A hope that Ovarian Cancer screening may save lives!
Each year, about 20,000 women in the United States get ovarian cancer.
Ovarian cancer accounts for approximately three percent of
cancers in women. Ovarian cancer ranks fifth in cancer deaths
among women, accounting for more deaths than any other cancer of the female
reproductive system.
A woman’s lifetime risk of developing invasive ovarian cancer is 1 in
75. A woman’s lifetime risk of dying from invasive ovarian cancer is 1 in
100.
Ovarian cancer rates are highest in women aged 55-64 years. The median age
at which women are diagnosed is 63, meaning that half of women are younger
than 63 when diagnosed with ovarian cancer and half are older.
Ovarian cancer has a poor prognosis, with just 40% of patients surviving 5
years.
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| image courtesy: seers data |
The American Cancer Society estimates for ovarian cancer in the United States
for 2015 are:
-
About 21,290 women will receive a new diagnosis
of ovarian cancer.
- About 14,180 women will die from ovarian cancer.
A paper published on-line in Lancet on December 17, 2015,
gives us the first evidence that screening can save lives from ovarian cancer
as a paradigm shift in our approach to the disease.
UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS) is a
Randomized
control trial which recruited more than
200,000
postmenopausal women aged
50–74
from June 2001 to October 2005
The women were assigned to one of the following three groups in the ratio of
1:1:2
- 50,624 underwent annual multimodality screening,
which consisted of a serum cancer antigen 125 (CA125) test interpreted
with the risk of ovarian cancer algorithm (ROCA) plus ultrasound;
- 50,623 underwent annual transvaginal ultrasound
screening alone;
- 101,299 underwent no screening.
The women in 13 centers in UK
followed for nearly 14 years with a median of 11.1 year.
Annual screening in the MMS
group used serum CA125 concentration testing, with the pattern over time
interpreted with use of the risk of ovarian cancer calculation ( ROCA), which identifies significant rises in CA125
concentration above baseline.
Next, ROCA
triaged women to normal (annual screening), intermediate (repeat CA125
concentration testing in 3 months), and elevated (repeat CA125 concentration
testing and
transvaginal USS as a
second-line test in 6 weeks) risk
Annual screening in the USS
group used transvaginal USS as the primary test, which was classified as normal
(annual screening), unsatisfactory (repeat in 3 months), or abnormal (scan with
a senior ultrasonographer within 6 weeks).
In both groups, women with
persistent abnormalities had clinical assessment and additional
investigations within the NHS
by a trial clinician.
The primary outcome was ovarian cancer death by Dec 31,
2014, secondary outcome was death due to ovarian and primary peritoneal cancer.
At a median follow-up of 11.1 years (interquartile range, 10.0 - 12.0),
ovarian cancer had been diagnosed in 1282 (0.6%) women — 338 (0.7%) in the
multimodality group, 314 (0.6%) in the ultrasound group, and 630 (0.6%) in the
no-screening group.
When the researchers analyzed the 14-year data, they found a reduction in
the rate of death from ovarian cancer of 15% (95% confidence interval [CI], –3
to 30;
P = .10) in the multimodality group and of 11% (95% CI, –7
to 27;
P = .21) in the ultrasound group.
The screening test involves a simple blood test, which can be done anywhere
and sent to a lab," he said. This could have an effect on the more than
100,000 deaths from ovarian cancer each year around the world.
Overall, there was an average reduction in mortality of 20% in favor of
multimodality screening. The reduction in mortality was 8% in the first 7 years
and 28% in the subsequent 7 years.
Cancer was detected at an early stage in more patients in the multimodality
group than in the no-screening group (39% vs 26%;
P < .0001).
Experts opinions on the trial
This is the first-ever evidence to suggest that screening for early
detection of ovarian cancer may save lives," said Ian Jacobs, MD,
president and vice-chancellor of the University of New South Wales in Sydney,
Australia , in a news bulletin.
"More follow-up is needed, but the results are encouraging and exciting
and open up the possibility that many lives could be saved," said Dr
Jacobs, who led the trial with Usha Menon, MD, from the Institute for Women's
Health, University College London, United Kingdom.
"Research now needs to accelerate to refine screening and confirm the
benefit, so that, in due course, widespread national screening programs can be
put in place," Dr Jacobs said.
"We have the first evidence that ovarian cancer screening can save
lives, but we need further follow-up to confirm the findings," added Dr
Menon.
"However, screening is not without harms, which include some women
undergoing surgery to find they only have benign ovarian lesions or normal
ovaries," she told
Medscape Medical News.
Experts agree that longer follow-up is needed to determine how effective
annual screening will turn out to be.
"Although still at an early stage, the initial results from the UKCTOCS
trial into screening for ovarian cancer are promising," Clare Mckenzie,
MD, consultant gynecological oncologist and vice president of the Royal College
of Obstetricians and Gynaecologists, said in a statement.
Gary S. Leiserowitz, MD, professor and chair of the
Department of Obstetrics and Gynecology, and chief of the division of
gynecologic oncology at the University of California Davis Health System in
Irvine commented that "Two other
studies — one from Japan and the Prostate, Lung, Colorectal and Ovarian (PLCO)
Cancer Screening Trial from the United States — were smaller, and neither
showed statistically significant benefits to large-scale ovarian cancer
screening. The UK
trial showed some evidence of early detection with both multimodality and
ultrasound, plus moderate reduction of mortality using post hoc
statistical analyses. The effects were greater with longer follow-up."
So far, results suggest that approximately 15 deaths could
be prevented with CA125 screening for every 10,000 women screened, Dr Mckenzie
noted. "However, for every woman with a positive screen who underwent
surgery and was found to have ovarian cancer, two did not," she added.
Karen H. Lu, MD, chair of gynecologic oncology and
reproductive medicine at the University of Texas M.D. Anderson Cancer Center in
Houston said
that “I believe that while the results from UKCTOCS are not practice-changing
right now, they have a very real potential of being practice-changing in the
near future."
Conclusion.
Key strengths of this trial
include scale, with more than 202000 participants, more than 670000 annual
screening episodes, and more than 2·19 million women-years of follow-up; the multicentre setting within the
UK NHS.
The main limitation of this
trial was failure to anticipate the late eff ct of screening in the statistical
design.
Implications of all the available
evidence --Our findings suggest that a multimodal approach to screening might
detect ovarian cancer sufficiently early to reduce mortality. To establish the
magnitude of this reduction in deaths, a longer duration of follow-up is
needed. Meanwhile, efforts to refine ovarian cancer screening strategies should
continue.
References:
http://www.thelancet.com/journals/lancet/article/PIIS0140-6736%2815%2901224-6/abstract
http://www.cdc.gov/cancer/ovarian/statistics/
http://www.ovariancancer.org/about/statistics/
http://www.cancer.org/cancer/ovariancancer/detailedguide/ovarian-cancer-key-statistics
http://www.medscape.com/viewarticle/856099#vp_1
