Exploring the impact of screening
December 21, 2015
Results of UK research trial
One of the world’s largest ever research trials recently posted findings that were 14 years in the making. The UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS) estimates that a new approach could reduce the number of lives lost to ovarian cancer by one-fifth (20 per cent).
Earlier results from this same study showed that a calculation called the Risk of Ovarian Cancer Algorithm (ROCA) could help detect twice as many ovarian cancers when compared to current methods. To assess a woman’s risk of ovarian cancer, ROCA looks at changes in her CA125 (a protein that can indicate the presence of a variety of different tumours) over time.
Despite the positive interim result, the question remained: could screening for ovarian cancer save lives?
In the recent announcement, evidence was inconclusive. But while screening for ovarian cancer could not be recommended, scientists seemed encouraged.
Results show that reductions in mortality occurred in the latter half of the trial. Accordingly, researchers are continuing to track participants for an additional three years to gather more information in hopes of confirming the benefit of screening.
Meanwhile, concerns surrounding the cost effectiveness of screening and the risk of harm tied to unnecessary surgeries have yet to be addressed.
Details of the trial
Started in 2001, UKCTOCS enlisted support from 202,638 post-menopausal women. Each participant was randomly assigned to one of the following groups:
1. The screening group in which women were tested annually
a. Some had an annual CA125 blood test
b. Others had a transvaginal ultrasound once a year
2. The control group, which had had no tests at all
The Risk of Ovarian Cancer Algorithm was used to interpret results of women who received CA125 testing. Based on a participant’s age, her original CA125 level, and changes to that level over time; the calculation gauged risk for developing ovarian cancer. If the participant’s risk was seen as intermediate or elevated, she was sent for further tests.
The women who went for annual transvaginal ultrasounds were also sent for additional tests when abnormalities were detected.
In both these screening groups, women had more extensive testing with referral for surgery if there was a persistent abnormality.
Over the course of 14 years, all participants in the trial were asked to complete follow-up questionnaires regarding their health outcomes and were further tracked though Health and Social Care Information Centres.
In conclusion
Though it will take another three years for more definitive evidence, results from UKCTOCS represent a milestone in ovarian cancer research. In preparation for the future announcement, the UK National Health Service is taking steps to determine requirements for pilot projects.
“We congratulate our colleagues in the UK and are cautiously optimistic about their research findings to date,” says Elisabeth Baugh, CEO of Ovarian Cancer Canada. “Though further confirmation is needed, results seem to suggest that it may be possible for screening to save lives in the future. We look forward to hearing more.”
Ovarian Cancer Canada is launching a government relations effort aimed at increasing research to address gaps in diagnosis and treatment of this disease. Stay tuned for more information.
A video recording the UKCTOCS announcement is now available: https://youtu.be/N8H6oN21rrw
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