Preventing cervical cancer may be the last thing on the mind of the average 11-year-old girl. But by getting vaccinated for human papillomavirus, or HPV, the virus that causes nearly all cases of cervical cancer, a girl reduces her lifetime risk of developing the disease by 70 percent, studies suggest.
The vaccine, called Gardasil and made by Merck, protects against the two types of HPV — 16 and 18 — responsible for most cervical cancers, the second leading cancer killer among women worldwide. It also immunizes against HPV 6 and 11, the types of the virus that cause 90 percent of genital warts, which are not life-threatening but can be distressing and difficult to treat.
The federal Advisory Committee on Immunization Practices recommends vaccinating girls between the ages of 11 and 12, and as young as 9 at the discretion of doctors. It also advises that girls and women ages 13 to 26 receive the vaccine if they have not yet been immunized. But the vaccine is controversial, and only 24 percent of eligible girls and women have gotten at least one of the three recommended doses.
One reason for the controversy is that the vaccine is relatively new. The Food and Drug Administration approved it in 2006, and this leaves some parents, and doctors, questioning its long-term safety and efficacy.
“Studies have been done on fewer than 2,000 girls ages 10 to 15, and to know if a vaccine is safe, millions of people have to get it and have a chance to report any adverse events,” said Dr. Diane Harper, director of the Gynecologic Cancer Prevention Research Group at Dartmouth Medical School. “It’s a public health experiment, but that’s the nature of vaccines.”
Proponents counter by pointing to Gardasil’s track record. An estimated eight million girls and women in the United States have received one or more doses of the vaccine, with fewer than 7 percent reporting serious side effects — about half the rate for vaccines over all.
“There’s six years of safety data that shows no long-term risks, and that’s the same timeframe for other recently recommended vaccines,” said Dr. Mark H. Einstein, director of clinical research in the gynecologic oncology division of Albert Einstein College of Medicine in New York.
Safety issues aside, some people oppose the vaccine because they fear that its use will encourage promiscuity. Or they have religious objections to vaccines, or argue that the government has no right to mandate its use, as some states have tried to do.
With or without the vaccine, many teenagers are already sexually active. A recent government study found that one in four girls ages 14 to 19 has a sexually transmitted disease. And one in four American girls and women ages 14 to 59 is infected with HPV, according to the Centers for Disease Control and Prevention. “This vaccine is a preventive health measure, not a sex education measure,” Dr. Einstein said. “From a science standpoint, it completely makes sense to vaccinate girls against HPV.”
The vaccine is being studied for use in boys and men, too.
“We don’t have widespread vaccination of women, so immunizing men may help protect those women who aren’t vaccinated,” said Dr. Kevin Ault, associate professor of gynecology and obstetrics at Emory University Medical School in Atlanta. It would also protect men against genital warts, which they get at a higher rate than women, and may immunize against relatively rare HPV-related cancers of the penis, anus, neck and head.
Most HPV infections clear up on their own, but those that persist, usually for five years or longer, increase a woman’s risk for developing precancerous cervical lesions. Pap tests, a routine part of a gynecological exam, usually detect these precancers, which can be treated so they do not develop into cancer. Still, 11,000 new cases of cervical cancer are diagnosed in the United States every year, most in women who haven’t gotten regular Pap tests, but some in women whose Pap tests didn’t detect precancerous cells.
Fortunately, cervical cancer is slow-growing.
“Usually the time to progression from a premalignant lesion to an invasive cancer is about 10 years,” said Dr. Teresa Diaz-Montes, gynecologic oncologist at Johns Hopkins Medical Center. When caught early, which is usually the case in the United States, cervical cancer can often be treated and cured by a simple or radical hysterectomy. Survival rates are high. “If the tumor is confined to the cervix, the five-year survival rate will be 80 to over 95 percent,” Dr. Diaz-Montes said.
And women can improve their chance of survival by getting treated by gynecologic oncologists rather than general gynecologists, studies show.
“Cervical cancer is not as common now as it was in the past because of Pap tests, so it’s important to be seen by a gynecologic oncologist because these are the specialists trained to treat this disease,” Dr. Diaz-Montes said. She advises women to look for a physician who sees a high volume of patients that need the same type of treatment they require.
Still, 3,700 women die from cervical cancer in the United States every year. Experts say that doesn’t need to happen.
“By getting vaccinated early and having regular Pap tests, and HPV tests when her health care provider recommends them,” Dr. Einstein said, “a woman has the best chance of preventing what is by far one of the most preventable cancers we have.”
By CAROL WEEG
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