What is ovarian tumor marker testing?

Ovarian tumors are common gynecological tumors in women, but the symptoms are not very obvious in the early stages, so they pose a great threat to women's health. There are many types of tumor markers for ovarian cancer, but many people are not very clear about them, such as CA125, HE4, etc. Let’s take a look at what they are!

1. CA125

It was detected by Bast et al. from epithelial ovarian cancer in 1981. It is a glycoprotein that can bind to the monoclonal antibody OC125, has a molecular weight of 200Kd, and contains 24% carbohydrates. The serum CA125 level in healthy people is very low, and the upper limit of serum CA125 concentration in healthy adults is 35kU/L.

CA125 is an important ovarian cancer-related antigen and should not be used for screening. However, it can be combined with transvaginal pelvic ultrasound or other markers to improve the specificity of early screening. CA125 can be used to differentiate between benign and malignant ovarian masses. CA125>95 kU/L in postmenopausal women has a positive predictive value of 95%. In addition, CA125 is a good indicator for observing the efficacy and judging the presence or absence of recurrence. After the first chemotherapy cycle, if the CA125 level can drop to 1/10 of the original level, it indicates a good outcome. Continuous increase in CA125 levels during the first treatment indicates a poor prognosis. It is recommended to test once every 2 to 4 months for 2 years, after which the frequency of testing can be gradually reduced.

2. HE4

HE4 is a secretory glycoprotein discovered by Kirchhoff et al. in 1991 in the epididymal epithelial tissue. It belongs to the protease inhibitor WFDC gene family and contains four disulfide bond core regions composed of eight cysteines. The content of HE4 is low in benign tumors and normal tissues. Its high expression is often seen in ovarian cancer and endometrial cancer. The serum HE4 concentration of healthy adults is <150 pmol/L. HE4 has certain advantages in the early diagnosis of ovarian cancer. The sensitivity and specificity of a single test are 72.9% and 95%, respectively. Its value in the differential diagnosis of benign and malignant ovarian tumors is better than CA125, and it has been used for treatment monitoring of ovarian cancer patients in some areas.

3. Human chorionic gonadotropin (HCG)

HCG is a tumor marker for choriocarcinoma and malignant hydatidiform mole, and can also be seen in certain germ cell tumors. About 84% of ovarian cancer patients can see elevated HCG, which can be used to predict the prognosis of ovarian cancer. The 5-year survival rate of ovarian cancer patients with normal serum HCG can be as high as 80%, while the 5-year survival rate of patients with elevated serum HCG is only 22%.

4. Kallikrein family proteins

Kallikrein family proteins are a subgroup of the serine protease family and play an important role in tumor metastasis and prognosis. Kallikreins 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, and 15 have certain value in the diagnosis, prognosis, prevention, and monitoring of ovarian cancer. For example, kallikrein 4 is expressed primarily in serous tumors and is absent in normal ovarian epithelial cells. Its expression was associated with higher clinical stage and tumor grade, and a univariate survival analysis indicated that kallikrein 4 expression was associated with an increased risk of ovarian cancer recurrence and death.