Back to basics: Pap tests, old and new
The incidence and prevalence of cervical cancer in Canada has declined dramatically
since the introductionof the Pap test for cervical cancer screening in the
1950s. Yet women continue to die from this preventable disease. This year,
approximately 1400 Canadian women will be diagnosed with cervical cancer and
420 are expected to die from it.
Although a few of these women probably had incorrect Pap test results, research
indicates that approximately 50% of these women never had a Pap test at all.
However, even in those cases where women are being screened, the Pap test has
limitations:
- It can give a false-negative result;
- Practitioners can take unsatisfactory samples; and
- Different cytologists can give different readings about the severity of
the condition revealed by the smears.
More recently, a liquid based cytology process has been developed which is
more reliable and eliminates some of the problems associated with traditional
Pap tests. Though it is costly to introduce, practitioners and cytologists
appear to prefer it to the Pap test. It is currently being introduced and tested
in several provinces in Canada, including Quebec and Newfoundland.
HPV tests offer more information
We know that specific strains of Human Papillomavirus (HPV) are definitively
linked with cervical cancer. Because the Pap test is not designed to assess
the presence of HPV infections, new tests have been developed to detect HPV.
Researchers now believe that most young people who engage in sexual activity
carry HPV viruses. In most cases, HPV leaves the body naturally. But some of
the strains linked with cervical cancer can persist, especially in women over
30 years of age. The good news is that there is now a HPV test that is available
to determine the presence of those strains linked with cervical cancer.
Proponents of the HPV test urge its use instead of the Pap test, or in conjunction
with the liquid based Pap test, as a triage tool for women over 30 to determine
which abnormal smears could possibly progress to severe abnormalities and/or
cancer.
Centres in the United States and the United Kingdom have been evaluating protocols
for the use of these two new technologies for a number of years. Here in Canada,
we are only beginning to incorporate liquid based technology and HPV testing
into provincial screening programs.
Screening to save lives
Women's voices absent
In November 2003, Health Canada and the Society of Obstetricians and Gynecologists
of Canada co-hosted a Pan Canadian Forum on Cervical Cancer Screening in Ottawa.
Professionals involved in cervical screening were invited to discuss emerging
issues and begin consensus-building about the launch of new tests in Canada.
The focus of the Pan-Canadian Forum was primarily on HPV testing. The sponsors
of this meeting included Health Canada and four pharmaceutical companies promoting
new technologies including the HPV test.
This new technology will have consequences on both the health and health care
of most women in Canada, yet women's voices were missing at the Forum and,
for the most part, are absent at the multiple levels of discussions and policy
formation about these forthcoming technologies and protocols.
Those in attendance at the Pan-Canadian Forum were almost exclusively professionals
working with screening programs. A few family physicians who had lobbied for
an invitation the week before the meeting were also present. A representative
from the Canadian Cancer Society was on the meeting's planning committee, but
did not attend the Forum.
The Canadian Women's Health Network (CWHN) was the only voluntary organization
present at the Forum. No other grassroots groups were represented. This was
very much in contrast to other national meetings on health issues such as HIV/AIDS
or breast cancer where significant numbers of voluntary, grassroots and women's
organizations are routinely included. As representatives for the CWHN, we were
disappointed by the exclusion of women from the Forum - to our knowledge, no "consumers" of
the HPV test were invited to share their perspectives at the meeting.
Not only were women's voices not present at the meeting, but important issues
related to the potential impact of these new tests on women's lives were not
in the forefront. While numerous participants raised these concern (often passionately),
most of the discussion at the meeting focused on the capabilities of the technology
and the implications for the health care system.
Inadequate public education
Among the protocols recommended in the report that emerged from the meeting were
new screening guidelines that include HPV testing. Other recommendations included
calls for public education on the links between HPV and cervical cancer. Yet
these educational proposals did not include any demands for the funding that
would be necessary to implement them.
We attended the workshop on education and were assured by members of various
provincial screening programs that good HPV education materials already existed
and could simply be collated and integrated within the pilot projects. We examined
the various materials proposed and found them to be utterly inadequate. They
do not include the perspectives or concerns of women as expressed by women
themselves. Nor do they provide sufficient information for women to make informed
decisions about HPV testing procedures.
Studies in the United
States and the United Kingdom demonstrate that general knowledge of HPV among
the general population of women is poor. Several American studies have found
that receiving a diagnosis of high-risk (for cervical cancer) HPV produced
emotional distress, sexual problems, concerns about transmission and negative
self-image. There is also evidence of resistance to disclosing HPV status
to sexual partners because of the embarrassment and fear of a partner leaving
the relationship.
A qualitative study in the UK found that while women welcome the introduction
of HPV testing, they were also concerned about the potential psychosocial
harm such a test might have on their relationships with partners (e.g., trust,
fidelity issues), family (e.g., discussions of safe sex behaviours) and community
(e.g., stigma, non-traditional beliefs and practices). Another recent study
showed that women do not understand the links between cervical cancer and
HPV. Therefore, women with mild or unclear Pap results who had an HPV test
became anxious and distressed.
We have seen almost nothing in the existing Canadian educational materials
that addresses these complex issues around HPV as a sexually transmitted infection
and a factor in cervical cancer. In the UK the introduction of HPV testing
included focus testing with women in order to craft the appropriate educational
materials that need to be provided before, during, and after the HPV test.
The head of the cytology programs in the UK was a speaker at the Pan Canadian
conference in November. He was the only featured speaker who actually raised
the importance of "beginning where women are." It is an important
message for health care professionals here in Canada.
A new opportunity
In 1989 the National Workshop on Screening for Cancer of the Cervix recommended
setting up organized cervical screening programs across Canada. While some
provinces, notably British Columbia, set up programs, no province or territory
has implemented all of the recommendations outlined in the report - most
notably, a recall system whereby women would receive regular notices to be
tested.
The failure of our health care system to reach women for testing, combined
with a lack of available information about the link between HPV and the risk
of cervical cancer, is a real danger to women's health. Communicating the preventable
nature of cervical cancer and reaching women who are not part of screening
programs are critical concerns requiring innovative community based solutions.
HPV testing could provide a new opportunity to holistically address cervical
cancer prevention in Canada, if both increased participation in cervical testing
and the introduction of HPV testing are linked. But recruiting women to undergo
Pap tests and the use of the new tests at a population level requires an improved
understanding of women's knowledge about and attitudes towards cervical cancer,
HPV and HPV testing.
The feasibility of successfully launching a "women-centred" approach
to HPV testing in Canada depends on the professional community's willingness
and ability to consult and work with women. While professionals advocating
for HPV testing in Canada may be motivated by the "best of reasons," their
actions need to be informed by women's own perspectives. Without this input
they risk perpetuating paternalistic and naïve approaches that are unlikely
to be well received by today's knowledgeable health care consumers. They will
neither decrease the numbers of women with cervical cancer, nor save women's
lives.
Robin Barnett is a community based consultant in women's
health; Jean Shoveller is Associate Professor at University
of British Columbia's Department of Health Care and Epidemiology.
Cervical
cancer vaccine
No such thing as a 'magic bullet'
Two pharmaceutical companies, GlaxoSmithKline (GSK) and Merck & Co. are racing
to become the first to sell a new cervical cancer vaccine. GSK is the world's
second-largest drug maker. Merck is half the size of GSK.
The two companies claim that their vaccines are 100% effective in protecting
women against two strains of HPV linked to more than 70% of all cases of cervical
cancer. GSK is filing for regulatory approval for the vaccine in Europe and
countries outside the US in 2006 -- two years ahead of schedule. This would
mean introduction in the US around 2008.
According to Dr. Diane Harper, a Dartmouth Medical School gynecologist, and
the author of a GSK-funded study, "There has been nothing else developed over
the last 20 years that will make such a huge impact on women's health." She
predicts that both Merck and GSK's treatments will prove at least 90% effective.
But in the rush to celebrate the potential of the vaccine are some important
issues being overlooked?
HPV may be the most common sexually transmitted disease worldwide, infecting
75% of sexually active women at some point in their lives, but for the majority
of women who contract HPV, the body's natural defenses are enough to beat the
virus.
In North America, the women who are most likely to die of cervical cancer
are poor and lack the resources needed for good health, such as food security
and adequate nutrition, access to health care, including regular Pap tests,
and, most likely, any new vaccine.
As well, an estimated 80% of deaths from cervical cancer occur in the developing
world, where Pap tests and cancer screening are rare and a woman's overall
health is more likely to be compromised because of poverty. Will the vaccine
be available to these women?
Perhaps the possibility of profit is pushing the vaccine's progress. According
to a British newspaper, a GlaxoSmithKline executive told investors that "the
marketing opportunity for the vaccine is absolutely huge." This is good news
for Merck as well, as they look for something to replace Vioxx, their best
selling drug withdrawn recently because of a link to heart attacks and stroke.
Our experience has taught us that it takes more than "better" drugs
or "improved" medical techniques or technologies to have a truly
positive impact on women's health. Until we see women's
knowledge and experience included in all phases of vaccine testing and eventual
use, (and not just as research subjects), we will continue to question its eventual
benefits.
Written by: Robin Barnett and Jean Shoveller
Posted: September 13, 2005
