Dr. Gabe Mirkin's Fitness and Health E-Zine
April 15, 2012
Update on Genital Warts and Cancer Risk
Men and women who have had genital warts are at
increased risk for cancers of the anus, vulva, vagina, cervix,
penis, skin (non-melanoma), head and neck, smoking-related
cancers, Hodgkin and non-Hodgkin lymphoma (J Infect Dis., May 1,
2012;205 (9), published online March 15, 2012). HPV causes
almost all cases of cervical cancer, most cases of anal and
penile cancers, and many vaginal and vulvar cancers.
MOST PEOPLE WITH GENITAL WARTS DO NOT DEVELOP CANCERS.
Fewer than five percent of the 49,000 people with genital warts
developed cancers over 30 years of follow-up. However, men with
genital warts had 21 times increased risk for anal cancer. One
percent of those with genital warts developed non-melanoma skin
cancer.
GENITAL WARTS ARE CAUSED BY HPV. There are more than 150
different Human Papilloma Viruses (HPV). Infection with one
type of HPV makes you immune to that virus so that once you clear
that virus, you are not likely to ever become infected with that
specific virus again. However, being infected with one type of
HPV does not protect you from developing any of the other types.
So you have the potential to become infected 150 times with 150
different HPV.
Most people clear a specific HPV within 6 to 9 months
of becoming infected. However, some people do not clear these
viruses and chronic infections with some HPV cause cancer.
HOW COMMON IS HPV? HPV is the most common sexually
transmitted disease. Your risk for acquiring HPV can be as high as
15 percent per sexual contact. More than 90 percent of sexually-
active people have been infected with HPV, and more than 50
percent of people infected with HPV have more than one HPV virus
(The Journal of Infectious Diseases, published online Nov. 4, 2011).
NOT ALL HPV VIRUSES CAUSE CANCERS. Genital HPV are
classified as low-risk and high-risk for causing cancers. Low-
risk HPV types (6, 11, 42, 43, 44, 54, 61, 70, 72, and 81) are
virtually never found in cancers. High-risk HPV types (16, 18, 31,
33, 35, 39, 45, 51, 52, 56, 58, 59, 68, 73, and 82) have been
found in cancers of the cervix, vagina, vulva, anus, and penis.
More than 80 percent of cervical cancers are caused by types 16,
18, 31, and 45. The two vaccines against HPV available today,
together, protect a person from infection with the four types of
HPV that cause the most cervical and anal cancers, but they do not
protect a person from infection with the remaining HPV viruses.
WHY MOST PEOPLE INFECTED WITH HPV DO NOT DEVELOP CANCERS:
Most infected people clear HPV from their bodies in 6 to 12
months. Continued exposure to new partners brings new infections
with new viruses. The more contacts you have, the more viruses you
acquire.
We do not have strong data to explain why some people
clear HPV from their bodies while others continue to be infected.
We do know that 6.9 percent of North Americans, 14 to 69 years of
age, are now infected with HPV in their mouths and that the more
cigarettes you smoke, and the more sexual partners you have, the
more likely you are to carry these viruses (JAMA. 2012;307(7):693-
703). Having infections with other germs increases cancer risk.
For example, being infected with chlamydia as well as HPV
increases cancer risk (Cancer Epidemiol Biomarkers, published
online October 12, 2011).
WHAT YOU SHOULD DO IF YOU ARE INFECTED WITH HPV: The vaccine
against HPV is totally ineffective if you already have those
specific HPVs. However it can help protect you against the
viruses that you have never had. Those who are infected with HPV
should do everything they can to help strengthen their immunities
to help it clear the virus from their bodies. The following steps
have not been proven to protect you against HPV, but they have
been shown to strengthen your immunity and to help protect you
against certain cancers, heart attacks and premature death:
* exercise,
* eat lots of fruits and vegetables,
* treat any other infections
* limit the number of sexual partners,
* do not smoke,
* do not take more than two alcoholic drinks a day,
* restrict sugared drinks and foods with added sugars,
* restrict red meat,
* restrict fried foods
* avoid overweight
FOR MY PREVIOUS REPORTS ON HPV INFECTIONS, see:
http://www.drmirkin.com/public/ezine020512.html
http://www.drmirkin.com/public/ezine112011.html
