Friday, January 22, 2016
Signs of ovarian cancer at an early stage in women with no risk factors for it are usually vague and can be easy to miss. Because the disease is often aggressive and deadly once it takes hold, researchers around the world are looking for practical ways to screen the general population. Memorial Sloan Kettering gynecologic oncologist Douglas Levine discusses the slow but steady advances being made in understanding how we can screen for and prevent deaths from this cancer.
- Researchers at MSK and elsewhere are making headway in developing strategies for screening women at average risk for ovarian cancer.
- Ovarian cancer is rare but often fatal, in part because symptoms are vague and it’s challenging to find early, when it’s easier to cure.
- Results of a major British study in December signaled potential for a multipronged screening approach that tracks CA-125 protein changes in the blood over time.
- The study confirmed that ultrasound imaging of the ovaries isn’t effective in screening women at average risk.
A worldwide effort is under way to find new methods to screen women with no known risk factors for ovarian cancer.
The disease is often aggressive and progresses quickly; only 40 percent of women who have it survive more than five years. Yet the diagnosis often takes women by surprise, as the cancer causes few if any symptoms when first developing. (Though screening guidelines already exist for women at increased risk for the disease due to a family history of the illness.)
Early diagnosis is essential, as surgery and other currently available treatments are more effective when ovarian cancer is identified at an early stage, before it has spread beyond the pelvis. When the disease is caught early, Memorial Sloan Kettering’s specialized ovarian cancer surgery team can remove all cancerous tissue relatively easily, often saving a woman’s life and, in some cases, eliminating the need for chemotherapy or other treatments.
Through Research, Hope for Effective Screening Options
Biomarkers: Proteins or other elements in the body that can be measured as an indication of disease.
With the discovery several years ago that most cases of ovarian cancer originate at the end of the fallopian tubes, investigators are zeroing in on new biomarkers — indicators that disease is present — and also learning more about known biomarkers secreted in high concentrations near this part of the body. Other studies are determining if biomarkers can be found in the bloodstream.
At MSK, researchers are exploring the value of “washing” the uterus with fluid and analyzing the fluid for biomarkers. This test is currently in a technology development phase (not in clinical trials), as researchers collect more samples from patients. Dr. Levine foresees its use one day in an office setting.
Nanotechnology: Science conducted on an atomic or molecular scale.
Another promising avenue of investigation utilizes nanotechnology to detect tiny bits of tumor proteins that may indicate ovarian cancer. Researchers are developing approaches to make this tactic reliably sensitive enough to spot ominous changes in both the bloodstream and fluid from uterine washings.
“Surgery to remove the ovaries and fallopian tubes has proven to be a lifesaver for women at high risk,” Dr. Levine adds. Researchers at MSK and elsewhere are planning studies to explore the removal of the fallopian tubes in average-risk women who’ve completed childbearing and are having pelvic surgery for unrelated reasons to see if there’s a protective effect.Back to top
Major British Study Also Advances Possible Solution
Late last year, findings from a major 14-year study in the United Kingdom — the largest randomized screening trial ever done for ovarian cancer — indicated potential for a multipronged screening approach in women past menopause.
The eagerly awaited United Kingdom Collaborative Trial of Ovarian Cancer Screening study, published in The Lancet, shows that measuring changes in the levels of CA-125 protein in women’s blood over the course of time, then using ultrasound screening for follow-up if problems are spotted, may one day lead to an approach that can save women’s lives.
Researchers followed the course of 202,638 women age 50 to 74 assigned to either this multimodal approach, no screening test at all, or an annual ultrasound scan of the ovaries.
“The study was promising in showing that if you do screening in the general population over a long enough period of time, you can detect ovarian cancer at an early stage. But they had to screen more than 600 women for 14 years to find one case of ovarian cancer,” Dr. Levine explains, noting the substantial cost and effort required to catch just a handful of occurrences for a relatively rare disease. “With the screening methods available today, we’d miss almost half of all cases.”
Three more years of the study remain; time will tell whether this multipronged approach makes sense. Given that the approach used in the study is proprietary and not yet available in the US, Dr. Levine notes “it’s yet to be seen how the test would be practical to use here.”Back to top
Ineffective: Screening Average-Risk Women with Ultrasound
The British study also confirms that transvaginal ultrasound technology isn’t effective for screening women at average risk for the disease, Dr. Levine notes — an insight MSK and other institutions have held for years already.
“As the first step in screening, it’s not the way to go, though we still do see average-risk women who’ve had screening ultrasounds performed elsewhere,” he says.
Meanwhile, the findings don’t in any way change MSK screening guidelines that women at average risk receive an annual gynecologic examination (with a pelvic examination) as part of a preventive healthcare plan.
“There’s still no definitive way to screen women at average risk,” says Dr. Levine, “but progress is being made at MSK and other institutions.”Back to top