Is CA-125 a Good Marker for Understanding Your Ovarian Cancer Risk?June 24, 2016
This article was originally published on SheKnows.
With nearly 22,000 new cases expected in 2015, ovarian cancer is one of the most frightening possibilities women can face — especially considering that the majority carry at least one risk factor.
While the key to successful cancer treatment is early detection, ovarian cancer is one of the most difficult diseases to discover early.
Women often don’t experience symptoms until a tumor develops or the disease reaches its later stages. In fact, according to the American Society of Clinical Oncology, 70 percent of epithelial ovarian cancers, the most common form, aren’t found until they’ve spread.
The major reason is the use of antiquated diagnostics. In the past 30 to 40 years, ovarian cancer detection and survival rates have not improved.
Often, family history is the best indicator of risk. Talk to your doctor about your risk factors and concerns to decide which options best fit your needs.
Screening for Ovarian Cancer
Tests can help detect ovarian cancer if it’s present, but no current screening method is adequate for women without symptoms. Common screenings include a blood test for cancer antigen 125, known as CA-125, and an ultrasound.
CA-125 is a protein produced on the surface of cancer cells, and the screening gauges the amount of it in the blood. CA-125 is used to detect tumors because it’s usually found in higher quantities in women with ovarian cancer, but the test isn’t foolproof because many other noncancerous conditions — such as menstruation, endometriosis, or even the first trimester of pregnancy — can increase the levels. Similarly, low CA-125 doesn’t necessarily mean a patient is cancer-free.
Studies have found that 20 percent of ovarian cancer patients do not show any increase in CA-125 concentrations. CA-125 is most likely to be high in women with advanced ovarian cancer, but during early-stage cancer, a woman’s CA-125 is still in the normal range up to 50 percent of the time. That means the CA-125 test isn’t an adequate early detection tool by itself; instead, it’s best for monitoring cancers during and after treatment to determine success.
Though CA-125 isn’t an effective early detection tool, women who have never had ovarian cancer and don’t have family histories of the disease can try other screening options. Ultrasound scans, which use high-frequency sound waves to create images, might show cysts or swellings in concerning ovaries. Studies have shown, though, that CA-125 tests and transvaginal ultrasounds don’t result in a decrease in ovarian cancer deaths.
If CA-125 tests alone or with an ultrasound are not effective, what new technologies are? Your doctor may use one of the new available tests after an ultrasound if she is concerned about your risk. They include:
• OVA1. This recently approved test involves examining five biomarker proteins in the blood and using those results with an algorithm to determine the probability of ovarian cancer being present. Studies have shown that OVA1 can find ovarian cancer at all ages and stages and can indicate risk in all types of ovarian cancer for both premenopausal and postmenopausal women.
• HE4. HE4 is another protein used to monitor the progression of ovarian cancer and to also detect ovarian cancer. Studies from the Mayo Medical Laboratories have shown that an HE4 test can be more effective for detecting certain types of ovarian cancer than CA-125.
No option is foolproof, but an awareness of ovarian cancer risk — coupled with an eagerness to get tested — offers the best outcomes. Early detection at stage one equals 90 percent survival, but at stage three, the odds fall to a maximum of 20 percent. How do you want your chances to stack up?
Dr. Judy Wolf is the chief medical officer at Vermillion. She received her medical degree from the Northeast Ohio Medical University College of Medicine, and her clinical and research interests are in gynecologic cancers — specifically ovarian cancer.