% confidence interval of 0.82–1.54. Progression-free survival was also unchanged, with median progression-free survival of 5.1 months in both groups. Overall response rates were nearly identical at 88.5% and 89.6%. Adverse events were more frequent among patients who received thoracic radiotherapy.
In a separate retrospective review, 130 patients treated with single-fraction 28 Gy stereotactic body radiotherapy to lung tumors between February 2022 and April 2023 were analyzed. The median follow-up was 22 months. 81% of patients were treated for a primary lung tumor. Estimated Kaplan–Meier 1-year local control rates were 95.7% for primary tumors and 89.1% for metastases. 2-year local control rates were 86.9% for primary tumors and 76.3% for metastases.
Toxicity in the retrospective review was manageable, with 21% of patients experiencing acute grade 1–2 toxicities, most commonly fatigue and temporary chest wall pain. 18% of patients experienced late grade 1-2 toxicities, most commonly asymptomatic pneumonitis and chest wall pain. There was no reported grade 3 or higher acute or late toxicities.