ROMA index – calculation of the risk of ovarian cancer (CA-125, HE-4)
Why this test?
To determine the risks of a woman with a tumor in the small pelvis and assign her to a group of high or low risk of developing ovarian cancer.
In what cases is it prescribed?
When a suspicious mass in the pelvis is detected during a clinical examination or as a result of ultrasound or other diagnostic method.
Differential diagnosis of benign and malignant tumors of the ovary is one of the most difficult tasks of modern gynecology. On the one hand, surgical intervention and ovarian biopsy is the only reliable method to exclude ovarian cancer, on the other hand, biopsy cannot be routinely performed on all patients who have ovarian neoplasms, as they are very common and in most cases are benign (abscesses, adenomas, endometrioid cysts). In order to carry out the primary differential diagnosis of benign and malignant tumors of the ovary, American scientists have developed the ROMA algorithm (Risk of Ovarian Malignancy Algorithm), which allows to determine for patients high and low risk of developing ovarian cancer. To date, this algorithm has been tested in several large studies.
The ROMA algorithm is a mathematical model that calculates the probability of ovarian cancer at certain values of CA-125 and HE 4 tumor markers, taking into account the menopausal status of the patient. When developing the ROMA algorithm, the role of 7 ovarian cancer tumor markers was initially evaluated, but it was shown that the use of a combination of only two of them (CA 125 and HE 4) has the maximum prognostic value.
CA 125 is the most well studied tumor marker of ovarian tumors. It is a glycoprotein detected in almost all organs and tissues arising from the integumentary epithelium. CA 125 is normally present in small amounts in the blood. Increased concentration of CA 125 is observed in 80-92% of cases of advanced ovarian cancer. The sensitivity of CA 125 for early-stage ovarian cancer is low (30-50%), so this tumor marker cannot be used alone as a screening test.
HE4 (epididymal secretory protein) is a relatively new tumor marker for ovarian cancer. HE4 is a protease inhibitor that is normally present in the epithelium of the respiratory and reproductive system. Its level is elevated in the blood of women with ovarian cancer compared to women with normal ovaries or benign and highly differentiated ovarian malignancies. It is believed that HE 4 is more effective than CA 125 in detecting ovarian cancer. It should be noted, however, that the HE4 tumor marker, as well as the CA 125 tumor marker, is able to detect only malignant ovarian tumors of epithelial origin and does not detect germ cell tumors or tumors of the stroma of the spermatic cord (hormonally active).
When using the levels of these two tumor markers in the ROMA mathematical formula, taking into account the menopausal status of the patient, the probability of ovarian cancer is obtained, for example, 79.6% or 9.1%. The interpretation of the result depends on the menopausal status of the patient.
It should be noted that the ROMA algorithm is designed to assess the risk of ovarian malignancies of epithelial origin only (in English literature - epithelial ovarian cancer, in domestic sources - ovarian cancer and sometimes epithelial ovarian cancer). The ROMA algorithm is not intended to assess the risk of ovarian tumors of non-epithelial origin.
The test is prescribed to women who have a mass in the pelvis during a clinical examination or according to ultrasound or other diagnostic methods. If a mass in the pelvis is not detected, the ROMA calculation is not applied.
The ROMA algorithm allows to avoid unnecessary referral of a patient to an oncogynecologist and unnecessary laparoscopy with biopsy. It is, however, not a definitive method of diagnosis, but only a way to preliminarily distribute women into risk groups.