Michael Douglas recently raised our awareness about the risk of Human
Papillomavirus (HPV) infection leading to oropharyngeal cancer.
HPV is a common Sexually Transmitted Disease (STD)
– here is a link to some information about HPV:
http://www.cdc.gov/hpv/whatishpv.html.
HPV can lead to both minor and major
health problems, including warts on the hands or feet, genital warts, and
cancers.
There are more than 160 types of HPV –
over 40 of which are transferred by mucosal or genital transmission, of these
40, two are responsible for most of the cancer risk, HPV 16 and HPV 18,
including cervical, anogenital and oropharyngeal cancers (Saraiya,2013).
Information on HPV-associated cancers can be
found here:
http://www.cancer.org/ and on
oropharyngeal cancer here:
http://wwwnc.cdc.gov/eid/article/16/11/10-0452_article.htm.
It is laudable that Douglas would disclose this,
particularly given the stigma related to STD’s.
He raises awareness of the risk of this STD to individuals (like middle
aged and older adults) who may not consider themselves at risk from exposure to
HPV decades earlier.
Unfortunately
little can be done to detect this form of cancer early.
Here is a useful guide from the American
Cancer Society related to oropharyngeal cancer:
http://www.cancer.org/cancer/oralcavityandoropharyngealcancer/detailedguide/index
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Douglas’ acknowledgement of the possibility of his cancer
being linked to sexual activity and HPV transmission has naturally raised the
question of what should be done about this risk? Men are at much higher risk of
developing oropharyngeal cancer from HPV than women.
Should we screen all men for HPV like women
are screened with pap smears to reduce cervical cancer risk?
Unfortunately there are difficulties to
screening for this type of cancer.
Here
is a video by the New York Times discussing some of these concerns:
http://www.nytimes.com/video/2013/06/10/health/100000002273386/a-collective-gulp.html?smid=pl-share
While screening programs are common and they are usually
viewed as only good – there are actually down-sides to screening – for example
what happens when it is very difficult to detect the presence of the HPV virus
(HPV-16 or HPV-18) that leads to throat cancer?
What if attempting to detect the presence of a virus to prevent its eventual
turn to cancer actually has dangers to the individual? Particularly in a situation where the rate of
cancer development from this virus is low?
For example, although nearly everyone who is sexually active will
acquire HPV, most virus types are not cancerous – and cancers are rare even in
those infected with high risk HPV types (HPV 16 and 18), requiring persistent
infection (Saraiya, 2013). There were an
average of approximately 32,000 new HPV-associated cancers identified between
2005 and 2009 in the US, of which 20,000 were identified in women (89% genital
cancers), while 12,000 were identified in men (78% were oropharyngeal ) (Saraiya,
2013).
Similar to other screening programs, we should be judicious
in use of societal resources to identify disease – it is difficult to weigh the
risks and benefits of screening because not all diseases are simple to detect,
and often our methods of detection are less than perfect – leading to many
individuals who test positive for a disease by a not-so-good screening method to initially believe they have cancer only to find out later it was a
false-positive result. This of course is
true in mammography where women often have lumps that require follow up
ultrasound or biopsy – which then pushes the woman into a limbo of fear of actually having breast cancer – only to find out later it was an
innocuous lump. Depending on the type of
lump found, some women undergo lengthy periods of heightened screening– leading to
anxiety and greater exposure to ionizing radiation – however this screening is
of great benefit when the risk of disease is high.
While early identification and treatment of disease are
important goals for our health care system, the actual ability of providers and
detection methods to deliver this result is often limited by the lack of
research and technology to accurately detect the disease. In the case of HPV there are immunizations that prevent
infection, however evidence is not yet available that these vaccines are effective
in those who are already infected – this is one reason why
the immunization focus is on youth who are not yet sexually active- it is hoped
that most infections with HPV 16 will be prevented in the future, thus eliminating risk of
cancer from this infection. With
continued research we will accumulate efficacy data from immunization. Hopefully someday we will also better understand how to prevent cancer in those with acquired HPV infection
and also have better methods for early identification of the infection before the cancer occurs.
References
& Links used to prepare this summary:
