Researchers at The University of Texas MD Anderson Cancer Center recently demonstrated that the protein CA-125, which is recognized for predicting ovarian cancer recurrence, could be used as a screening tool to detect early-stage ovarian cancer in post-menopausal women, even in the most aggressive forms. The findings are published in Cancer, and the preliminary data were first presented at the 2010 American Society of Clinical Oncology (ASCO) annual meeting.
“I and other scientists in the gynecologic oncology community thought we would ultimately find a better marker than CA-125 for the early detection of the disease,” said Karen Lu, MD, professor and chair, Department of Gynecologic Oncology and the study’s corresponding author. “After looking at new markers and testing them head-to-head in strong, scientific studies, we found no marker better than CA-125.”
For the prospective 11-year study, 4,051 women were enrolled from seven sites across the country and all of those participants were healthy, post-menopausal women, ages 50-74, with no strong family history of ovarian cancer. Each woman received a baseline CA-125 blood test using the Risk of Ovarian Cancer Algorithm (ROCA) to be grouped in three risk-levels; “low” came back in a year for a follow up blood test / “intermediate” repeated CA-125 blood test in three months / “high” received transvaginal sonography (TVS) and had checked by a gynecologic oncologist. Researchers examined how precisely the marker would work to detect ovarian cancer, and also how many times of operations are required.
As a result, the specificity of cancer detection was 99.9% and the screening failed to detect two borderline ovarian cancers, according to Lu. Of great importance is that the 4 invasive ovarian cancers detected were high-grade epithelial tumors that is the most aggressive form of the disease, and they were detected in early stage at IC or IIB that is treatable and often curable.
“CA-125 is shed by only 80 percent of ovarian cancers,” explained Bast, the study’s senior author. “At present, we are planning a second trial that will evaluate a panel with four blood tests including CA-125 to detect the cancers we may otherwise miss with CA-125 alone. The current strategy is not perfect, but it appears to be a promising first step.”
The video below provides an overview of the CA-125 biomarker: