A new marker for breast cancer diagnosis, human epididymis protein 4: A preliminary study.

Breast cancer is the most frequently diagnosed cancer type in women. Tumor markers have been widely used for assessing the treatment response and early diagnosis of recurrence. Human epididymis protein 4 (HE4) is expressed in ductal carcinoma of the breast tissue; however, its serum levels and their diagnostic and prognostic potential in breast cancer have not been investigated, which was therefore the aim of the present study. The serum levels of HE4 were determined in 36 breast cancer patients, 11 ovarian cancer patients and 16 healthy volunteers. The association between clinicopathological characteristics of breast cancer and serum HE4 levels was investigated. A significant difference in the median serum levels of HE4 was identified between breast cancer patients, ovarian cancer patients and healthy volunteers (P=0.013). The cutoff value for the prediction of breast cancer was determined at >13.24 pmol/l for HE4, with a sensitivity of 61.11%, specificity of 68.75%, positive predictive value of 81.48%, negative predictive value of 44.0% and accuracy of 63.46%. Furthermore, a positive correlation between the serum levels of HE4 and cancer antigen 15-3 was determined (r=0.399, P=0.026). To the best of our knowledge, the present study was the first to determine the diagnostic value of serum HE4 for breast cancer. A significant elevation of serum HE4 levels in patients with breast cancer compared with that in healthy controls was identified. HE4 may serve as a novel biomarker for the diagnosis of breast cancer.