Correlation of Human Epididymis Protein 4 Expression with Clinicopathologic Parameters in Gastric Carcinomas

Background: Human epididymis protein 4 (HE4) was discovered in 1991 as a glycoprotein secreted from the cells of the human epididymal epithelium and associated with sperm development and immunity. Subsequent studies have shown that HE4 is also expressed in many normal tissues such as reproductive, respiratory, and digestive tract epithelia. Although the mechanism of action of HE4 in cancers is still unknown, its increased expression has been reported in many tumors, especially gynecologic malignancies. In our study, we have investigated the relationship between gastric carcinomas and increased HE4 expression. Materials and Methods: HE4 expression was studied in 114 formalin-fixed paraffin-embedded gastric carcinoma specimens and its association with different clinicopathologic parameters was evaluated. Results: Immunohistochemical HE4 expression was strong in 88 patients and weak in 26 of 114 patients. A significant correlation was found between HE4 staining intensities and five-year survival rates (p=0.002). There was no significant correlation between HE4 staining intensity and human epidermal growth factor 2 (HER2)/neu amplification, as well as other clinicopathologic data. Conclusion: This study has demonstrated the association of HE4 expression with 5-year survival in gastric tumors. In addition, although no significant correlation was found between HE4 staining intensity and HER2/neu amplification in our study, a significant correlation between these parameters has been reported in the literature. In conclusion, HE4, which we have found to be associated with long-term survival in our study, can be used as a prognostic marker in gastric cancers.