Human papillomavirus (HPV) can cause cervical cancer, vaginal cancer, and vulvar cancer in women and penile cancer in men. HPV can also cause anal cancer, oropharyngeal cancers, and genital warts in both sexes.
The virus is suggested to be responsible for more than 90 percent of anal and cervical cancers, around 70 percent of vaginal and vulvar cancers, and more than 60 percent of penile cancers. Studies have also shown that about 70 percent of cancers of the oropharynx may be linked to HPV.
All children who are 11-12 years old are recommended to receive the three-dose series of the HPV vaccine to protect against HPV. However, data have shown that only 42 percent of girls and 28 percent of boys between 13-17 years had completed the HPV vaccine series.
Previous research by Teri L. Malo, Ph.D. - a postdoctoral research associate at the Lineberger Comprehensive Cancer Center and the Department of Health Behavior, of the Gillings School of Global Public Health at the University of North Carolina (UNC) at Chapel Hill - has indicated that physician's recommendations for the HPV vaccine is a key predictor of vaccine uptake.
They found that many physicians recommend HPV vaccine inconsistently, behind schedule, or without urgency, which could contribute to under-immunization among adolescents and uncertainty in parents. The team also found that the strength of HPV vaccine recommendations from physicians does not align with national guidelines.
In this research - published in the journal Cancer Epidemiology, Biomarkers & Prevention - Malo and colleagues aimed to evaluate whether the language used by physicians would influence parents' decisions about whether to vaccinate their child against HPV.
Alongside their observations, the team also assessed physicians' willingness to use particular language when communicating with parents about HPV and recommending the vaccine.
Parents most likely to support messages affirming vaccine effectiveness
Malo, with senior author Noel Brewer, Ph.D., professor of health behavior at UNC Gillings School of Global Public Health and member of UNC Lineberger Comprehensive Cancer Center, and team conducted national surveys of 777 primary care physicians and 1,504 parents of adolescents ages 11-17.
Researchers communicated six brief messages developed by the study team and nine longer messages developed by the Centers for Disease Control and Prevention (CDC) to parents and asked them whether any of these specific messages would persuade them to allow their child the HPV vaccine.
Additionally, the team read physicians the six brief messages only and asked them if they would consider using them to persuade parents to use the HPV vaccine for their children.
Study results indicated that parents were most likely to be influenced by messages that emphasized vaccine effectiveness. A total of 70 percent of parents supported messages of the effectiveness of the vaccine, 67 percent supported messages explaining cancers prevented by the vaccines, and 65 percent supported messages detailing vaccine safety.
At least half of the participating parents supported three of the brief messages and eight of the longer messages, with no significant differences in support across demographic groups.
Deemed as the most persuasive brief message of the study - with endorsement from 65 percent of parents and 69 percent of physicians - was the phrase: "I strongly believe in the importance of this cancer-preventing vaccine for [child's name]."
Physicians preferred to use messages that emphasized the vaccine's role in preventing cancer, accounting for 64 percent support.
Parent-provider communication may increase HPV vaccination rates
Some parents that said at the beginning of the survey that they did not intend to vaccinate their child against HPV changed their minds from at least one of the messages included in the study.
Among parents who initially said no to vaccination and who were motivated to vaccinate by the messages, the most influential messages were both those that stressed the parents' role in preventing their child from getting HPV-related cancers and messages that highlighted the parents' role in whether their child becomes infected with HPV.
Most parents who avoid the HPV vaccine do so out of lack of information, according to Malo. They believe either the vaccine is unsafe or not needed, and say that they do not receive a strong enough recommendation from their child's physician to feel that it is necessary.
"Each of these concerns can be addressed by talking with a provider, and so it's important to understand what drives parents' hesitation so that we can help improve provider communication to decrease hesitancy about HPV vaccine. This finding really highlights the important role that parent-provider communication can play in increasing HPV vaccination."
Teri L. Malo, Ph.D.
Limitations of the study include that it is based on self-reporting and does not account for clinical context, which could include nonverbal cues or message modifications.
Further research by the team may identify whether parents' support of the brief or longer messages resulted in higher rates of vaccination across the survey participants.
AACR news release, accessed 29 September 2016.
CDC, HPV-associated cancer statistics, accessed 29 September 2016.
CDC, HPV vaccines: Vaccinating your preteen or teen, accessed 29 September 2016.
CDC, What is HPV? accessed 29 September 2016.
Missing the target for routine human papillomavirus vaccination: Consistent and strong physician recommendations are lacking for 11 to 12-year-old males, Susan T. Vadaparampil et al., CEBP, doi: 10.1158/1055-9965.EPI-15-1294, published 13 September 2016, abstract.
Quality of physician communication about human papillomavirus vaccine: Findings from a national survey, Melissa B. Gikey et al., CEBP, doi: 10.1158/1055-9965.EPI-15-0326, published online November 2015, abstract.