HPV Vaccine And Cervical Cancer: Is it worth vaccinating?

Author：佚名 Source：none Hits：147 UpdateTime：2008-10-19 0:38:48


Over the past two years, the O-N-E L-E-S-S campaign for Gardasil, the new HPV vaccine to protect against cervical cancer, has brought discussion about the human papilloma virus to the forefront, shining new light not only on the vaccine itself, but also on the issues that surround it.

HPV is ubiquitous. Nearly 50% of sexually active people will have HPV at some point in their lives. There are around 20 million people with HPV infections in the U.S., with 6.2 million new cases occurring every year. The most serious consequence of HPV infections is cervical cancer, yet public knowledge about HPV is poor -- less than 50% of women have heard about HPV and its link to cervical cancer.

It's crucial that the public gains more knowledge about HPV and cervical cancer, particularly in the present climate where the merits of the vaccine have been clouded by a political rhetoric. Information on the link between HPV and cervical cancer, how common the disease is and who gets it, detection methods, other effects of the disease, and the role and effectiveness of the vaccine have to be addressed. Examining these topics will help guide decisions as medical professionals recommend this vaccination to a whole generation of 11-12 year old girls, and perhaps boys in the future.

The relationship between HPV and cervical cancer: There are over 100 types of HPV. About 15 of them are "high-risk" types that cause cervical cancer. HPV infections are more common in the younger population, with nearly 75% occurring in the 15-25 age group. Most HPV infections are "silent" -- people who carry the virus don't know they have it and transmit it freely to their sexual partners. The good news, however, is that most of these infections are self-limiting, meaning that nearly 90% of them resolve on their own within 24 months without causing any problems. In a minority of people, however, the infections persist, either as a result of high-risk sexual behavior (such as multiple partners and unprotected sex), or weakened immunity because of smoking, stress, and long term use of certain medications like steroids. These factors can propel HPV infections to cause precancerous and cancerous lesions of the cervix. Over 99% of cervical cancers are caused by HPV. HPV infections are necessary, but not sufficient on their own to cause cervical cancer.

Pap tests and cervical cancer: A Pap test detects early changes in the cells of the cervix due to HPV or other effects, which if left untreated, may progress to cervical cancer. Fortunately, due to a well organized Pap test program in the U.S., the incidence of cervical cancer has dropped by 75% over the past 50 years. Therefore, for women who get regular Pap smears, the incidence of cervical cancer is low. Currently in the U.S., about 11,000 new cases of cervical cancer develop each year, and around 4,000 deaths occur from it. Even though one would wish that there were no cases of cervical cancers to reckon with, when compared to the number of HPV infections that occur each year, the ratio between HPV infections to cervical cancer is low. According to the American Cancer Society, four out of five women who died of cervical cancer did not have a Pap test in the previous five years. These numbers show that the Pap smear has been very successful in curtailing the incidence of cervical cancer in this country.