Primary tumor location in stage III colon cancer has prognostic impact on subsequent liver metastasis.

BACKGROUND AND

OBJECTIVES

We aim to investigate whether a difference exists between right-sided and left-sided colon cancer at the same disease stage and subsequent liver metastasis and identify whether tumor location can independently influence survival.

METHODS

Right-sided colon cancer was defined as malignancy arising from the cecum to the transverse colon; left-sided colon cancer was defined as malignancy arising from the splenic flexure to the sigmoid colon. Clinicopathological features and survival data were collected for analysis.

RESULTS

Overall, 1442 patients were included for analysis. The median follow-up time was 58.2 months. Patients with left-sided colon cancer had better 5-year overall survival (75.2% vs 61.7%, P = 0.005), 5-year cancer-specific survival (81.6% vs 73.4%, P = 0.001), and 5-year recurrence-free survival (70.9% vs 66.5%, P = 0.033) compared with patients having right-sided colon cancer. After the presentation of subsequent liver metastasis, patients with primary left-sided colon cancer had better 3-year cancer-specific survival ( P < 0.001). In the multivariate analysis, cancer location was an independent prognostic factor for cancer-specific survival (right vs left, HR: 1.276, 95% CI: 1.002-1.625).

CONCLUSIONS

The primary tumor location can serve as a prognostic factor for treatment outcomes either in primary stage III colon cancer or subsequent liver metastasis.