Ovarian Cancer Screenings Don't Save Lives
Ovarian cancer screenings have no effect on saving lives, says new study.
According to researchers, women undergoing dual screenings for ovarian cancer have no decreased risk of mortality from this deadly disease. The study was conducted to see if comprehensive screening to detect the cancer at earlier and more curable stages would help reduce one's risk of dying.
Ovarian cancer is the 5th leading cause of cancer death in women in the United States. The symptoms of this deadly disease are often vary vague and therefore most women are unaware of the cancer before it reaches advanced stages. The 5-year survival rate for ovarian cancer if it is not caught early is a mere 30 percent.
The findings of this study are from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO) sponsored by the National Cancer Institute. Researchers randomized over 78,216 women across the U.S. ranging in ages 55 to 74 to either an ovarian cancer screening group or a control group. For six years the screening group received CA-125 testing (blood test that detects ovarian cancer) along with transvaginal ultrasounds. The control group did not receive either screen.
After a 12 year follow up the researchers found that, although 20% more cancers were detected in the screening group, there was no decrease in risk from dying as a result of the disease. In fact, the screening group actually had an increased risk of death compared to those who received no screening at all.
"It is possible that even an optimized program of annual screening may be insufficient to detect cancers early enough to reduce mortality," says authors of the study published online in The Journal of the American Medical Association (JAMA).
The authors suggested in their conclusion that perhaps aggressive cancers progress too quickly through the early stages of the disease, making yearly screenings limited in their ability to detect them while they are still in those stages. Furthermore, they also comment that increased screenings could lead to harmful over-diagnosis. “More ovarian cancers were diagnosed in the screened group than in the usual care group (212 vs 176), suggesting that some of the additional cancers detected by screenings were not clinically important and, if left undetected, may never have caused any symptoms or affected the women during their lifetimes.”
Additionally, the screening group had a 5% false-positive rate, leading to an increased amount of unnecessary invasive procedures - which was concerning for the researchers.
To date there has been no ovarian cancer screening that has proved to be useful in reducing death from this disease. However, in addition to the PLCO study there are two other studies, one in Japan and one in the UK, that are currently evaluating the use of the CA-125 and transvaginal ultrasounds. Final results from these studies have not yet been published.
Resource: Buys SS et al. "Effect of screening on ovarian cancer mortality. The Prostate, Lung, Colorectal, and Ovarian (PLCO) cancer screening randomized trial" JAMA 2011; DOI: 10.1001/jama.2011.766.