Annual Ultrasound Screening for Ovarian Cancer Fails to Reduce Deaths

Screening women annually with ultrasound or with an ultrasound-blood test combination does not reduce the number of deaths from ovarian cancer – results that fall short of investigator hopes.

In a large-scale randomized trial published May 12 in The Lancet, researchers from University College London (UCL) revealed the disappointing findings from the UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS) that showed, while screening can detect cancers earlier, it doesn’t save lives.

“UKCTOCS is the first trial to show that screening can definitely detect ovarian cancer earlier,” said lead investigator Usha Menon, UCL gynecological oncology professor. “However, this very large, rigorous trial shows clearly that screening using either of the approaches we tested did not save lives. We, therefore, cannot recommend ovarian cancer screening for the general population using these methods.”

Treating ovarian cancer is particularly difficult because it is typically diagnosed at a later stage. Roughly 14,000 women in the United States and 4,000 women in the United Kingdom die from the disease yearly. The team had hypothesized that an effective screening method for earlier detection would translate to more avoided deaths.

To test their theory, they examined data from 202,562 women between the ages of 50 and 74 who were enrolled in UKCTOCS between 2001 and 2005. Screenings lasted until 2011, and they followed the women until June 30, 2020. They randomly divided the women into three study arms: 50,625 women (25 percent) received annual multimodal screening (MMS) with an ultrasound and blood test, 50,623 (25 percent) received transvaginal ultrasound screening (USS), and 101,314 (50 percent) did not undergo screening.

Based on their analysis, the blood test included in MMS screening detected 39.2 percent of earlier stage cancers (Stage 1 or 2), as well as 10.2 percent of late-stage disease (Stage 3 or 4). The data revealed there was no difference in the stage of cancer detected by the ultrasound group when compared to the no screening group.

Overall, during the study, 2,055 women – roughly 1 percent of women in every study group – received an ovarian cancer diagnosis. A total of 1,206 women died – again, the same percentage of women (0.6 percent) from each cohort were impacted.

Given the amount of data collected during the trial, the team felt confident enough to conclude that ovarian cancer screening does not save lives. This means the road to population screening will be longer than desired.

“Population screening for ovarian cancer can only be supported if a test is shown to reduce deaths in a future randomized controlled trial” said co-investigator Ian Jacobs, a gynecological oncologist with the University of New South Wales who led the ovarian cancer screening research program since 1985. “I remain hopeful that a new effective screening test will be found eventually, but it will take many years to conduct a large trial of the test. Realistically, this means we have to reluctantly accept that population screening for ovarian cancer is more than a decade away.”

Although they did not receive the results they wanted, the team did say their study provided insights that can contribute to advances in risk assessment, prevention, and ovarian cancer diagnosis.

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