The issue of screening for ovarian cancer is close to my heart as I care for several patients with widely spread ovarian cancer and wonder: could we have done this better and discovered this sooner?
Sadly, it looks like ovarian cancer may be similar to lung cancer because no screening test has been identified that will lower death rates from that cancer. A new study has shown that screening for ovarian cancer doesn’t prevent death from ovarian cancer.
Even with CA-125 blood tests and transvaginal ultrasound once a year, mortality rates from ovarian cancer didn’t change, and there were many unnecessary procedures for benign findings. That is worrisome.
To determine the effect of ovarian cancer screening on death from ovarian cancer, researchers from the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening trial assigned women to an intervention group (screening with CA-125 and transvaginal ultrasound at baseline, and once a year for three to five years) to a usual care group with no annual screening.
There was no difference in mortality from ovarian cancer in the two groups. Even more distressing was that in the group receiving ultrasounds yearly false-positive results resulted in many surgical procedures with serious complications. In other words many benign ovarian masses/cysts were removed at a medical cost to the patient (infection, cardiac and pulmonary complications, etc.).
I can guess at the reasons once a year screening may not prevent death from ovarian cancer: ovarian cancer is fast growing and aggressive and pops up in between screening tests, and the screening tests aren’t perfect and may miss early stage ovarian cancer.
What we do know from this large study is that the screening strategy of once a year CA 125 blood test and transvaginal ultrasound does not reduce mortality in women at average risk for ovarian cancer, and does increase invasive medical procedures and associated harms.