New Screening Technique for Ovarian Cancer
Study Shows New Approach May Have Potential to Screen for Early-Stage Ovarian Cancer
For the new study, the researchers evaluated the "Risk of Ovarian Cancer Algorithm" (ROCA), based on a patient's age and changes in CA-125 blood levels results over time.
Women with the greatest change in CA-125 levels are referred for transvaginal sonography (TVS), and, when needed, to a gynecologic oncologist to determine if surgery is necessary.
The study included 3,238 postmenopausal women aged 50 to 74 without a family history of breast or ovarian cancer. They were followed for up to nine years.
On an annual basis, less than 1% of the women were categorized as high risk of ovarian cancer based on their change in CA-125 levels and referred for TVS.
About 7% of women were categorized as being at intermediate risk -- "their CA-125 levels went up slightly," Lu says -- and told to come back for CA-125 screening every three months.
"So over 90% of women were low risk and just had to come back for CA-125 screening annually," she says.
Of the 85 women categorized as high risk over the course of the study, eight went on to have surgery.
Three of the eight had early-stage aggressive ovarian cancers, "the kind that I as a doctor want to pick up early," Lu says.
"All three women with invasive ovarian cancers had at least three years of low-risk annual CA-125 values prior to a rising CA-125," she adds.
Two women had borderline ovarian tumors, two had benign ovarian tumors, and one had endometrial cancer.
A total of 99.9% of women categorized as being high risk based on the ROCA results did in fact have cancer, meaning that the rate of false-positives "is very, very low," Lu says.
The study also showed that based on ROCA results, no more than three operations were needed to detect one case of invasive ovarian cancer.
"Within the medical community, we feel like it should be no more than 10 operations to detect one case of invasive cancer, so this is within those parameters," Lu says.
There were not enough patients to determine the false-negative rate, Lu says.
The approach missed two borderline cases; however, no invasive ovarian cancers were missed.
"Could these borderline cases become invasive later? It's possible, but biologically, they tend to act differently," Lu says.