NE-4 (ovaries)
NE4 (Human epididymis protein 4) – an oncomarker, which is used for screening diagnosis and monitoring the effectiveness of treatment of ovarian tumors. The literal translation of the name of the test is "human testicular appendage protein", this is due to the fact that for the first time the protein was found in the appendages of the testicles in men. Subsequently, it was possible to identify the protein in some other tissues of the body, including the lungs. However, NE4 found its application in oncology after the discovery of the property of the protein to be produced in large quantities in the cells of epithelial ovarian carcinoma. Consequently, with this pathology, the total level of this protein in the patient's blood also increases.
Oncomarkers are various proteins that may normally be present in a healthy body, but their concentration increases dramatically in oncological diseases. Previously, CA-125 was used as an oncomarker for ovarian cancer screening. But this test has its own disadvantage: while it has an adequate level of sensitivity, it has a low level of specificity with respect to the exact location of the tumor. That is, CA-125 can tell that there is a tumor in the body, but is not able to be as precise as possible about which organ it is in.
Numerous analyses have been conducted to compare the sensitivity and specificity of HE4 and CA-125 in patients with various forms of benign and malignant pelvic neoplasms. All scientific papers provided different percentage data from each other, but the conclusion remained unchanged: NE4, in comparison with CA-125, has a higher sensitivity and specificity for the diagnosis of pelvic tumor diseases; CA-125 may be elevated in some other cancerous diseases in which the level of NE4 does not change. Thus, in order to maximize the reliability of preventive examinations, the use of these two tests simultaneously is recommended.
The only exception is the rare mucinous form of ovarian cancer, in which the activity in the blood of both NE4 and CA-125 does not increase. Like all oncomarkers, NE4 is a screening analysis, that is, a publicly available and cheap method that provides grounds for detailed instrumental examinations of an organ or organ system belonging to the cancer risk group. In other words, the results of the HE4 test alone are not a reason to confirm or exclude the diagnosis, but it plays an important role in the initial stage of ovarian cancer diagnosis.
If a woman is diagnosed with a mass in the pelvis by imaging, the ROMA (Risk of Ovarian Malignancy Algorithm) algorithm is used to determine the risk of the mass being cancerous. The algorithm takes into account the concentration of NE4 and CA-125 in the blood, as well as the menopausal status of the patient. Taking into account these data, ROMA indicates the degree of risk of malignancy of the neoplasm.
A false-positive result of the test is observed in the presence of kidney pathology in the patient (chronic kidney disease), due to impaired excretory function of the organ and, as a consequence, a natural increase in the blood physiological HE4.
Read also: "What oncomarkers can tell you", "Women's cancer profile", "10 main cancer symptoms worth knowing about"