Radiotherapy to All Residual Lesions After Chemoimmunotherapy

Extensive-stage small-cell lung cancer is a lethal malignancy with an extremely poor prognosis. First-line chemotherapy could only achieve an overall survival of approximately 10 months. CREST study demonstrated that the addition of thoracic radiotherapy to the patients who responded to chemotherapy could increase the 2-year survival rate from 3% to 13%. CASPIAN and IMpower 133 trials have established the standard modality of first-line chemoimmunotherapy for extensive-stage small-cell lung cancer and prolonged the overall survival to 13 months. Both the addition of thoracic radiotherapy and immunotherapy to chemotherapy were able to improve the survival. Recently, several retrospective studies have demonstrated the effectiveness and safety of the combination of thoracic radiotherapy and chemoimmunotherapy. In a prospective study, 4-6 cycles of first-line chemotherapy with Adebrelimab followed by thoracic radiotherapy achieved the progression-free survival of 10.1 months and overall survival of 21.4 months, which was longer than chemoimmunotherapy. Another study demonstrated not only thoracic radiotherapy, but also radiotherapy to metastatic lesions could ameliorate survival. Therefore, we supposed that whether radiotherapy to all residual lesions after first-line chemoimmunotherapy could further improve survival for patients with extensive-stage small-cell lung cancer.