New Ovarian Cancer Test Looks Promising
Ovarian cancer is a difficult cancer to test for because of its low prevalence and the fact that there are no symptoms in the early stages. Now researchers report promising results related to their initial work on a new test for ovarian cancer.
An estimated 21,880 new cases of ovarian cancer are expected in the United States in 2010, according to the National Cancer Institute, with 13,850 women dying of the disease. There are more than 30 different types and subtypes of ovarian cancer, with ovarian epithelial being the most common type.
Screening for the disease is still being studied, so clinicians must depend on current testing procedures, which lack accuracy, to detect the disease. A pelvic exam typically reveals ovarian cancer only once it has reached an advanced stage. Transvaginal ultrasound can detect cancerous lesions before they can be felt, but this costly method does not have high enough specificity and sensitivity to significantly reduce death in the general population. The CA-125 test measures the level of a substance that is released by cells into the blood, and so an elevated CA-125 level may be a sign of some types of cancer, including ovarian cancer, or other conditions.
New Ovarian Cancer Test
The new ovarian cancer test was investigated by scientists at the Georgia Institute of Technology. The test requires just one drop of blood serum, which they vaporized by hot helium plasma. Mass spectrometry was then used to measure the molecules, called metabolites, that are involved in metabolism. A technique then sorted the metabolites found in cancerous plasma from those found in healthy samples. The results were mapped to uncover the biological meaning of the metabolic changes.
The initial tests involved 94 women, and the investigators achieved 100 percent accuracy in identifying sera from women who had ovarian cancer from normal controls. No false positive or false negative results were reported.
John McDonald, professor of biology at Georgia Tech and chief research scientist at the Ovarian Cancer Institute in Atlanta noted that given the low prevalence of ovarian cancer, tests for the disease need to be extremely accurate. “We believe we may have developed such a test,” he said.
Currently, the researchers are conducting another set of tests and hope to include 500 patients. Because they do not have 500 women with the same type of ovarian cancer, they may look for other types of ovarian cancer as well. This new test may also be useful for other types of cancer, so the investigators will use the test to look for them too.
Doctors currently lack a highly accurate test for ovarian cancer. Scientists are hopeful the analysis of metabolites in blood serum will prove to be an accurate test for ovarian cancer and thus allow doctors to identify the disease early and save lives.
Georgia Institute of Technology
National Cancer Institute