Cervical Cancer Vaccine Shows Promise for Preventing Other Cancers in Women

< June 7, 2006 > -- A new study shows that a vaccine developed to prevent cervical cancer could also be helpful in preventing vaginal and vulvar cancers associated with human papillomavirus (HPV).

The research results were presented at the annual meeting of the American Society of Clinical Oncology (ASCO) earlier this week in Atlanta.

According to Finnish researchers, the GardasilTM vaccine was 100 percent effective against vulvar and vaginal precancerous lesions caused by HPV types 16 and 18, and was 81 percent effective against all HPV types.

HPV is responsible for virtually all cases of cervical cancers and is present in 80 percent of the 6,000 cases of vaginal and vulvar cancers diagnosed in the United States each year. HPV is spread by sexual contact.

The virus also causes precancerous and benign cervical lesions and genital warts, and may be associated with some anal and oral cancers. An estimated 20 million men and women in the US are infected with HPV but, for most, the virus shows no symptoms and goes away on its own.

Cervical cancer is the second most common malignant disease in women globally, causing an estimated 290,000 deaths worldwide each year. In the US, some 3,700 women will die from the disease.

Although less common than cervical cancer, vulvar and vaginal cancers are occurring more often in young women. "Management of the disease is extremely challenging," says Dr. Jorma Paavonen, lead study author. "Surgery is difficult and could be disfiguring."

Dr. Paavonen is chief physician in the department of obstetrics and gynecology at the University of Helsinki in Finland.

Vaccine May Prevent Multiple Cancers

"This study shows that the prophylactic vaccine developed to prevent cervical cancer could actually also prevent vulvar and vaginal cancer as well," says Dr. Paavonen.

"This could be a transforming vaccine for millions of women around the world," adds Dr. Robert F. Ozols, senior vice president of the Medical Science Division at Fox Chase Cancer Center in Philadelphia. "I don't think you can overestimate the benefit these vaccines will have," he says.

The Gardasil vaccine, made by Merck & Co., was developed to target four strains of HPV, two of which (HPV 16 and 18) are linked to cervical cancer and two (HPV 6 and 11) which cause anogenital warts.

Last month, an advisory panel of the US Food and Drug Administration (FDA) recommended that Gardasil be approved. This approval is expected on June 8.

Study Looked at Women Worldwide

The current study looked at combined data from three clinical trials evaluating Gardasil use by more than 18,000 women around the world.

The women, none of whom had been exposed to HPV at the start of the trial, were randomly assigned to receive at least one dose and up to three doses of the vaccine or a placebo over a six-month period and were followed for two years.

At the end of the trial, 24 women in the placebo arm and zero in the vaccine arm had developed high-grade pre-cancerous lesions associated with HPV 16 and 18. These lesions are precursors of vulvar and vaginal cancer.

"The vaccine efficacy was 100 percent against this disease caused by HPV types 16 and 18," Dr. Paavonen says.

Twenty-seven women in the placebo arm and five women in the vaccine arm developed lesions caused by all HPV types, giving the vaccine 81 percent efficacy against vulvar and vaginal cancers associated with any HPV type.

"These results suggest that this vaccine indeed may prevent vulvar and vaginal cancer," Paavonen said. "This represents additional health benefits that can be gained by the HPV vaccine."

Second HPV Vaccine Studied

Another research presentation at the ASCO meeting revealed Phase III results of a second HPV vaccine, this one made by GlaxoSmithKline.

All women in the study group demonstrated antibody response against HPV 16 and 18. The vaccine is very similar to Gardasil but does not target any HPV types other than 16 and 18, says Dr. Michael Bookman, director of medical gynecologic oncology at Fox Chase Cancer Center in Philadelphia.

Always consult your physician for more information.