Pattern of Tissue Expression of CA-125 and HE4 in Primary Epithelial Ovarian Tumours and Correlation with Serum CA-125 Levels

The objective of this study is to assess tissue expression of CA-125 and HE4 protein in primary benign andmalignant epithelial tumours of the ovary and correlate with serum CA-125 levels. A total of 100 formalin-fixed,paraffin embedded sections of ovarian tumours which included serous adenoma (11), mucinous adenoma (42),serous carcinoma (20), mucinous carcinoma (12) and endometrioid carcinoma (15), histologically diagnosedbetween 1st January 2004 to 31st December 2012 at the University Malaya Medical Centre, were stained for HE4(rabbit polyclonal antibody, Abcam, UK) and CA-125 (mouse monoclonal antibody clone: OC125, Cell MarqueCorporation, Rocklin, California, USA). Pre-operative serum CA-125 levels were obtained from the laboratoryinformation system. Immunoscore (I score) for HE4 and CA-125 was given based on the intensity of staining andpercentage of positive tumour cells and considered significant when it was >50 (intensity of staining multiplied bypercentage of positive tumour cells). Serum CA-125 levels were compared with the I score of HE4 and CA-125in tissues. We noted that the CA-125 levels in serum and tissues were significantly raised in malignant comparedto benign ovarian tumours (p value<0.05). Tissue expression of HE4 protein was also significantly raised inmalignant tumours compared to benign tumours (p value<0.05). We conclude that HE4 can be a useful tissueimmunomarker in addition to CA-125.