A significant drop in abnormal Pap test results happened after girls and women were given a vaccine to prevent cervical cancer, according to a researcher at the University of Alabama at Birmingham (UAB).
The findings show the vaccine, named GARDASIL, appears to prevent the development of cell changes that lead to cervical disease, the researcher said.
In testing GARDASIL reduced abnormal Pap test results by 43 percent compared to women not given the vaccine. The 43 percent reduction was for tests that found pre-cancerous changes called high-grade squamous intraepithelial lesions (HSIL) more than three years after women were given the vaccine.
GARDASIL reduced other abnormal Pap results, including milder pre-malignant cell changes, by 16 to 35 percent compared to women not given the vaccine.
While the findings are not definitive that GARDASIL prevents cancer, they do signal the vaccine will spare thousands of women a diagnosis of cell abnormality or malignant changes that may lead to more tests and possibly surgery, said Warner Huh, M.D., associate professor in the UAB Division of Gynecologic Oncology and the doctor chosen to present the data.
"Clearly the vaccine's benefits include something that can be appreciated by women and daughters fairly quickly," Huh said. "This is a positive first sign, and it will take many more years to know definitively if the vaccine prevents cancer."
The findings were presented March 10 at the annual meeting of the Society of Gynecological Oncologists held in Tampa.
The results are a compilation of three separate trials involving more than 18,000 women, ages 16 to 26, in the United States, Europe and Asia.
All test subjects had normal Pap smear readings at the start of the trial.