HE4 protein and SMRP: Potential novel biomarkers in ovarian cancer detection

Epithelial ovarian cancer has the highest mortality of all gynecological cancers, and its progression is often without symptoms. Clinical outcome and survival may be improved if the disease is identified in the early stages. The objective of the study was to evaluate the utility of the serum biomarkers human epididymis protein 4 (HE4), soluble mesothelin-related protein (SMRP) and CA125 in the detection of ovarian cancer. In this retrospective study, the serum concentrations of CA125, HE4 protein and SMRP were measured in a cohort of 70 patients with epithelial ovarian cancer (EOC) compared with 78 healthy controls. Median serum levels of CA125 for ovarian cancer cases were 503.55±560.7 U/ml vs. 9.28±14.47 U/ml in the control group (p<0.001); for SMRP 5.13±7.64 nM vs. 1.02±0.89 nM (p<0.01); and for HE4 597.95±934.59 pM vs. 56.75±43.79 pM (p<0.001), respectively. Positive correlations between the clinical stage of EOC and CA125, HE4 and SMRP serum concentrations were found [(R=0.83; p<0.001); (R=0.64; p<0.001); (R=0.45; p<0.001), respectively]. Data analysis for the whole study group also revealed a significant correlation between plasma concentrations of CA125 and HE4 (R=0.45; p<0.001), between CA125 and SMRP (R=0.38; p<0.001) as well as HE4 and SMRP (R=0.51; p<0.001). Similar significant correlations between serum biomarker concentrations were also found in the ovarian cancer group [CA125 and HE4 (R=0.31; p<0.01); CA125 and SMRP (R=0.25; p<0.05); HE4 and SMRP (R=0.44, p<0.001), respectively]. A significant correlation was observed between the serous histological type of EOC and serum concentration of HE4 in the study group compared with other non-serous types of ovarian cancer (p<0.01). In conclusion, measuring CA125 in combination with new biomarkers such as SMRP and HE4 may improve the accuracy of ovarian cancer diagnosis, particularly in early detection of the disease.