Pap test could improve ovarian cancer detection
LEWISTOWN – A recent study performed by scientists at Johns Hopkins University revealed the potential to screen for ovarian and endometrial cancer by using a regular Pap smear test. The study focused on DNA testing, which makes tumor markers visible and early detection possible.
This is the first real breakthrough in gynecologic cancer screening since the Pap smear test was discovered, said Dr. William Crowder, OB/GYN physician at Geisinger-Lewistown. Until now there has been no successful test for ovarian or endometrial cancer, he added.
“We have been looking for a way to screen for ovarian cancer for the past 25 years,” Crowder said. “The work being done at Johns Hopkins is very exciting and certainly a move forward.”
In the pilot study, Dr. Luis Diaz, an oncologist at Hopkins, and his team analyzed Pap smears from 46 women already diagnosed with ovarian or endometrial cancer. The team then performed DNA testing on cells that had separated from the ovaries or the uterus lining and landed in the cervix, where Pap tests are regularly performed.
If cancer is present in the test cells, there will be a gene mutation, or marker, that indicates a cancerous cell rather than a regular cell, Crowder said. Such mutations are not visible under a microscope and would remain undetected during regular Pap smear analysis, he added.
This new technique, refereed to as PapGene, was able to detect all endometrial cancers and 41 percent of the ovarian tumors, reported the Johns Hopkins team in the Science Translational Medicine journal.
The team is now collecting a much larger sample of Pap tests for further research. The next step, Crowder said, is to create a higher level of sensitivity in the test by finding more DNA markers that indicate the presence of cancer.
According to the National Cancer Institute, of the 22,280 women diagnosed with ovarian cancer in 2012, 15,500 did not survive. And of the 47,130 women diagnosed with endometrial cancer in 2012, 8,010 did not survive.
“This study has the potential to dramatically increase the cure rate through early detection,” Crowder said. “The mortality rates are so high because there is no specific symptoms or early detection methods for these cancers.”
If the study is ultimately successful, doctors will continue using the Pap smear test regularly at annual exams, Crowder said. Nothing will change for the patient because the extra work is performed in the lab, he added.
“While the initial results are important, the study involved a very small sample,” Crowder said. “It will probably take two more years of clinical testing to really learn what the new technique is capable of.”
The Pap test is currently used to screen for cervical cancer and HPV during regular annual exams, Crowder said. If PapGene is eventually used in doctors’ offices, the frequency of the Pap test might increase for certain age groups, he added.
“A woman should get her first Pap test within three years of initial sexual activity and on a yearly basis after that,” Crowder said. “If the Hopkins study pans out, Pap tests will most likely increase for older women since ovarian cancer is more prevalent in the older age groups.”
For more information on ovarian and endometrial cancer, visit www.cancer.gov.