Hawaii women star in cancer-shot trials
Volunteers help test a vaccine aimed at protecting patients from cervical cancer
Hawaii played a big part in clinical trials of a vaccine to protect women from cervical cancer the past five years, according to a Honolulu investigator.
Evidence showed women who got the vaccine were protected from a sexually transmitted human papillomavirus infection, said Dr. Michael Carney, University of Hawaii John A. Burns School of Medicine gynecologist-oncologist.
"Scientifically, we can't make that big leap to cancer, but it's a pretty good marker that it probably will reduce the rate of cancer."
Dozens of isle volunteers participated in tests of Gardasil vaccine, which targets two subtypes of HPV that cause most cervical cancer, said Carney, head of the Women's Cancer Center at Kapiolani Medical Center for Women & Children.
It is also effective against two types of HPV virus that cause most genital warts, he said.
Volunteers ages 16 to 26 who met certain criteria were divided into two groups for the blind studies, he said. One group received the vaccine in a series of three injections over six months; the other received a placebo in the shots.
It will not be known for more than 10 years whether the shots prevented cervical cancer, because it takes that long for it to develop, Carney said. But he and co-investigators Lori Kamemoto and Santosh Sharma, obstetrics/gynecology professors, saw indirect results, he said.
Those who received the vaccine "pretty uniformly did not get infection," he said. "The other group did get infection at a rate consistent with the population."
Merck & Co., maker of the vaccine, sponsored the studies. "At least our population had an opportunity to participate, and, because it looks like it's hopefully going to be extremely helpful in preventing cervical cancer, our people were first in line to be part of it if they wanted to," Carney said.
The doctors still are following the participants, he said.
HPV infection is easily transmitted with one sexual contact, Carney said, explaining that more than 75 percent to 80 percent of women have an HPV infection at some time in their life.
In most cases it does not lead to cervical cancer, which raises the question of why some women get it and others do not, he said.
He said there are more than 75 subtypes of human papillomavirus, and probably a dozen have been linked to cervical cancer.
The vaccine is aimed at preventing the two viruses most commonly linked to cervical cancer. "We have other subtypes we have not done a vaccine for, so it leaves kind of a hole to protect people from," Carney said.
There is some thought that other HPV types have low numbers because of the two dominant ones, he said, "and if we take them out of the system, those other subtypes that cause cancer may roar into that gap."
Because of that, there still is a risk for cervical cancer, and women should not stop getting regular checkups, he stressed.
The Pap smear is "an amazingly good screening test that has virtually eliminated the risk of cervical cancer," Carney pointed out.
In 1940, he said, cervical cancer was the No. 1 cause of death for American women. Now it is about the 14th or 15th cause, with about 3,900 deaths every year, he said.
Most women dying of cervical cancer in the United States are not getting regular Pap smears, he said. "For women getting regular Pap smears, we are protecting them from deadly cervical cancer or catching it early."
It is unlikely that women who are not getting Pap smears can be reached to take the vaccine, Carney said. Price also is a hurdle, he said, saying three shots cost more than $300 and that insurance plans are not covering it or pay only a portion of it.
The Hawaii Medical Service Association covers the vaccine as part of the medical benefit, a spokesman said. The cost per shot is about $135-$140, and members pay about 20 percent of that, depending on their plan.
Kaiser Permanente's out-of-pocket cost for members for the three-shot series is $147, a spokeswoman said.
The vaccine was approved for females 9 to 26 years old, and the federal Advisory Committee on Immunization Practices recommends giving it to all 11- and 12-year-old girls.
Children were not tested in the trials, but the only way to make an impact on the cervical cancer rate is to give the vaccine to children, Carney said, "because vaccination rates for young children are extremely good, regardless of socioeconomic class."
Unless the vaccine is "delivered to the right people at no cost," he said, "I'm concerned that we will spend billions and billions on this vaccine and it still won't reduce 3,900 people dying every year."