Efficacy and Mechanism of Combining Radiotherapy and Immunotherapy in Stage IV Non-Small Cell Lung Cancer

Lung cancer is the leading cause of cancer-related deaths worldwide, with about 85% of patients being diagnosed as non-small cell lung cancer (NSCLC); and most presenting with stage IV disease initially. With the continuous advancement of treatment strategies of oncology, immunotherapy with/without chemo-immunotherapy has become the first-line treatment for patients with stage IV NSCLC. However, a proportion of patients still develop resistance to the treatment regimen and experience local progression, and primary lung lesion progression is the main progression pattern of stage IV NSCLC. Preclinical and clinical studies have demonstrated the potential of radiotherapy in anti-tumor treatment and suggest that administering local radiotherapy prior to cancer progression can prolong survival. Therefore, we consider whether adding local radiotherapy before the progression of a pulmonary lesion in stage IV NSCLC patients receiving chemo-immunotherapy would be beneficial. The present review aims to explore the efficacy and safety of combining radiotherapy with immunotherapy in the treatment of stage IV NSCLC, delving into the intricacies of their underlying mechanism.