This study aims to evaluate whether resecting the primary tumor can improve the outcomes of treatment with sintilimab and chemotherapy in advanced EGFR/ALK-negative non-small cell lung cancer (NSCLC). Patients will be randomly assigned to one of two groups: one group will undergo primary tumor resection followed by sintilimab, pemetrexed, and carboplatin, while the other group will only receive sintilimab, pemetrexed, and carboplatin. The study will assess progression-free survival, overall survival, treatment response, safety, and the impact of treatment on quality of life. Through this study, we hope to determine whether primary tumor resection can provide additional benefits of anti-PD-1 therapy and chemotherapy for advanced NSCLC.