HE4 immunohistochemical expression in serous carcinomas of the ovary and uterus: A pathological guide to primary site determination

Background Uterine serous carcinoma and high-grade serous ovarian cancer exhibit identical morphological characteristics, irrespective of their site of origin, necessitating an immunohistochemical marker to ascertain tumor origin. Human epididymis protein (HE4) is variably expressed in endometrial and ovarian carcinomas. This study seeks to evaluate the significance of HE4 in identifying the anatomical origin of malignancies by contrasting its expression levels between the two tumor types. Results In 14 out of 20 cases of uterine serous carcinoma and in 22 out of 30 cases of ovarian serous carcinoma, HE4 tissue immunoexpression was found. The frequency of HE4 immunostaining expression was insignificant between the two groups (uterine and ovarian serous carcinoma) ( P =0.956). HE4 expression and tumor staging in the studied cases showed a significant statistical relation. Conclusion These data indicate no significant relation between HE4 expression and tumor origin, which makes the value of HE4 in recognizing tumor origin doubtful. Based on long-term follow-up, larger studies including a larger number of patients are required.