Betsy Neisner sent me some links to interesting articles from a continuing education webpage.
Here's one of the articles I read and I thought I'd share with you.
There are several more I will be posting.
If you are interested the website is called "MyCME". Just google it!
Ovarian Cancer Screening Study Falls Short
Significant mortality benefit only in
subgroup analysis
Staff Writer, MedPage
Today
December 17, 2015
The largest-ever
screening study for ovarian cancer showed a modest reduction in the risk of
dying of the cancer after more than a decade of follow-up, but failed to
demonstrate a significant difference from no screening.
The primary analysis
showed annual risk reductions of 15% and 11% with the two different methods of
screening evaluated in the trial. Neither difference achieved statistical
significance versus no screening. A prespecified analysis limited to patients
screened with both a blood test and ultrasound (using different statistical
methods) did yield a significant 20% annual reduction in ovarian cancer
mortality risk.
Follow-up will
continue in the trial to determine more precisely the magnitude of mortality
reduction -- which could increase or decrease at this point -- and whether
routine screening in the general population is cost effective, Ian Jacobs, MD,
of University College London, and co-authors reported in The Lancet.
The preliminary
results showed that 641 women would have to be screened with an assay for the
cancer-related protein CA-125 plus transvaginal ultrasound to prevent one
ovarian cancer death. 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. Complications occurred in 3.1% of
the patients who underwent surgery.
The results will do
little to inform the debate on screening average-risk women, said Don Dizon, MD,
of Massachusetts General Hospital Cancer Center and a clinical expert for the
American Society of Clinical Oncology.
"I'm underwhelmed
by the results," Dizon told MedPage Today. "I think the summary of
the study that was distributed in advance was a bit misleading. It's a hopeful
study, regarding the benefits of screening, but the picture is still
incomplete. If anything, it should spur on research, but it is by no means a
green light to start screening the general population."
The U.S. Preventive
Services Task Force has recommend against routine screening of women who have
an average risk of ovarian cancer. The Centers for Disease Control and
Prevention also does not support ovarian cancer screening and declined to
comment on the British study.
The authors of a
commentary that accompanied the article by Jacobs, et al, said the focus should
be on determining how to maximize the benefits of available screening tools.
"If only 59% of
ovarian cancer cases are detected by screening plus ultrasound, we will need to
focus on why and how screening ... still has a significant, but delayed
survival effect," said Rene Verheijen, MD, and Ronald Zweemer,
MD, of the Utrecht Medical Center in The Netherlands. "Trying
to unravel the mechanism behind this effect so that it can be improved should
have high priority."
A majority of women
with ovarian cancer have advanced disease at diagnosis, and 5-year survival for
advanced disease is 40% or less. Most women have no symptoms preceding
diagnosis of ovarian cancer, fueling interest in methods of early diagnosis.
Jacobs and co-authors
reported initial findings from the U.K. Collaborative Trial of Ovarian Cancer
Screening involving more than 200,000 women ages 50 to 74. Investigators at 13
centers randomized 50,640 to annual multimodality screening, 50,639 to annual
screening by ultrasound only, and 101,359 to no screening. The primary endpoint
was ovarian cancer mortality.
Screening ended Dec.
31, 2011, and the trial had a median follow-up of 11.1 years (maximum of 14
years). Patients in the multimodality screening group underwent a cumulative
total of 345,570 screens, and the ultrasound group accumulated 327,775 screens.
By individual
screening methods, the analysis showed a 15% (95% CI -3% to +30%, P=0.10)
reduction in the risk of ovarian cancer death in the multimodality arm versus
no screening and 11% (95% CI -7% to +27%, P=0.21) in the ultrasound group. A
prespecified alternative method of statistical analysis (Royston-Parmar
flexible parametric model), limited to the multimodality group, did show a
statistically significant 20% reduction in the risk of ovarian cancer death
after excluded women who had ovarian cancer at enrollment(95% CI -2% to +40%, P=0.021).
Most of the mortality
benefit occurred during the later years of follow-up: 8% during years 0 to 7
versus 23% during years 7 to 14 in the multimodality group and 2% versus 21% in
the ultrasound group.
"In retrospect,
it would have been preferable to specify a primary analysis that was weighted
to reflect the predictable delay in mortality reduction in a screening trial of
this type," the authors said in their discussion.
"The main
limitation of this trial was our failure to anticipate the late effect of
screening in our statistical design," they added.
The late benefit
perplexed Dizon.
"When you think
about the benefit of screening, my understanding is that it should be realized
earlier, rather than later,” he said. "When you stop screening [in a randomized
trial], you're going to get cancers in both arms, and it may mask a survival
advantage of screening, unless it's life long."
The basis for thinking
the benefit might increase with longer follow-up is equally unclear,
particularly if women decide to stop being screened, Dizon added.
