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Two medical experts debate HPV vaccinations

BY GUEST EDITORIAL | DECEMBER 05, 2011 7:20 AM

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Harper: Gather information and make your own choice

Direct communication and full information are necessary to make health-related decisions.

As a physician who routinely treats women and men with HPV-diseases, my experience includes having sat at the bedside of women dying of cervical cancer; having performed tens of thousands of colposcopies; having surgically treated pre-invasive HPV-related disease; having been actively involved in HPV cancer-prevention research for more than 20 years at the National Cancer Institute, Dartmouth, and University of Missouri-Kansas City; having served as the state director for the CDC Breast and Cervical Cancer Early Detection Programs; having served as a consultant to both Merck (which manufactures the HPV vaccine Gardasil, the one used by University of Iowa Hospitals and Clinics) and GSK (which manufactures the HPV vaccine Cervarix) on the vaccine trial designs as well as the phase-II and phase-III trials for FDA approval of both Gardasil and Cervarix; having served as a consultant to the World Health Organization; and having been an invited visiting professor to more than 70 countries about cervical cancer-prevention and HPV-associated diseases. So it's refreshing to see an editorial ("Recommend Pap smears, not vaccines" Nov. 29 The Daily Iowan) that does not shame or fear people into being vaccinated with Gardasil.

The current Pap-screening program in the United States has resulted in an average incidence of 8 per 100,000 cases of cervical cancer per annum. Black and Latina women have higher rates at 11.1 per 100,000 and 12.8 per 100,000. The very best that Pap screening can do is to reduce the incidence of cervical cancer to 2 to 3 per 100,000 women because of false-negative testing.

Ignoring Pap screening and making generous assumptions that Gardasil will last your whole life (for which there is no proof, only speculation), that the efficacy will remain at 100 percent for your whole life (again no proof, only speculation), that Gardasil will provide complete protection from HPV-16 and -18 and partial protection from HPV-31, and that every single female receives three doses on time, the lowest incidence of cervical cancer that Gardasil can achieve is 14 per 100,000 after 60 years of Gardasil use.

Making similar assumptions about Cervarix, but with the difference being protection against six of the cancer causing HPV types, the lowest incidence Cervarix can achieve is 9.35 per 100,000. Making similar assumptions about the monovalent Gardasil+5 vaccine that is being tested on women at the UI, the lowest incidence of cervical cancer achievable is 9.3 per 100,000 women.

Clearly, if one has to choose between Pap screening and vaccination, Pap screening is the way to detect early lesions so that these lesions caused by all 15 of the cancer causing HPV types can be treated and thus, cervical cancer prevented. Clearly, there is also a choice in which vaccine a woman may want if she chooses to add vaccination to her Pap screening program.

If you take a belts-and-suspenders approach and use both Pap screening and HPV vaccination, we have to go to modeling to see what the conjoined effect will be, because there are no real data. All cost-effective models published in a wide range of countries show that if the vaccine is given at 11 to 12 years of age and does not last for at least 15 years (over the period of time she is most sexually active and most at risk of HPV infection), there will be NO cancers prevented. The cancers will still develop, but now at older ages. If modelers make the assumption that the vaccines will last a lifetime without waning efficacy, then the number of cancers that could be prevented above what Pap screening is currently doing (not accounting for better outreach and access to screening and treatments) is so small that vaccination statistically does not lower the population incidence of cervical cancer over what Pap screening can currently do.

While many medical professional organizations recommend HPV vaccination as something to consider in your tool kit for cervical-cancer prevention, no professional organization mandates HPV vaccination. All organizations recognize that more than 95 percent of HPV infections never progress into a cancer and that Pap screening is absolutely necessary for cervical cancer early detection and treatment. Most organizations recognize that the HPV vaccines are a choice to consider for your cervical-cancer prevention program, like sprinkles on an ice cream cone — that is why they are recommended.

Everything done in medicine has both benefits and harms. It is your ability to gather information from many perspectives to be able to weigh the value of the benefits and harms of HPV vaccination for you that is most important.

Diane Harper, M.D., M.P.H., M.S., is a professor of medicine and the director of the Gynecologic Cancer Prevention Research Group at the University of Missouri-Kansas City.

Stapleton: Discouraging HPV vaccine 'irresponsible'

The recent DI editorial titled "Recommend Pap smears, not vaccines" provides misleading information that may discourage UI students and other readers from receiving a vaccine that could save their lives. As a physician who has treated young women with cervical cancer, a scientist who has conducted research on HPV vaccines, and a father of two daughters, I find the DI's suggestion irresponsible.

Pap smears are a diagnostic test, not treatment. The editorial correctly points out that Pap smears are safe and important in identifying pre-cancerous lesions of the cervix. However, despite the widespread availability of Pap smears, 12,000 women are diagnosed with and 4,000 women die of cervical cancer each year in the United States. Several excellent studies show that women screened by Pap smears are six to 10 times less likely to develop invasive cancer of the cervix.

Unfortunately, 15 percent of women never have a Pap smear, and far more women do not have regular Pap smears. Thus, many pre-cancerous lesions remain undiagnosed until cancer has begun. In addition, Pap smears frequently give false-negative and false-positive results (i.e., they miss pre-cancerous lesions or they falsely identify lesions as pre-cancerous). False negatives occur in 10 percent to 29 percent of cases, and women with false-negative results will not know to seek preventative therapy for their pre-cancerous condition. Finally, the widespread availability of Pap smears has clearly not eliminated cervical cancer in the United States.

So how can we reduce this preventable cancer, which is diagnosed in 30 women every day in the United States? We should encourage women to have Pap smears AND receive the HPV vaccine. The DI editorial suggests that Pap smears alone are sufficient. However, the editors failed to mention the following key points:

First, cervical cancer is linked to HPV infection in more than 99 percent of cases. A woman simply does not get cervical cancer if she is not infected with a cancer-causing strain of HPV. Second, Pap smears detect HPV infection as "pre-cancerous lesions." Large clinical studies that included more than 16,000 women show that the two HPV vaccines prevent virtually all of the pre-cancerous lesions and HPV infections caused by HPV strains contained in the vaccine.

No one advocates using the vaccine and abandoning good, preventative women's health-care, which includes Pap smears. However, the HPV vaccine adds another layer of protection to Pap smears and maximizes efforts to reduce cervical cancer. Furthermore, by preventing pre-cancerous lesions, the vaccine will reduce the number of invasive procedures (i.e. colposcopy, LEEP) and reduce the frequency of women being told that they have "pre-cancer." In addition, HPV vaccination will decrease the need for the intense medical follow-up required for abnormal Pap smears, including biopsies. These biopsies have risks, including potential problems with future pregnancies.

Finally, the DI editorial quotes Dr. Diane Harper as the sole expert used to defend its editorial "Recommend Pap smears, not vaccines." Based on the editorial, I assumed that Dr. Harper would not prescribe the HPV vaccine to her patients. However, I e-mailed her to ask that question, and she informed me that "Yes, I offer both Gardasil and Cervarix to parents and to women. At least half of the young women opt to have protection from the 20 percent chance of abnormal Pap test."

Her response is neither consistent with the idea that HPV vaccines should not be used nor consistent with recommendations of U.S. government health organizations, including the FDA and CDC, or with professional organizations including the American Academy of Pediatrics, the American Academy of Family Physicians, the American College of Obstetrics and Gynecology, and the American College of Physicians. These professional organizations convened panels of people with expertise in a wide range of relevant areas including women's health, pediatrics, public heath, infectious diseases, immunology, cancer, vaccinology, nursing, and statistics. The panels review the primary data from the research studies of the HPV vaccines and make recommendations based on their consensus conclusions. All of these organizations recommend use of the HPV vaccine. Relying on a single source to support one's own opinion may be dangerous for your health.

In conclusion, a combination of good women's preventative health-care (including diagnostic Pap smears) and the preventative HPV vaccine is the best way to reduce the risk of cervical cancer. If a DI reader has any questions regarding the HPV vaccine, I encourage her or him to review the recommendations of the Advisory Committee on Immunization Practices. If anyone would like to discuss HPV vaccine issues with me further, I would be happy to do so.

Jack T. Stapleton, M.D. is a medical professor in the University of Iowa's Division of Infectious Diseases.


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