"So, similar to pancreatic cancer, it's a disease where it's often caught in late stages when cure is very difficult. So there's clearly a need to find a way to detect ovarian cancer in its earliest stages."
Dr. Lu's study looked at a protein called CA-125. Women with ovarian cancer will often have this biomarker floating around in their bloodstream. Although scientists have known about CA-125 for two decades, they didn't think it would work as a screening test for a few reasons. One is that the biomarker only shows up in about half of women who have early-stage ovarian cancer.
"The other problem was that a number of regular gyn, regular female conditions will elevate it, so fibroids, endometriosis, pelvic infections, any of those things can falsely elevate it."
The nine-year study tried a new approach. More than 3,000 women over age 50 had the blood test once a year, and researchers watched their levels of CA-125 over time. An algorithm would alert doctors if the level rose suddenly after years of steadiness. Some women came back for another test in three months, and others had an ultrasound to see if they needed exploratory surgery.
"Instead of looking at a single value, it looks at the change over time. So each woman essentially creates their own baseline."
This system had positive results: early-stage ovarian cancer was found in five women who had no symptoms, and there weren't a lot of false positives. Lu cautioned that it's too early to make this a standard part of the annual gynecologic exam.
"There's an ongoing study in the United Kingdom that's testing almost exactly the same algorithm that includes 200,000 women. So a very, very large study. And we'll have results in about 4-5 years to let us know whether doing this screening strategy will decrease mortality from ovarian cancer, which is considered the gold standard for any type of screening study."
The blood test costs $125. Lu and her colleagues will continue the study, looking for additional biomarkers and seeing if a finger-prick would work as well as a blood draw. For information on enrolling in the study, call (877) 632-6789.
In addition to Lu, and Bast, other authors on the study include: Theresa Bevers, M.D. Department of Clinical Cancer Prevention, Herbert Fritsche, Ph.D., Department of Laboratory Medicine, and Deepak Bedi, M.D., Department of Diagnostic Radiology, all with MD Anderson; Steven Skates, Ph.D., Massachusetts General Hospital and Harvard Medical School; Olasunkanmi Adeyinka, M.D., UT Physicians Family Medicine Center; William Newland, M.D., The Iowa Clinic; Richard Moore, M.D., Women & Infants Hospital of Rhode Island and The Warren Alpert Medical School of Brown University; Leroy Leeds, M.D., The Women's Hospital of Texas; and Steven Harris, M.D., Baylor University Medical Center at Dallas.