Top Line: Does thoracic radiation improve survival in the context of immunotherapy for extensive stage small cell lung cancer?
The Study: Three randomized trials have evaluated consolidative thoracic RT in ES-SCLC using chemotherapy as the backbone. The Jeremic study found improved OS with thoracic RT, the CREST trial found a delayed improvement in OS at 2 years (but not the primary endpoint of 1 year OS), and RTOG 0937 showed improved time to progression but no improvement in OS. Now, immunotherapy is a standard part of systemic therapy for ES-SCLC. TREASURE was a randomized phase 2 trial of 68 patients with ES-SCLC who had at least stable disease after induction chemoimmunotherapy. They were randomized to receive maintenance immunotherapy with or without 30 Gy in 10 fractions thoracic RT. Baseline brain mets were present in 23.5%, and only 2.9% received PCI. The trial was stopped early due to safety concerns as the thoracic RT arm had a higher rate of severe adverse events (61.3% v 18.2%) and fatal events (19.4% v 3%, though several were deemed unrelated to treatment). Median PFS was similar between arms (2.4 v 2.6 months), while median OS was numerically shorter (6.7 v 13.4 months). The authors hypothesize (or some may say jump to conclusions) that prolonged lymphopenia after thoracic RT may have increased infection risk. However, neutrophils and leukocytes were similar between arms, and there’s no clear explanation why this would happen mainly in the context of immunotherapy.
TBL: TREASURE was stopped early due to a higher rate of severe adverse events with thoracic RT in patients receiving maintenance immunotherapy for ES-SCLC. | Bozorgmehr, JAMA Oncol 2026
The Study: Three randomized trials have evaluated consolidative thoracic RT in ES-SCLC using chemotherapy as the backbone. The Jeremic study found improved OS with thoracic RT, the CREST trial found a delayed improvement in OS at 2 years (but not the primary endpoint of 1 year OS), and RTOG 0937 showed improved time to progression but no improvement in OS. Now, immunotherapy is a standard part of systemic therapy for ES-SCLC. TREASURE was a randomized phase 2 trial of 68 patients with ES-SCLC who had at least stable disease after induction chemoimmunotherapy. They were randomized to receive maintenance immunotherapy with or without 30 Gy in 10 fractions thoracic RT. Baseline brain mets were present in 23.5%, and only 2.9% received PCI. The trial was stopped early due to safety concerns as the thoracic RT arm had a higher rate of severe adverse events (61.3% v 18.2%) and fatal events (19.4% v 3%, though several were deemed unrelated to treatment). Median PFS was similar between arms (2.4 v 2.6 months), while median OS was numerically shorter (6.7 v 13.4 months). The authors hypothesize (or some may say jump to conclusions) that prolonged lymphopenia after thoracic RT may have increased infection risk. However, neutrophils and leukocytes were similar between arms, and there’s no clear explanation why this would happen mainly in the context of immunotherapy.
TBL: TREASURE was stopped early due to a higher rate of severe adverse events with thoracic RT in patients receiving maintenance immunotherapy for ES-SCLC. | Bozorgmehr, JAMA Oncol 2026