Upregulation of Fecal Cytokeratin 19 Is Associated with Prognosis in Older Colorectal Cancer Patients

Abstract

The upregulation of fecal cytokeratin 19 (CK19) correlates with age and metastatic status in human colorectal cancer (CRC). To further explore its clinical significance in older patients (>60 years), their fecal CK19 was measured by quantitative reverse transcription-polymerase chain reaction. Differences in CK19 transcripts were compared using the nonparametric Mann-Whitney U test. Clinical significance was assessed with the chi-squared test and a binary logistic regression model. The association between overall survival and expressions of fecal CK19 in combination with other serum markers, carcinoembryonic antigen and carbohydrate antigen 19-9 (CA19-9), was evaluated using the Kaplan-Meier method. In these older groups, CRC patients had significantly higher median fecal CK19 expression (p = 0.006) than controls. The highest risk of CRC (odds ratio, 5.8; 95% confidence interval, 2.3-14.7; p < 0.001) was detected when the cutoff value for fecal CK19 expression was set at the median value of the 28 healthy controls. The lowest overall survival (29.2% ± 21.4%) occurred in patients in whom serum CA19-9 levels were high and fecal CK19 was overexpressed. Our results suggest that fecal CK19 expression is associated with CRC, and together with serum carcinoembryonic antigen or CA19-9, it can predict overall survival in older patients.