Headline: Does thoracic radiation improve survival for extensive stage SCLC in the immunotherapy era?
The Study: In the pre-immunotherapy era, the CREST trial found that thoracic radiation improved survival in select patients who responded to initial systemic therapy. This phase 3 trial included 228 patients with ES-SCLC who received carbo/etoposide and durvalumab who were randomized to receive thoracic RT (30 Gy in 10 fractions) or not during chemoimmunotherapy. Note that this trial selected patients relatively early in treatment and started radiation early in treatment as well. The trial was discontinued early due to increased adverse effects with RT and futility. The primary endpoint of overall survival was not significantly longer with thoracic RT (10 v 11.1 months). This may have been driven by a higher rate of death from other causes in the RT arm (14.8% v 3.5%). However, many of these happened before RT even started and there was no difference in noncancer deaths when these cases were omitted (9.6% v 3.5%). PFS was also similar between groups (5.1 v 5.1 months). While the rate of any AEs was higher with RT (87.8% v 69.9%), the rate of grade 3+ AEs was similar (21.1% v 17.5%). Grade 3+ esophagitis was significantly higher with RT (47.8% v 10.4%).
TBL: In this randomized trial, early thoracic RT did not significantly improve median overall survival in patients who received chemoimmunotherapy for ES-SCLC. | Gronberg, ASCO 2026
The Study: In the pre-immunotherapy era, the CREST trial found that thoracic radiation improved survival in select patients who responded to initial systemic therapy. This phase 3 trial included 228 patients with ES-SCLC who received carbo/etoposide and durvalumab who were randomized to receive thoracic RT (30 Gy in 10 fractions) or not during chemoimmunotherapy. Note that this trial selected patients relatively early in treatment and started radiation early in treatment as well. The trial was discontinued early due to increased adverse effects with RT and futility. The primary endpoint of overall survival was not significantly longer with thoracic RT (10 v 11.1 months). This may have been driven by a higher rate of death from other causes in the RT arm (14.8% v 3.5%). However, many of these happened before RT even started and there was no difference in noncancer deaths when these cases were omitted (9.6% v 3.5%). PFS was also similar between groups (5.1 v 5.1 months). While the rate of any AEs was higher with RT (87.8% v 69.9%), the rate of grade 3+ AEs was similar (21.1% v 17.5%). Grade 3+ esophagitis was significantly higher with RT (47.8% v 10.4%).
TBL: In this randomized trial, early thoracic RT did not significantly improve median overall survival in patients who received chemoimmunotherapy for ES-SCLC. | Gronberg, ASCO 2026