The impact of tumor location on the biological and oncological differences of colon cancer: Multi-institutional propensity score-matched study.

Background: Several studies have reported some differences between right-sided and left-sided colon cancer. The aim was to analyze the differences in clinical and pathological features, recurrence, and prognostic impact of tumor location in patients with tumors truly located in the right and left side of the colon.

Patients: The study included 6790 stage I-III colon cancer patients who underwent curative resection. Patient characteristics were balanced using propensity score matching.

Results: Recurrence rates of stage I and II patients with left-sided colon cancer were higher than those in the right-sided group, indicating that recurrence free survival of left-sided colon cancer patients was significantly shorter than that of the right-sided patients. In stage III patients that experienced recurrence, cancer specific survival after recurrence of the right-sided colon cancer patients was significantly shorter than that of the left-sided patients (P = 0.003).

Conclusions: In stage I-II patients, left-sided colon cancer was a significant risk factor for recurrence free survival, however, in stage III patients, right-sided colon cancer was a significant risk factor for after recurrence cancer specific survival.