Human Papilloma Virus/Gardasil Vaccination/Cervical Cancer
Human Papilloma Virus (HPV) has long been recognized as a link to causing cervical cancer. Many different subtypes of HPV have been discovered, and to this date, 15 subtypes are known to predispose women to cervical cancer. They also can predispose to vaginal, vulvar, anal, and penile cancer. HPV is quite common. It is estimated that 80% of sexually active people have HPV and the first act of sexual activity for any woman is likely to expose her to HPV. Some estimate that 6 million new cases of genital HPV are diagnosed annually in the U.S. Genital HPV can be completely asymptomatic, showing up only on a Pap smear, or they can cause genital warts. HPV can also lead to some vulvar discomfort in certain women, although this is less likely.
The High-Risk subtypes of HPV are numbered, and to date, the liquid-based Pap smears can check for 13 of these subtypes. ACOG (The American College of Obstetrics and Gynecology) has suggested that women 30 and over be tested at least every 3 years for HPV to improve the sensitivity of the Pap. Most insurance companies will pay for testing for women younger than this. The Low-Risk subtypes are generally not tested, but they can be if desired.
The Gardasil Vaccine supplied by Merck will offer almost 100% protection against 4 strains of HPV. These include Types 16 and 18, which are High-Risk HPV subtypes, and types 6 and 11, which are Low-Risk subtypes known to cause warts and recurrent papillomatosis in infants and children exposed during birth. These papillomas are being found in the oral areas in increasing numbers by ear, nose, and throat physicians. Although the vaccine doesn’t cover all the viral subtypes, it covers those that are most common, by protecting against 70% of cervical cancer and 90% of genital warts. Therefore, it does not completely eliminate the risk of cervical cancer, but it reduces the risk, especially for girls who have never had sexual activity. If one has already been exposed to one of these subtypes, it will not offer protection against it. To make an impact on cervical cancer, we must be proactive in vaccinating young girls prior to sexual activity. However, even if already sexually active or found to have HPV, we still advise vaccination in case one has not yet been exposed to these particular strains.
The vaccine has been used in Europe for at least 5 years prior to its use in the United States. To date, over 26 million doses of Gardasil have been given worldwide, and 16 million in the U.S. since June of 2006. Most side effects include some pain and inflammation at the injection site. Other events have included dizziness and fainting. To date, Merck has found no safety issue with this vaccine after reviewing all reports of adverse events. They participate in the U.S. Food and Drug Administration and Centers for Disease Control and Prevention adverse event reporting system.
The vaccine is administered as a 3 part series, with the first being given after it is deemed safe to do so, followed by the second one at 2 months and the third at month 6. This is similar to the Hepatitis B series which is required by the State of Texas. (Incidentally, Hepatitis B is contracted by sexual activity and IV drug use.) Currently, the vaccine is FDA-approved for girls and women ages 9 to 26, and currently, we find that most insurance companies will pay for vaccination. Merck is presently working on FDA approval for women ages 27 and over, and hopefully, the FDA will approve vaccination for young men as well. Personally, if I had a son, I would choose to vaccinate him even though insurance would not pay for this. It is more difficult to see the “end-point” of vaccination in boys and men as they do not undergo early cancer screenings with Pap smears as women do, and penile cancer generally occurs later in life. For these reasons, the FDA may never approve vaccination in boys and men, however, in my OPINION, the vaccine is not harmful and will be helpful to cancer prevention in men and women.
Pap smears for cervical cancer screening should be offered as soon as a woman becomes sexually active. The screening is more sensitive with liquid-based Paps, such as Thin Prep, and with the addition of HPV High-Risk DNA Probes. Should the test be abnormal, especially with a positive HPV DNA Probe, then further follow up with a more magnified view of the cervix, called a Colposcopy, can be done. Biopsies of any abnormal areas can be taken, and if pre-cancerous cells are found, a further more extensive biopsy called a LEEP or LLETZ can be offered to remove the abnormal tissue. Alternatively, young women may choose to have a modified type Colposcopy called a Pap Sure test at the time of the annual visit. It is done simply after the Pap Smear, and the cost is under $50 at this time. This increases the sensitivity of the Pap Smear and aids in the detection of HPV and pre-cancerous cells. If abnormal, more in-depth magnification with a formal Colposcopy is scheduled for the next office visit.
For more information about these and other related topics, check out the following websites: The ACOG website allows one to view information on any gynecology topic.