Whereas the RMI is largely based on ultrasound findings, the model that uses HE4 and CA125 – the Risk of Ovarian Malignancy Algorithm (ROMA) –“can be used to classify both postmenopausal and premenopausal women into high- and low-risk groups,” the researchers say in a May 17th article published online in the American Journal of Obstetrics and Gynecology.
The RMI is a popular tool for differentiating malignant pelvic masses from benign ones. It produces a numeric score to stratify patients into high- and low-risk groups for epithelial ovarian cancer based on ultrasound imaging data, which are “subject to interpreter variability between users and centers,” the investigators note.
“Equally important,” they add, clinical evaluation of a pelvic mass often includes CT imaging, MRI, ultrasound or a combination of imaging modalities, “resulting in a lack of standardization across imaging methods for risk of ovarian malignancy.”
Dr. Richard G. Moore from the Program in Women’s Oncology, Women & Infants Hospital of Rhode Island in Providence and colleagues developed the ROMA as an objective risk-assessment tool for epithelial ovarian cancer. Their study population comprised 457 women (212 premenopausal, 245 postmenopausal) with evaluable imaging results from ultrasound, CT, and MRI, as well as preoperative serum HE4 and CA125 levels.
The RMI incorporated CA125, imaging, and menopausal status, whereas ROMA was based only on HE4 and CA125 and menopausal status.
The 457 women had 123 epithelial tumors (17 stage I, 17 stage II, 80 stage III, 6 stage IV, and 3 unstaged), 22 low malignant potential tumors, and 312 benign masses.
The investigators report that at a set specificity of 75%, ROMA was significantly more sensitive than RMI for distinguishing benign status from epithelial cancer (94.3% vs 84.6%; p = 0.0029). In patients with stage I and II disease, ROMA achieved a sensitivity of 85.3% compared with 64.7% for RMI (p < 0.0001). The sensitivity for stage III and IV tumors was 98.8% for the ROMA and 93.0% for the RMI (p = 0.0350).
For benign cases versus all stages of low malignant potential tumors plus all stages of epithelial cancer, the ROMA had a sensitivity of 89.0% and the RMI had a sensitivity of 80.7% (p = 0.0113).
"Accurate triage and referral of women with a pelvic mass to appropriate surgeons and institutions will result in improved care for all women ultimately diagnosed with an epithelial ovarian cancer,” Dr. Moore and colleagues note in their report. “As well, an effective triage tool will allow women at low risk for malignancy to stay in their community to receive treatment from their primary gynecologist or surgeon.”
The ROMA could be a valuable “addition to the ACOG and SGO recommendations for referral to gynecologic oncologists, along with good clinical judgment,” Dr. Moore added in a telephone interview with Reuters Health.
Am J Obstet Gynecol 2010.