Adjuvant chemotherapy with or without targeted therapy for patients with resectable synchronous colon cancer and liver or lung-confined metastases: a nationwide Taiwanese database study.

BACKGROUND: The efficacy of targeted therapies in patients with resectable synchronous colon cancer and liver- or lung-confined metastasis (SCCLM) following curative surgery remains unclear. PATIENTS AND METHODS: A population-based cohort of patients with de novo SCCLM diagnosed between 2014 and 2022 was established using data from the Taiwan Cancer Registry and the National Health Insurance Research Database of Taiwan. Patients who underwent curative surgery as initial therapy, followed by chemotherapy doublets with or without targeted therapy, were included, and treatment outcomes were assessed. RESULTS: A total of 804 patients were included in the analysis. RAS wild-type tumors and left-sided primary colon tumors were identified in 375 (46.6%) and 459 (57.1%) patients, respectively. The liver was the metastatic site in 88.1% of cases. Targeted therapy was administered to 561 (69.8%) patients. Compared with patients receiving chemotherapy alone, those receiving targeted therapy plus chemotherapy had shorter overall survival (OS; median: 3.85 versus 5.24 years, P < 0.001). In the multivariate analysis, the use of targeted therapy was associated with significantly worse OS among patients with left-sided colon cancer [hazard ratio (HR) 1.72, 95% CI 1.07-2.79, P = 0.026] but not among those with right-sided disease (HR 0.81, 95% CI 0.51-1.27, P = 0.357). Regardless of tumor sidedness, targeted therapy was not an independent predictor of time to treatment failure (TTF). CONCLUSIONS: The addition of targeted therapies to adjuvant chemotherapy following curative surgery in patients with SCCLM did not improve OS or TTF. This finding suggests that adjuvant chemotherapy alone may be the preferred therapeutic approach in this patient population.