If there were a vaccine that could prevent cancer, why wouldn't you get it?
Gardasil, a new vaccine that can prevent developing the human papillomavirus, is just such a vaccine. Human papillomavirus, known as HPV, can cause most cervical cancers, most cancers of the vagina and vulva, and genital warts. This virus is the only one that is shown to lead to cancer. The vaccine, which won federal approval June 8, 2006, is the only vaccine that can protect against cancer.
The vaccine is approved for 9- to 26-year-old girls and women. While it is almost always females who get HPV, the virus is spread by both men and women during sexual contact. And both men and women are susceptible to genital and rectal warts, which can lead to cervical changes and abnormal Pap smears in women. Most scientific studies have found that HPV infection is responsible for 90 percent of the cases of cervical cancer.
The best way to protect someone is to vaccinate them before coitus, which is why the vaccine is recommended for such young girls.
Developed, clinically tested and marketed by Merck & Co., the vaccine was discussed by Dr. Joseph Rodriguez at a recent Brown Bag lunch lecture at St. Luke's Wood River Medical Center, Thursday, Dec. 7. Rodriguez, a board certified obstetrician/gynecologist, offers the vaccine, though it must be pre-ordered. As well, Wood River Family Medicine in Hailey and Ketchum is already dispensing the vaccine, as is South Central District Health in Bellevue.
There are three main risk factors to getting cervical cancer and very definite ways to avoid it, unlike most cancers, Rodriguez said.
Those risk factors are how young a woman is when she begins being sexually active, how many partners a woman has and if she is a smoker.
"The biggest is smoking," he said. "Tar and nicotine—the toxins found in cigarettes—concentrate in the cervix and weaken the immune system. For every one cigarette smoked that's one for the lungs and the equivalent of four for the cervix. Smoking—that's the big modifiable risk. There is a huge association with smoking and cervical cancer. So, don't smoke."
Using protection and having regular Pap smears has helped to decrease the number of women who have the disease in the U.S.
"Worldwide it is the first or second cause of cancer in women, breast cancer being the other," Rodriguez said. "Fifty percent of women who have cervical cancer have never had a Pap. Thirty percent have not had one in five years. It's really a shame. There's no reason not to have a Pap."
Women should get an annual Pap smear within three years of having vaginal sexual intercourse or no later than 21 years of age.
In Idaho, some insurance companies will cover a portion of the cost for preventative vaccines. Many states do not. The vaccine is a series of three given over six months—two and six months after the first shot.
"The reason for hitting girls at the age of 9 is that we're looking at preventing infection. It's not a treatment for cancer," Rodriguez said. "But it's a personal decision. I think it's important for the family to have a frank and open discussion about sexuality, diseases and pregnancy. Make sure she understands the risks of having sex."
Because the vaccine is so new there are no long-term assessments. What the scientists do know is that for at least two years there is protection. For women already sexually active there are also no statistics. But, Rodriguez said, "Why not (vaccinate)? It could help bolster the immune system. It seems to practically make sense."
In her practice, Certified Registered Nurse Practitioner Julie Watson at Wood River Family Medicine spends a lot of time talking to young girls about sexually transmitted diseases.
"I think the vaccine is a great thing. People are concerned about young women getting Gardasil, that maybe they'll become sexually active, but if this can prevent 70 to 75 percent of cervical cancers, and 90 percent of genital warts, why not?
"Also, people think that if we're doing something that is sex-related, people will be promiscuous. That's the wrong way of looking at it. You can get HPV from having just one partner."
In clinical studies, Gardasil prevented 100 percent of HPV genetic type 16 and 18 related cervical cancer in women not previously exposed to the relevant HPV types. Type 16 is among the most virulent and is associated with half of all cervical cancers. The other two types that Gardasil protects against are type 6 and 11. These are associated with genital warts.
The efficacy was evaluated in four placebo-controlled, double-blind, randomized Phase II and Phase III clinical studies, which together evaluated 20,541 women aged 16 to 26 years. Study participants were followed for up to five years after enrollment. There were no documented side effects.