Ovarian Cancer News

By David Liu,PHD

Tursday July 26, 2012 (foodconsumer.org) -- Ovarian cancer is not as common as breast cancer. But this disease is deadlier than breast cancer.   The disease is expected to be diagnosed in 22,280 women in 2012 and it will kill 15,500 women in just a year. Diagnosis of the disease is often late and the five-year survival is only 20 to 30%.

Because of the high risk, women are often urged by their physicians to receive an annual screening.  But research suggests that no screenings thus far used are safe and effective and they actually do more harm than good.

The US Preventive Services Task Force (USPSTF) updated its ovarian cancer screening recommendation in April in 2012 saying that ovarian cancer screening had little effect on reducing mortality rates while it increased the risk of harms, according to Anita Slomski.

Anita Slomski reported in JAMA on June 20, 2012 that two methods transvaginal ultrasonography (TVU) and serum tumor marker cancer antigen CA-125 are just not good enough to be used as screening tools for ovarian cancer in asymptomatic women.

The task force, according to the author, reviewed 3 more recent randomized controlled trials in addition to an early review leading to a grade D recommendation in 1996.  The new review convinced the task force to upheld its early position that no evidence suggests that routinely screening asymptomatic women at average risk for ovarian cancer.

Gynecologic oncologists welcome the recommendation.  The author cited Ronald Alvarez, MD, professor of the University of Alabama at Birmingham as saying "Practitioners need the authority of the USPSTF to make the argument to patients who don't fall into a high-risk group that these tests may do more harm than good."  Alvarez said "Physicians use these tests more often than they should.”

One clinical trial reviewed by the task force is the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trials, which was published by S.S. Buys and colleagues in JAMA in  2011. 

In the trial, 78,216 women aged 55 to 74 were given usual care or annual screening for six years with CA-125 and for four years with YVU.   Screening as readers can image identified more ovarian cancers that the usual care, that is, 212 cases were found  in the screened group, compared to 176 cases in the control group. The majority of ovarian cancer in both groups were stage III or IV tumors.   In the screened group, 118 ovarian cancer deaths were recorded, compared to 100 in the group receiving usual care.  (The numbers suggest that screening even slightly increased the death risk.

David Grossman, MD,  MPH, task force member and senior investigator at the Group Health Research Institute in Seattle was cited as saying "There were also significant harms when you considered the number of women who had false-positive results and had surgery even though they didn't have cancer."

What kind of harm could the screening cause?  Anita Slomski wrote in her report that "Of the 10% of women in the PLCO trial's intervention group who had a false-positive result, one-third had an oophorectomy—33% more oophorectomies than in the control group—and 15% had a serious complication, such as infection, surgical complication, or a cardiovascular or pulmonary event."

Considerable harms associated with ovarian screening were also observed in The Shizuoka Cohort Study of Ovarian Cancer Screening in Japan, which was published by H. Kobayashi and colleagues in 2008 in International Journal of Gynecological Cancer.  

The trial found in order to detect one case of ovarian cancer in the screened group, an estimated 33 surgeries were needed.

In the ongoing UK Collaborative Trial of Ovarian Cancer Screening, less than 1% of the subjects had surgery as a result of an abnormal screening results.   But 69% of the 1% of women ended up being found to have no cancer.  The study was led by U. Menon and colleagues and published in Lancet Oncology in 2009.

Even worse, Anita Slomski cited Alvarez as saying "we have no evidence that these tests (TVU and CA-125) reduce mortality in high-risk patients either."   For high risk women, according to Alvarez, there are more effective ways of reducing ovarian cancer risk including using birth control pills, and prophylactic salpingectomy and oophorectomy.

Women who are at high risk of developing ovarian cancer are those who have BRCA genetic mutations, Lynch syndrome, personal history of premenopausal breast cancer, or strong family history of breast and ovarian cancer.