Real-World Clinical Outcomes in Patients With Limited-Stage Small Cell Lung Cancer Who Received High-Dose Hyperfractionated Simultaneous Integrated Boost Radiation Therapy Versus Standard-Dose Radiation Therapy.

Abstract

A phase 3 trial has shown that high-dose, accelerated, hyperfractionated, twice-daily thoracic radiation therapy (54 Gy in 30 fractions) is clinically effective for patients aged <70 years with limited-stage small cell lung cancer (LS-SCLC). This retrospective study compares the real-world effectiveness of high-dose hyperfractionated simultaneous integrated boost radiation therapy with standard-dose radiation therapy. This retrospective study was conducted at Peking University Cancer Hospital, including patients with histologically or cytologically confirmed LS-SCLC. All eligible patients received 4 courses of thoracic radiation therapy combined with concurrent chemotherapy (cisplatin or carboplatin and etoposide). Patients were categorized into 3 groups based on the radiation therapy dose: (1) the 54 Gy group (54 Gy in 30 fractions, twice daily); (2) the 45 Gy group (45 Gy in 30 fractions, twice daily); and (3) the 60 Gy group (60-70 Gy in 30-35 fractions, once daily). The primary endpoints were real-world progression-free survival and overall survival. Between March 2010 and November 2024, a total of 353 patients were included in the study. The median follow-up was 54.9 months (range, 2.9-151.6 months). After applying inverse probability of treatment weighting (IPTW), the clinical features were well balanced between the groups. The median real-world progression-free survival was significantly better in the 54 Gy group (29.7 months [95% CI, 15.9-not reached]) compared with the 45 Gy group (15.0 months [95% CI, 11.8-30.4]; hazard ratio [HR], 1.23 [95% CI, 1.01-1.50]) and the 60 Gy group (13.5 months [95% CI, 11.4-15.9]; HR, 1.29 [95% CI, 1.09-1.54]) both before (P = .011) and after (P = .033) IPTW. The median overall survival was also significantly longer in the 54 Gy group (63.9 months [95% CI, 57.1-not reached]) compared with the 45 Gy group (42.9 months [95% CI, 32.3-70.8]; HR, 1.76 [95% CI, 1.19-2.61]) and the 60 Gy group (38.0 months [95% CI, 30.8-51.9]; HR, 1.60 [95% CI, 1.05-2.44]) both before (P = .015) and after (P = .006) IPTW. Treatment-related toxicities were similar across the 3 groups. High-dose, accelerated, hyperfractionated, twice-daily thoracic radiation therapy (54 Gy) was well tolerated and effective in this large, real-world cohort study of patients with LS-SCLC compared with standard-dose (45 Gy twice daily and 60-70 Gy every day) radiation therapy.