In June, the Food and Drug Administration approved a vaccine to prevent infection with several strains of the Human Papilloma Virus (HPV). Why is this important? HPV is the name of a group of viruses that include over 100 types. More than 30 of these can be passed through sexual contact and many have been known to cause abnormal pap smears and cervical cancer.
HPV is very common and approximately half of sexually active women become infected at some time in their lives. Fortunately, most women’s immune systems clear the virus and no health problems develop. However, some types of HPV can cause cervical abnormalities that can sometimes progress to cancer. The usual screening for cervical cancer–the pap smear–has been remarkably effective in reducing cervical cancer in the US. Cervical cancer rates have decreased 75% in the past 50 years due to regular pap smear screening. Sadly, in spite of this, about 10,000 women will develop cervical cancer this year and 4,000 will die from their disease. In the US today the vast majority of women with cervical cancer have not had a pap smear in the previous 5 years! In fact, worldwide almost 500,000 cases of cervical cancer have developed, mainly in countries where health screening is not possible for most women.
Research in the 1970’s turned our attention to HPV as the causative agent in cervical cancer. Additional work identified the high-risk types of virus associated with cancer and its precursors. For the past 10 years gynecologists have been using the presence of the virus as a helpful tool in managing abnormal pap smears. Thirteen subtypes of HPV have been specifically associated with cervical abnormalities and cancer. Further research has resulted in the development of a vaccine.
The currently available vaccine “Gardasil” will be joined by a competitor in 2007. Both are effective against two types of HPV, 16 and 18. These account for 70% of cervical cancers and abnormal paps. It has been 100% effective in preventing infection with HPV over 4 years. In unvaccinated women, 2-3 out of 100 developed abnormal pap smears over the same 4 years. This is remarkable success and the antibody levels appear to show long-term immunity!
“Gardasil” also provides immunity to HPV types 6 and 11 which are responsible for 90% of genital warts. These are skin lesions of the genital area, which, though not dangerous, do cause discomfort, irritation, and distress and also result in significant cost in treatment and doctor’s office visits.
The CDC and the American College of Obstetrics and Gynecology have recommended that the vaccine be promoted to be included in routine vaccine schedules. The primary group has been selected to be 11-12 year-old females. At this time no recommendations have been made for males as the efficacy studies have not been completed. It is also recommended that sexually active women aged 13-26 years be vaccinated. This is NOT used as a treatment for abnormal pap smears! The intent is to provide immunity prior to first sexual contact for maximum effectiveness.
The vaccine is given in three doses spaced at 1, 2, and 6 months. It is expected that this will be included in the Vaccines for Children Program. Though most insurance companies pay for vaccines included in the above program, it may take a while for them to get up to speed and it should be remembered that many plans have high deductibles for preventative services. The vaccine is expected to cost about $120 per dose.
As with all new therapies, it is expected that HPV vaccine will take some time to be incorporated into the routine care of young women. It took a number of years for both the chickenpox (Varicella) vaccine and Hepatitis B vaccine to take root as a part of routine care, but the advantages have been shown to be much greater than the cost. We may have a longer time to wait before we see a decrease in cancer cases, since there is a 5-to-20-year interval between infection with HPV and precancerous or cancerous changes on the cervix. However, in our office, the majority of patients seen in consultation for abnormal pap smears are under 30 years of age. They must go through an office procedure called colposcopy and possible treatment, plus several years of frequent pap smear follow-up. The anxiety and inconvenience are not insignificant and the cost is much more than the vaccine.
All of us will be happy to discuss the vaccine, HPV, and how you can help you and your daughter understand this new and exciting preventative treatment for a cancer that was once the most common of female cancers.