Persistence of epidermal growth factor receptor and interleukin 10 in blood of colorectal cancer patients after surgery identifies patients with high risk to relapse.

Abstract

Despite the great number of studies performed to detect circulating markers of disease progression in colorectal cancer, few have shown a clinical use; among those, epidermal growth factor receptor (EGFR) and, more recently, interleukin (IL)-10. In this article, we sought to investigate how primary surgery could affect expression levels of EGFR, IL-6, and IL-10 in blood from colorectal cancer patients. We investigated by reverse transcriptase-PCR assay the expression at mRNA level of EGFR, IL-6, and IL-10 in blood samples taken from 56 colorectal cancer patients. Each gene expression was evaluated 1 day before and 20 days after primary surgery. Persistence of each gene in blood after surgery was then correlated to the relapse free time in a follow-up of 3 years. In blood samples taken before surgery, EGFR, IL-6, and IL-10 were found expressed in 62, 100, and 100% of patients, respectively. EGFR expression, but not IL-6 and IL-10, correlates with stage of disease. In the group of 41 patients who underwent follow-up studies, EGFR was found persistently high in 67%; 94% of them had relapse. Persistence of IL-10 after surgery also identifies relapses in 89% of cases. IL-6 persistence was not found to significantly correlate to progression of disease. Persistence of both EGFR and IL-10 in blood of colorectal cancer patients after surgery identifies patients with high propensity to relapse. These findings may suggest a clinical use of preoperative EGFR/IL-10 reverse transcriptase-PCR assay in the prediction of tumor recurrence.