Serum human epididymis protein 4 levels in colorectal cancer patients.

Tumour markers are widely used for the diagnosis, staging and monitoring of colorectal cancer (CRC) patients in clinical practice. Carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) are the most frequently used biomarkers in CRC patients. A number of studies have recently investigated the presence of human epididymis protein 4 (HE4) overexpression in certain cancer types. Its significance in ovarian and endometrial cancer has been well-demonstrated. The aim of the present study was to evaluate the significance of serum HE4 levels in CRC patients. A total of 46 newly diagnosed CRC patients and 36 age- and gender-matched healthy subjects were included in the study. The concentrations of CEA and CA19-9 were also determined and compared according to HE4 levels. HE4 positivity was determined in 13 of the 46 cases (28.3%) in the CRC group, but no HE4-positive subjects were identified in the control group (0%; P=0.009). The area under the receiver operating characteristic curve for HE4 positivity was 0.641 (95% CI: 0.523-0.760). HE4 was statistically significantly positive in patients with stage III-IV disease and in those with high CA 19-9 levels (all P<0.01). To the best of our knowledge, this is the first study to investigate HE4 expression in CRC patients, and the findings suggest that it may be a useful biomarker, particularly in stage III-IV patients.