Prognostic factors for locoregional recurrences in colon cancer

There is increased interest in locoregional recurrences of rectal cancer. Despite comparable locoregional recurrence rates in colon cancer, only a few studies on locoregional recurrences among colon cancer patients have been published. This study was designed to identify prognostic factors for locoregional recurrences among patients with colon cancer in the Netherlands.

The study population was composed of patients who underwent radical surgical resections for invasive colon carcinoma, diagnosed in three regions of the Netherlands from 2000 to 2003. The Kaplan-Meier method was used to calculate 5-year locoregional recurrence rates (LRR). Conditional hazard rates were estimated by the life-table method. Multivariate Cox regression analyses were performed to identify prognostic factors and to calculate a Locoregional Recurrence Risk Score (LRRS).

In total 127 of 2,282 patients developed locoregional recurrences within 5 years (LRR 6.4%). The risk of developing a locoregional recurrence was highest at 0.5-1 year after surgery. Patients with left-sided tumors, T3-T4 tumors, and positive lymph nodes and those who did not receive adjuvant chemotherapy were more likely to develop locoregional recurrences. Four risk groups based on the LRRS were defined. Five-year LRR was 2.5% for the very low-risk group and 25.1% for the high-risk group.

Although the locoregional recurrence rate in this study was relatively low, it remains a considerable problem. Identifying individual patients who might benefit from adjuvant chemotherapy may reduce the locoregional recurrence rate.