ROMA Index Calculator (Ovarian Malignancy Risk)
ROMA Index Calculator (Ovarian Malignancy Risk)
Combine HE4, CA 125 and menopausal status into a single risk estimate that guides referral for an adnexal mass.
ROMA Index (Ovarian Malignancy Risk)
Two-marker logistic indexHE4 70 pmol/L, CA 125 45 U/mL, postmenopausal
Formula
PI (postmenopausal) = −8.09 + 1.04·ln(HE4) + 0.732·ln(CA125)
ROMA (%) = e^PI ÷ (1 + e^PI) × 100
- HE4
- human epididymis protein 4, pmol/L
- CA125
- cancer antigen 125, U/mL
- PI
- predictive index — the logistic combination of the two markers, with different coefficients by menopausal status
Worked example
HE4 70 pmol/L, CA 125 45 U/mL, postmenopausal
PI = −8.09 + 1.04 × ln(70) + 0.732 × ln(45) = −8.09 + 4.418 + 2.786 = −0.885
ROMA = e^−0.885 ÷ (1 + e^−0.885) × 100 = 0.413 ÷ 1.413 × 100 = 29.2% ROMA
Just below the 29.9% postmenopausal high-risk cut-off
ROMA cut-offs by menopausal status
| Status | High-risk cut-off |
|---|---|
| Premenopausal | ≥ 11.4% |
| Postmenopausal | ≥ 29.9% |
What else raises CA 125
| Condition | Effect on CA 125 |
|---|---|
| Endometriosis | Raised, independent of malignancy |
| Uterine fibroids | Raised |
| Pregnancy, menstruation | Raised |
| Pelvic inflammatory disease | Raised |
| Cirrhosis, heart failure | Raised via peritoneal or pleural irritation |
What ROMA adds to CA 125 alone
ROMA combines HE4 and CA 125 with menopausal status to stratify a woman with an adnexal mass into low or high risk of epithelial ovarian cancer, and the result is used to guide referral to a gynaecological oncologist rather than to a general gynaecologist — a referral pathway shown to improve surgical outcomes.
The cut-offs differ by menopausal status — commonly 11.4% premenopausal and 29.9% postmenopausal — because baseline HE4 and CA 125 both shift with menopause. The band shown here uses the postmenopausal threshold; a premenopausal result must be read against 11.4%, not against this page’s default band, and using the wrong cut-off will misclassify a meaningful proportion of women.
CA 125 alone is raised by endometriosis, uterine fibroids, pregnancy, menstruation, pelvic inflammatory disease, cirrhosis and heart failure — conditions with nothing to do with malignancy — which is precisely why HE4 was added to the index. HE4 is much less affected by these benign gynaecological and inflammatory conditions, so combining the two markers cancels out a substantial source of false-positive risk that CA 125 alone would generate.
ROMA does not diagnose cancer and does not replace imaging or histology. It is a triage tool: a high result increases the probability that surgery should happen at a specialist centre, and a low result does not exclude malignancy outright.
Frequently asked questions
What does the ROMA index measure?
It combines HE4, CA 125 and menopausal status into a single percentage risk of epithelial ovarian cancer in a woman with an adnexal mass, used to guide referral to a gynaecological oncologist.
What ROMA cut-off should I use?
11.4% for premenopausal women and 29.9% for postmenopausal women. Using the postmenopausal cut-off on a premenopausal result will misclassify risk.
Why is HE4 combined with CA 125 rather than used alone?
CA 125 is raised by many benign conditions — endometriosis, fibroids, pregnancy, pelvic inflammatory disease, cirrhosis and heart failure. HE4 is far less affected by these, so combining the two reduces false positives.
Does a low ROMA score rule out ovarian cancer?
No. ROMA is a triage tool that stratifies risk to guide referral; it does not replace imaging or histological diagnosis, and a low score does not exclude malignancy.
Related calculators
References
- Moore RG et al. A novel multiple marker bioassay utilizing HE4 and CA125 for the prediction of ovarian cancer in patients with a pelvic mass. Gynecol Oncol. 2009;112(1):40–46.
- Moore RG et al. Utility of a novel serum tumor biomarker HE4 in patients with a pelvic mass. Am J Obstet Gynecol. 2008;198(3):351.e1–351.e11.