Real-World Outcomes of Radiation After Chemoimmunotherapy for Stage III Lung Cancer

Radiation following chemoimmunotherapy is not currently a standard treatment approach for Stage III non-small cell lung cancer (NSCLC). However, a need for this treatment scenario may arise in patients who underwent intended neoadjuvant chemoimmunotherapy but ultimately no resection. Here we evaluate the practice patterns and outcomes of radiation after chemoimmunotherapy as a nonsurgical option for stage III NSCLC patients.

Clinical Stage III NSCLC patients diagnosed between 2018 and 2022 who received chemoimmunotherapy followed by thoracic radiation (or chemoradiation) were identified in the National Cancer Database. Characteristics were compared by Chi-squared test to patients receiving chemoimmunotherapy alone, chemoradiation followed by immunotherapy, or chemoimmunotherapy followed by surgery. Three-year overall survival was described with Kaplan-Meier curves.

In total, 1293 stage III patients received chemoimmunotherapy followed by radiation, while 5382 received chemoradiotherapy followed by immunotherapy, 1921 received chemoimmunotherapy, and 745 received chemoimmunotherapy followed by surgery. Most (1145, 88.6%) chemoimmunotherapy followed by radiation patients received a total radiation dose of ≥ 54 Gy, and 90-day mortality after radiation was 5.3%. Chemoimmunotherapy followed by radiation patients were more often staged T4 (41.5% vs. 34.8%, P < .001) or N3 (26.2% vs. 20.5%, P < .001) compared to chemoradiation/immunotherapy. Three-year overall survival was 51.7%. For reference, 3-year overall survival was 37.3% for chemoimmunotherapy alone, 56.0% for chemoradiation/immunotherapy, and 81.5% for chemoimmunotherapy/surgery.

Radiation after chemoimmunotherapy appears to be a substantially utilized, safe, and potentially effective regimen for Stage III NSCLC. Further study is indicated to evaluate chemoimmunotherapy followed by radiation as an alternative nonsurgical option for clinical stage III patients.