Removing Benign Ovarian Cysts Does Not Affect Cancer Risk

From the WebMD Archives

March 23, 2000 (Lake Tahoe, Calif.) -- Removing noncancerous ovarian cysts does not seem to reduce a woman's risk of dying of ovarian cancer, according to a new study by researchers in London. The study, published in the March 25 issue of The Lancet, found that women who had these cysts removed were statistically no more or less likely to die of ovarian cancer than other types of malignancies, including breast, cervical, colorectal, or lung cancer.

The benign cysts were detected by ultrasonography -- the use of sound waves to create an image of an internal organ, in this case the ovaries. For women who are not at high risk of developing ovarian cancer, the study raises doubts about the benefit of detecting cysts that aren't causing symptoms. For women at high risk of this cancer, though, experts who spoke with WebMD advise having the test regularly. A woman's age and her family and reproductive history help determine her likelihood of developing this disease; women should ask their doctors if they're at risk.

"This research suggests that most benign cysts in middle-aged women would probably do no harm if they were left in place. But there is still a problem in trying to distinguish them from the malignant ones," lead researcher Timothy J. B. Crawford, MD, tells WebMD. "In the right hands, ultrasound is good at distinguishing benign from malignant cysts without need for an operation," he says. But in a small number of cases, he says, patients still need surgery in which the cyst is removed and examined under a microscope.

"I think the technology and the skill of the [doctors who perform] ultrasonography is evolving. We are better able to judge benign vs. malignant than we were years ago. However, it is still not a perfect tool," says Diane Bodurka-Bevers, MD, who reviewed the study for WebMD.

In the study, more than 5,000 women who had participated in an ultrasound screening trial for early ovarian cancer in the 1980s were followed for an average of 15 years by researchers at Guy's, King's and St. Thomas' School of Medicine in London.

In the earlier screening trial, the ultrasound had detected an ovarian abnormality that required surgical evaluation in 326 of the women. Nine of the 293 women who agreed to have surgery were diagnosed with ovarian cancer, and 112 had benign ovarian tumors. The others were found to have tumor-like conditions such as simple cysts. A total of 202 of the women had their ovaries and fallopian tubes removed.

"We believe that if the removal of benign (premalignant) cysts were to have an important effect on screening programmes, the subsequent incidence of ovarian cancer should have been reduced by at least 40%," write the authors.

However, the researchers found this did not occur. In the years that followed, 387 of the women who had taken part in the screening trial died. The cause of death in 221 of them was cancer; and 22 died of ovarian cancer -- slightly less than the number of deaths that would normally be expected from the malignancy, based on population and epidemiologic data.

"There have been other studies that looked at this, and no one was ever able to prove anything. But none of those studies had this number of patients. In the early '80s, when this work was done, Ca-125 [a tumor marker found in blood] didn't even exist, so ultrasound was the only thing we knew to use," Thomas Lallas, MD, tells WebMD. Lallas, a specialist in ovarian cancer at Lenox Hill Hospital in New York, was not involved in the study.

"We recommend that [women at high risk for ovarian cancer] see a gynecologic oncologist every six months to have a blood test for CA-125, a pelvic examination, and a transvaginal ultrasound. That's pretty much the state-of-the-art care," says Bodurka-Bevers, who is assistant professor of gynecologic oncology at the University of Texas M.D. Anderson Cancer Center in Houston.