Showing posts with label cervical cancer. Show all posts
Showing posts with label cervical cancer. Show all posts

Friday, June 26, 2015

Study finds that one dose of HPV vaccine that targets only cervical cancer is as effective as three doses, now recommended

By Melissa Patrick
Kentucky Health News

A study has found that one dose of the human papillomavirus vaccine Cervarix appears to be as effective in preventing HPV infections that lead to cervical cancer as do three doses, the recommended course of vaccination. Only 25 percent of Kentucky adolescent women initiate the vaccination, and fewer than one in nine of those who do get three does, according to the Kentucky Cancer Consortium.

"Many women around the world and in the U.S. don't get the full three doses that are recommended, so this is promising news," said Elisia Cohen, an associate professor of communication at the University of Kentucky, who does extensive research on community strategies to improve adolescent and adult vaccinations. However, she cautioned that the drug Cervarix is "only 1 percent of the U.S. market" and that the findings from this study do not apply to Gardasil, the drug most commonly used in the U.S.

Dr. Diane Harper of the University of Louisville, one of the researchers, said in a news release, “Kentucky is one of the states that has not had a program in place to make Cervarix available to all of its citizens, and has very low three-dose completion rates of Gardasil.”

Most health departments and physicians choose Gardasil over Cervarix because it protects against four strains of HPV: two strains that cause 70 percent of all cervical cancers and two strains that cause genital warts and oral and anal cancers, concerns for males as well as females. Cervarix only protects against the two strains that cause cervical cancer. "Generally, the thinking is that protection against four strains is better that two," Cohen said.

She said Gardasil 9, which will protect against 90 percent of HPV strains that cause cervical cancer as well as pre-invasive cervical cancer lesions, has just been approved by the U.S. Food and Drug Administration and is going through its labeling process, and will be recommended for both boys and girls.

HPV is the most common sexually transmitted infection in the U.S., affecting an estimated 79 million individuals, according to the federal Centers for Disease Control and Prevention.

The study, published in The Lancet Oncology, analyzed data from two large trials of Cervarix. In the trials, women were randomly chosen to receive three doses of Cervarix or a control vaccine. All of the women were evaluated, regardless of how many doses of the vaccine they received, for the effectiveness of the vaccine for a period of four years. The analysis found that the protection from one dose was similar to that achieved by three doses of the vaccine.

“Knowing that Cervarix offers protection in one dose reassures public health agencies that they are not wasting money when most of their vaccines are given to those who never complete the three-dose series,” the researchers wrote.

The CDC recommends HPV vaccination for girls 11 and 12 years old, and catch-up vaccination for females from 13 to 26. The second dose should be given one to two months after the first injection; the third dose should be administered six months after the first dose.

Sunday, January 25, 2015

Appalachian women are more likely to get cervical cancer and die from it, but pass up vaccine partly because of fatalistic beliefs

By Melissa Patrick
Kentucky Health News

A fatalistic belief that getting or preventing cancer is beyond a person's control is one of many reasons young women in Appalachian Kentucky are likely to not get or complete the series of HPV vaccinations to prevent cervical cancer, according to a study by researchers at the University of Kentucky, published in The Journal of Rural Health.

"Our study found that fatalistic beliefs influenced immunization behaviors, which is concerning, given the high success rates of preventing HPV infection and cervical cancer through HPV vaccination and the elevated burden of cervical cancer in Appalachian Kentucky,” Robin Vanderpool, lead author of the study, said in an email.

The human papillomavirus, or HPV, is the most common sexually transmitted infection in the U.S., affecting an estimated 79 million individuals. Two types of HPV cause two-thirds of all cervical cancers, and unlike any other cancer, there is a three-dose HPV vaccine that can prevent it, according to the federal Centers for Disease Control and Prevention.

The UK researchers found that the women in the study who believed they had limited control over their health generally and limited control over cervical cancer specifically were significantly less likely to complete the HPV vaccine series than those who did not have this belief.

"This is an important finding because rural Appalachian residents often perceive cancer as pervasive, inevitable and mostly hereditary," the authors wrote.

The 344 rural Appalachian women who volunteered for the study were given the first dose of vaccine free of charge, and surveyed about their beliefs regarding cancer. They were followed for nine months after the first dose to determine completion rates.

Other studies had determined that many Appalachian women don't get or complete the HPV vaccine because of cost, lack of transportation, cultural views, lack of knowledge about cervical-cancer prevention and limited support from parents, peers and health-care providers. A belief in fatalism can now be added to this list.

Health advocates are working to get through these barriers because Appalachian Kentucky has the state's highest rates for cervical cancer and deaths from it, according to the Kentucky Cancer Registry. This, in a state that is among the top 14 for the most cases of HPV-related cervical cancers in the nation, according to the CDC.

Kentucky has a low HPV vaccination rate, with only one in four adolescent women initiating the vaccine and less than one in nine receiving the full series, according to The Kentucky Cancer Consortium. These rates are even lower in Appalachia, says the study.

The CDC recommends routine HPV vaccination for females ages 11-12 and catch-up vaccination for females ages 13-26. The second dose should be given one to two months after the first injection; the third dose should be administered six months after the first dose. Males are also encouraged to get the vaccine.

The study acknowledged that future such studies should compare women who have received the first dose of the vaccine, as in this study, against women who had not. It also suggests that these findings indicate a need for future research in how to educate and intervene with Appalachian women in a way that is culturally sensitive to improve HPV vaccination rates and to impact cancer disparities that affect the women in the region.