While survival rates among patients with ovarian cancer have increased in recent years thanks to newer and more personalized treatment approaches – including the groundbreaking addition of PARP inhibitors – one major question still remains: How can the disease be detected in its earlier stages?
“This has been the ‘Holy Grail’ of ovarian cancer for as long as I’ve been alive,” Susan C. Modesitt, M.D., director of the Gynecologic Oncology Division and the High-Risk Breast/Ovarian Cancer Clinic at the University of Virginia, said during an Ask the Experts session at the OCRFA Ovarian Cancer National Conference.
“If we found everyone in stage 1, then we would have a 90 to 95 percent cure rate,” she added.
But that is not always easy, especially since ovarian cancer often presents itself with symptoms mimicking a variety of other things, from gastrointestinal issues to pregnancy. Also, Modesitt mentioned that not all ovarian cancers start off in the ovaries. For example, abnormal pre-cancerous cells can start off in the fallopian tubes and then eventually move to or near the ovarian cancer. Even then, the cells are so tiny that they cannot be picked up by ultrasound or a cancer antigen 125 (CA-125) test.
CA-125 is currently the closest biomarker that physicians have to detect ovarian cancer, and the test measures the amount of the CA-125 protein a woman has in her blood.
However, it is a far from perfect way to test for ovarian cancer. In fact, earlier this year, the United States Preventative Services Task Force (USPSTF) determined that screening women with no known risk for ovarian cancer could end up doing more harm than good
and lead to unnecessary medical procedures and surgeries. They found that screening via transvaginal ultrasound or CA-125 testing in this population did not reduce mortality.
Amanda Nickles Fader, M.D., associate professor and director of the Kelly Gynecologic Oncology Service in the Johns Hopkins Department of Gynecology and Obstetrics, another panel member at the presentation, echoed Modesitt’s concerns.
“Because these tumors are so difficult to pick up at an early stage with the existing commercial tests like ultrasounds and CA-125, we’re looking at other things on that molecular or genetic level,” she said.
And so, the hunt is on for a better biomarker.
“If you name a tumor marker or any protein, we’ve looked at it for ovarian cancer,” Modesitt said. “And nothing yet has out-performed CA-125 as a single entity.”
Researchers at the Dana-Farber Cancer Institute and the Brigham and Women’s Hospital recently developed a blood test that could identify a network of microRNAs associated with ovarian cancer. According to their study, which included more than 450 patients, this test outperformed CA-125
and produced fewer false positives, too.
However, this test is still in its early stages and years away from potentially hitting the market.
In the meantime, Modesitt said that her team is working on a variety of different studies with the same hope of catching ovarian cancer in its earliest stages. This includes collecting cervix and fallopian tube cells. She is even working on one study that collects tampons from women in search for an indicator that they may one day develop the disease.
“We call it the tampon study. It’s a crowd pleaser,” she joked. “We get creative in medicine.”
Moedsitt’s team is not the only group attempting to find better detection for ovarian cancer. In fact, she mentioned that institutions across the globe are all working hard with that same goal in mind.
“There’s a lot of work being done on this, so I hope that we’re going to start really having a better way to identify these pre-cancerous changes before all of these events transpire,” Modesitt said. “So, there’s a lot of exciting stuff going on, and I’m hopeful that we’re going to do something good with this in the next five to 10 years.”