For decades, the cancer community has shared a dream: What if we could develop a vaccine for cancer? In the case of cervical cancer, that hope has been fulfilled. Researchers have developed two different vaccines that prevent cervical cancer by attacking its primary cause: the human papillomavirus (HPV). HPV infections spread through sexual contact and can lead to cervical dysplasia, or abnormal cervical cells, and then to cancer.

UAB physicians have been involved in clinical trials studying both vaccines. Gardasil® was approved by the Food and Drug Administration in 2006 and is now available to patients. Cervarix®, a similar drug, is awaiting FDA approval. In Phase III studies, Cervarix® was 90 percent effective in preventing precancerous lesions caused by HPV 16 and HPV 18, two virus strains responsible for 70 percent of cervical cancer cases.

The long-term benefits of these vaccines are inconclusive but promising. "Gardasil® has been out for less than two years, but the time between when a woman gets an HPV infection and when she develops cancer is about 20 to 25 years," says UAB gynecologic oncologist Warner K. Huh, M.D. "So it's going to take us that long-if not longer-to figure out whether we're going to appreciably decrease cervical cancer rates in this country."

But Dr. Huh notes that as more women become vaccinated, it will be easier to evaluate the effectiveness of Gardasil®. Still, this will be a slow process, he predicts. "It's probably going to be another eight to 10 years before an appreciable number of girls in this country get vaccinated."

In the short term, however, the benefits to women are still considerable. In addition to preventing the strains of HPV that cause cancer, the vaccines also prevent strains that lead to genital warts and other related diseases. A major multinational study of Gardasil® that followed 18,000 women over a three-year period saw abnormal Pap smears reduced by up to 40 percent; the number of biopsies and referrals to further evaluate abnormal screening results fell by up to 20 percent. That means more women are spared the cost, physical discomfort, and anxiety associated with diagnosing and treating abnormal cervical cells.

"One in three women in this country will have an abnormal Pap smear in their lifetime," Dr. Huh says. "So if I tell a patient, ‘You may have a 40 percent reduction in your risk of an abnormal Pap smear'-that's a huge benefit."

Caperton Gillett