Jan. 9, 2013 -- A new test for ovarian and endometrial cancers looks at cervical fluid obtained during a routine Pap test to detect genetic mutations linked with the cancers.
Although the research is in early stages, the test did well in detecting these cancers, says researcher Yuxuan Wang, a graduate student at the Ludwig Center for Cancer Genetics and Therapeutics at the Johns Hopkins University's Kimmel Cancer Center in Baltimore.
If ongoing research bears out, the new test could someday become a routine screening test, much like the Pap test is for cervical cancer, she says.
"This would not add anything to the current [Pap] procedure," Wang says. "All we do is take part of the sample for DNA testing.''
The cervical fluid collected during a Pap smear contains normal DNA and, if a person has cancer, DNA from those cancer cells.
The researchers used genomic sequencing to pick out the cancerous DNA from the normal DNA.
The study is published in Science Translational Medicine.
Problems in Detecting Ovarian, Endometrial Cancers
Widespread use of the Pap test has reduced deaths from cervical cancer and increased early detection. But finding reliable screening tests for ovarian and endometrial cancers has been elusive.
More than 69,000 U.S. women were expected to get a diagnosis of either ovarian or endometrial cancer in 2012.
If endometrial cancer is suspected, a doctor may order a transvaginal ultrasound. If ovarian cancer is suspected, a doctor may order a blood test that looks for CA-125, a protein found at high levels in some ovarian cancer patients.
Neither test is as reliable as a screening test, the researchers say. The U.S. Preventive Services Task Force and the American Cancer Society do not recommend general routine screening for endometrial or ovarian cancer.
Examining Pap Test Fluid
During a Pap test, cells collected from the cervix are examined for signs of cancer. The DNA in the Pap sample may also be examined for human papillomavirus (HPV), which causes cervical cancer.
The cervical fluid collected during the Pap test can also contain cells shed from the ovaries or the uterine lining (the endometrium).
Cancer cells from either the ovaries or endometrium could also be present in the fluid, the researchers say.
In the new study, the researchers determined the most common genetic mutations found in ovarian and endometrial cancers.
"We ended up with 12 genes," Wang says. The test they developed, called the PapGene test, looks for mutations on those 12 genes.
They searched for the mutations in 24 endometrial cancer tissue samples and 22 ovarian cancer tissue samples.
Mutations were found in all 46 samples.
They looked at the Pap test to see if the same mutations were found as they found in the tissue samples.