Comparative effectiveness of primary tumor resection versus chemotherapy in patients with asymptomatic unresectable metastatic colorectal cancer: a retrospective cohort study using the target trial emulation framework.

Patients who undergo primary tumor resection (PTR) reportedly have significantly higher overall survival (OS) than those who do not undergo this procedure. However, this result is only evident in past retrospective studies, and clinical trial results did not show the same trend. Thus, it remains unclear whether primary tumor resection effectively increases survival in patients with metastatic colorectal cancer (mCRC) across different study designs.