Background information on HPV:
HPV or human papilloma virus exists in more than 70 different types. These can lead to cervical cancer, anal cancer, warts (on any part of the skin, even hands), along many other types of cancer.
The most common HPV infection is around the genitals, but it is really hard to realize you have the disease especially when it's possible to have no symptoms.
Some important facts about HPV:
- HPV infection can be spread from one person to another through sexual contact involving the anus, mouth, or vagina. You can spread the warts even if you do not see them.
- You may not see warts for 6 weeks to 6 months after becoming infected. You may not notice them for years.
- Not everyone who has come into contact with the HPV virus and genital warts will develop the disease
- HPV and Cancer
HPVs are an infection of the epithelial cells, which as we have learned from class are layers that are the lining of the inside and outside surfaces of our bodies. Because they are not blood related, HPV infection can not metastasis to another part of the body.
When it has entered the cell, the virus starts making proteins and two of these proteins which are made by high-risk HPVs cause the cell to grow uncontrollable and avoid cell death (Hallmarks of Cancer!). Although they can be eliminated by the immune system, sometimes they aren't recognized and therefore not destroyed.
Research shows that it make take up to 10 to 20 years from the time of the infection to when a tumor actually forms.
* It does not always lead to cancer.
Discussion:
One of the articles, written in 2008, discusses the findings of Dr. Maura Gillison of Johns Hopkins University. She has come to the conclusion that roughly about 5,600 cancers of the throat, tongue, and tonsils all originate from HPV. As this study has become more popular, scientists have gone back through their records and found that HPV can be connected to oral cancers dating back to 1973.
Because of the correlation between HPV and cancer, many people were pushing for the vaccine to 1) by law be administered to all young teens as early as 12 yrs old and 2) for there to be a vaccine that men could take to help them fight off this disease. While it is not a law yet, there is a vaccine, Gardisil, that men can have administered for protection. The CDC believes that the HPV vaccine should be included in a checkup when boys get all their other vaccinations. However, there is major controversy regarding this vaccine. The video below gives a televised interview which talks more about the vaccine and how many people are hesitant and why.
Fig. 1
Prevalence of
human papillomavirus (HPV) DNA in tumor tissue of oral cancer case
subjects. A) By sex; B) by age at diagnosis;
and C) by tumor site. Gray bars 4 total HPV
DNA; black bars 4 HPV type 16 DNA; and hatched bars 4 HPV type 6 or type
11 DNA.
Includes interviewed and noninterviewed case
subjects. HPV type 16 DNA tumors (n 4 41) included 31 tumors with only
HPV type
16 DNA and 10 tumors with HPV type 16 DNA and
one or more other HPV types (seven with HPV type 6 or type 11 DNA, one
with
HPV type 11 and HPV type 31/33/35 DNA, one
with HPV type 6 DNA and an unknown HPV DNA type, and one with unknown
HPV DNA type).
Two tumors contained only HPV DNA that could
not be classified as to a specific type. Not included in C are two
tumors arising
in the uvula and two tumors for which the
site was unknown
The figure above gives a more quantitative view of just how much HPV is connected to oral cancers and which of the 4 types is responsible (6, 11, 16, and 18[only included in the total]). From Table A we can see that men and women are roughly equal in having the disease, which confirms that men need to realize that they too can greatly be affected by HPV. Table C shows how HPV is overall, greatly linked to oral cancers.
Conclusion:
I thought that the articles were very interesting, especially when it closely related to some of the lessons we learned this week. The fact that even though this seems like a recent study, scientists have been able to go back and trace HPV through the years and link it to oral cancer cases all the way back to the 70's was really intriguing. The video interview struck home with me because, living in Texas, I am aware about Rick Perry's idea of making the vaccine mandatory and the controversial scandal it created. Many parents were outraged, as it states in the interview, because they were scared that it would promote teen promiscuity. Although that may be a reasonable argument, I always felt that if the benefits are greater, is it really so bad to make this vaccination required by law. So my first question is more of a political question then a scientific question (and you don't have to answer), if this vaccine is known to aid in the prevention of this disease and is FDA approved and CDC recommended, should this vaccine be added to the list of required vaccinations in the hopes of preventing HPV and the cancers it causes? (Don't mean for this to turn into a moral war zone, more to see whether people believe this is still something that should be a private issue between family members or because of the potential benefits should become regulatory)
My other thought when reading this was if the immune system has the ability to recognize the tumor and destroy it, how does HPV hide itself from being detected, allowing it to continue growing?
http://www.msnbc.msn.com/id/22956090/ns/health-oral_health/t/hpv-increasingly-causes-oral-cancer-men/#.T5Hx7o7DPWJ
http://www.cdc.gov/hpv/vaccine.html
http://jnci.oxfordjournals.org/content/90/21/1626.full
http://www.cancer.gov/cancertopics/factsheet/Risk/HPV
