Ovarian cancer was diagnosed in 1,282 women during the 14-year study of more than 200,000 post-menopausal women aged 50 to 74, of whom 649 had died of the disease by the trial end in December 2014. Women with ovarian cancer often have no symptoms or just mild symptoms until the disease reaches an advanced stage.
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It causes such vague symptoms until it’s progressed that few women know in time. “While this is an important step in ovarian cancer research we would not recommend a national screening programme at this point”. We must be realistic though, as this could take years to become a reality.
After the conclusion of the study, the researchers found out that on an average there was a 20% reduction in mortality overall due to the cancer screenings and a 28% reduction during 7-14 years after the diagnosis of ovarian cancer in the study participants.
The screening is based on an annual blood test called ROCA (Risk of Ovarian Cancer Algorithm), which uses a statistical calculation to interpret changing levels over time of a blood protein, CA125, which is linked to ovarian cancer. If levels of CA125 increased, women were sent for further tests. “The incidence is not high, but it has a high mortality rate and we’ve not been able to offer women much with respect to early detection”. The results also showed a small but clinically significant risk of harm, as 14 women with false-positive screening results had surgery that revealed no evidence of cancer.
More than 7,000 women are diagnosed with ovarian cancer each year and more than 4,000 will die from the disease, most because it was picked up too late for treatments to be effective. “It is possible that the mortality reduction after follow-up for an additional 2-3 years will be greater or less than these initial estimates”.
Kevin McConway, a professor of applied statistics at the Open University, said: “Doing these extra analyses can be seen as an appropriate response to how the data turned out to look, which in some respects weren’t as they originally expected. Meanwhile efforts can be made to refine ovarian cancer screening, develop tests with greater sensitivity and more lead time and improve ways to risk stratify the population”.
Ovarian cancer mainly hits older women after menopause, with an added risk from an inherited faulty gene.
‘Although this may be acceptable in terms of mortality benefit and comparison with other cancer screening programmes, there are significant clinical and resource implications of this screening method.
“While we’re not there yet, and will need to wait for further study and definitive results, UKCTOCS shows that research in the field is gaining pace”.
Derek Cruickshank, a consultant in gynaecological oncology, said: “It’s great that the trust has been involved in this important study”.
“However, longer follow up is needed to determine how effective the test is”.
The study found that around 15 deaths could be prevented by the blood test for every 10,000 women screened.
NCCP interim director Jerome Coffey said the conclusions of the study were interesting, but the findings were not clear or strong enough to justify a move to population screening at this stage.
Professor Nazar Amso, from Cardiff University’s School of Medicine and who led the Cardiff arm of the trial, said: “It’s been a privilege for Cardiff to be part of the largest ovarian cancer trial ever”.
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At a median follow-up of 11 years with the participants, 338 in the MMS group were diagnosed with ovarian cancer, 314 were diagnosed in the USS group, and 630 in the no screening group.
