Taking a Closer Look at HPV
by Marta Tarbell
Oct 17, 2011 | 1738 views | 0 0 comments | 18 18 recommendations | email to a friend | print
Studies – as well as common sense – suggest that most parents underestimate the extent to which their teenagers are sexually active.

An understandable tendency, but also one that underlies, perhaps, some parents’ resistance to the much-touted vaccine offering pre-sexual girls future protection against the increasingly prevalent Human Papilloma Virus, now present in 93 percent of genital cancers.

HPV, one of the most common virus groups in the world today, is carried by more than 80 percent of all sexually active people, and is now so widespread that it is referred to as the “common cold” of sexually transmitted infections.

Every year in the U.S., there are more than 6.2 million new HPV infections in both men and women, according to the Centers for Disease Control and Prevention. Their most worrisome side effect: The fact that ten percent of these infections will develop into persistent dysplasia and possibly cervical cancer in women. (Although HPV infection is a cause of nearly all cases of cervical cancer, most HPV infections do not cause the disease.)

HPV-triggered oral infections are now on the rise, as well, to such a degree that, in the U.S., research indicates HPV could replace tobacco as the main causative agent for oral cancers.

HPV is an infection caused by sexual contact, generally during vaginal, anal or oral sex. When a person carrying HPV engages in skin-to-genital contact with a sexual partner, the virus is easily transmitted. Unfortunately, most people who carry the virus don’t know they have it.

In the cervix, HPV can trigger cell alterations, leading to the development of pre-malignant tumors that can cause cancer.

A high-risk strain of HPV is considered the most important risk factor in the development of cervical cancer, which is on the rise, in resource-poor countries, from an estimated 500,000 new cases of cervical cancer worldwide, and 270,000 deaths, in 2008. Although Pap smears have reduced the incidence of cervical cancer in the developed world, that same year saw, in the U.S., 11,000 cases (with 3,900 deaths) of cervical cancer.

Studies indicate that both drinking alcohol and smoking help promote HPV invasion: Alcoholic beverages contain ethanol alcohol, a known inhibitor of Protein 53, a tumor-suppressor protein, and the carcinogens in tobacco have been shown to damage cell DNA, the precursor event to malignancy.

Combine tobacco and alcohol with HPV and the epithelial cells lining body cavities (the mouth and genitals most particularly), and you have a formula for the development of oral cancer. A recent study by the Johns Hopkins Oncology Center found a strong link between HPV and oral cancer, and researchers say that in the U.S., HPV may soon replace tobacco as the main causative agent for oral cancer.

While the majority of the nearly 200 known types of HPV cause no symptoms in most people, some types cause warts, while others can – in a minority of cases – lead to cancers of the cervix, vulva, vagina, anus, head, neck, tongue, tonsils and throat.

Because HPV is so prevalent, vaccinating for HPV is effective only before recipients become sexually active. To begin the war against this potentially deadly disease, health organizations including the American Academy of Pediatrics, the American Cancer Society, the federal Centers for Disease Control and Prevention and the American Academy of Family Physicians support vaccinating adolescent girls for HPV, endorsing the vaccine as virtually 100 percent effective in blocking the virus.

HPV AND CERVICAL CANCER

While critics charge that the HPV vaccine, linked to 49 deaths as of last year, is not as effective as its supporters contend, adherents say eradicating HPV could curtail cervical cancer, which every year kills more women than die in childbirth. That death rate is skyrocketing in developing countries, with estimates that more than 1 million women could die from cervical cancer every year by the year 2050 if HPV is not eradicated.

“You could say it is a developing epidemic of cervix cancer,” said International Agency for Research on Cancer Director Peter Boyle.

“But cervical cancer is one form of cancer where we can do something about it.”

MOST HPV INFECTIONS ARE ‘TEMPORARY’

Most HPV infections in young women are temporary, and have little long-term significance, with 70 percent of them gone within one year and 90 percent in two years, flushed out by healthy immune systems.

But when the infection persists, which it does in 5 to 10 percent of infected girls and women, there is high risk of developing precancerous lesions of the cervix, which can progress to invasive cervical cancer, over an average period of 15-20 years.

This timeframe provides many opportunities for detection and treatment of pre-cancerous lesions for women receiving adequate medical care, so that the progression to invasive cancer can be almost always stopped, by the application of standard prevention strategies.

But even when caught early, HPV-caused lesions often subject carriers to preventive surgeries that can lead to loss of fertility. Because HPV carriers are often asymptomatic, and because there is no FDA-approved HPV test for men, HPV exposure can lead to multiple and escalating health problems for both sexes.

HPV VACCINE SIDE EFFECTS

Right now, two HPV vaccines – Cervarix and Gardasil – help prevent infection with HPV types 16 and 18, the two HPV strains causing 70 percent of cervical cancer. In 2009, the CDCP reported that over 25 million doses of Gardasil, the predominant HPV vaccine recommended for females aged 9-26, were administered in the U.S. According to the Food and Drug Administration’s Vaccine Adverse Event Reporting System, there were an average of 53.9 negative reactions per 100,000 vaccine doses; a second study found 772 serious problems identified in 23 million doses of vaccines, including 32 deaths – in both cases, relatively encouraging statistics. “I usually tell my patients that these serious events are tragic, rare and likely unrelated to the vaccine,” said Dr. Kevin Ault, associate professor of Gynecology and Obstetrics at Emory University, of the negative reactions.

The American Society for Colposcopy and Cervical Pathology, which has educated thousands of clinicians about the risks of HPV and the Gardasil vaccine, was similarly supportive of the Gardasil response. “We based our education [program] criteria on data from the CDCP’s risk assessment,” said Dr. L. Stewart Massad, ASCCP’s Practice and Ethics Committees chair. He went on to acknowledge, however, that “certainly there are differences of opinion when it comes to how adverse events are. You have to balance the risk for each patient.”

According to the CDCP, Gardasil is a safe vaccine, with fainting its likeliest negative side effect; not surprisingly, Gardasil manufacturer Merck has declared the vaccine virtually side-effect free, saying reports of pain at the injection site are the most common complaint.

HPV VACCINE DOES NOT PROTECT FOREVER

But there remains one inarguable downside. “Perhaps the most important, currently missing ‘warning’ is that the vaccine may not be forever,” said Dr. Joseph Zanga, chief of pediatrics at the Columbus Regional Healthcare System in Columbus, Ga.

“We know that it protects for five to seven years,” which could mean “that a girl getting the series [of three vaccines] at [age] 11-12 will enter the time of her most-likely sexual debut unprotected but believing herself to be.”

Zanga went on to point out that Gardasil does not prevent women from contracting HPV in every instance, and that routine Pap smears are still the best prevention against cervical cancer.

A Judicial Watch analysis of the FDA’s Vaccine Adverse Event Reporting System contends that Gardasil booster claims are disingenuous regarding the vaccine’s downside. “Although the number of serious adverse events is small and rare, they are real and cannot be overlooked or dismissed without disclosing the possibility to all other possible vaccine recipients,” said Dr. Diane Harper, director of the Gynecologic Cancer Prevention Research Group at University of Missouri.

While some HPV-infected people exhibit telltale genital and oral warts, most exhibit no symptoms, thus perpetuating the cycle of HPV infection unwittingly. Condoms are not 100 percent effective in protecting against HPV transmission, mostly because the virus is contracted through any skin contact around the genitals, although the CDCP does emphasize that the use of condoms is linked to lower cervical cancer rates.

And while there is no research, to date, on sexual behaviors of vaccinated versus unvaccinated teenagers, research on the effects of making condoms available to teenagers has shown no evidence that condom availability leads to an increase in teens’ sexual activity.

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