HPV Shots for Boys Might Cut Cancer Costs

Source: MedPageToday.com

Author: Charles Bankhead

– Canadian study suggests vaccination would save money by preventing oropharyngeal cancer.

Widespread vaccination of boys against human papillomavirus (HPV) infection proved to be a cost-saving approach to prevent subsequent head and neck cancer, according to data based on the Canadian health system.

A 70% immunization rate and 99% efficacy with the quadrivalent vaccine Gardasil might reduce costs by as much as $28 million ($22.2 million U.S.). Reducing uptake and efficacy to 50% still might save $8 million ($6.35 million U.S.), Lillian L. Siu, MD, of Princess Margaret Cancer Center in Toronto, and co-authors reported online in Cancer.

“According to the findings of this preliminary analysis, HPV vaccination for boys aged 12 years may be a cost-effective strategy in relation to the prevention of oropharyngeal cancer alone, strengthening the cost-effectiveness of a male vaccination program,” the authors concluded. “The argument for funding male HPV vaccination in North America is becoming more compelling given the benefits of reductions in genital warts and anal cancer and the potential benefits for the female population because of increased herd immunity.

“Prospective data collection for male HPV vaccination and oropharyngeal cancer may validate these findings in the future.”

The data are consistent with other studies showing cancer benefits for HPV immunization, although the Canadians are the first to suggest that vaccination saves money, U.S. sources told MedPage Today.

Background

Initial clinical studies of HPV vaccination and national vaccination programs targeted girls and young women. Only recently has the focus expanded to include immunization of adolescent boys. Moreover, proponents of HPV immunization increasingly have emphasized the potential cancer-prevention benefits of preventing HPV infection, which accounts for the majority of new cases of cervical cancer and head and neck cancer (primarily oropharyngeal) cancer, the latter being a male predominant-condition.

Although nations have begun to include boys in national immunization initiatives (including the U.S.), few studies have examined the cost-effectiveness of HPV vaccination from the perspective of disease (including cancer) prevention in boys and men. To address the issue, Liu and colleagues performed a preliminary cost-effectiveness analysis based on Canadian data.

On the basis of literature-derived data on HPV-related oropharyngeal cancer in Canadian men, investigators developed a Markov model to compare the costs and effectiveness of immunization with the quadrivalent HPV vaccine versus no immunization. The model was based on a theoretical cohort of 192,940 boys who were 12 years old in 2012.

Vaccination costs applied to use of the quadrivalent vaccine. Costs associated with oropharyngeal cancer were derived from records of patients treated at the Toronto center from 2000 to 2010 and from data on patients treated throughout Ontario during 1997 to 2007. The primary outcome was the incremental cost per quality-adjusted life year(QALY).

The model considered two principal scenarios: 70% vaccine uptake and 99% vaccine efficacy and 50% uptake and efficacy. In both scenarios, the comparator was no vaccination.

Key Findings

For the 70%/99% scenario, the model yielded a 0.05 QALY and a savings of $145 (~$115 U.S.) per individual as compared with no vaccination. For the 50%/50% scenario, the model showed a gain of 0.023 QALY and a savings of $42 (~$33 U.S.). Extrapolation of the results to the entire nation resulted in potential savings of $8 million to $28 million with the two vaccination scenarios.

Though limited to the Canadian perspective, the study suggests potentially large savings in the U.S. as well. The average cost of 1 year of care care for a patient with newly diagnosed oropharyngeal cancer is $25,697 in Canada, whereas the cost estimates for the U.S. range from $79,151 for patients with commercial insurance to $59,404 for Medicaid patients to $48,410 for patients covered by Medicare.

The authors’ model assumed a fixed cost of $400 (~$318 U.S.) for the vaccine, and they acknowledged that the cost of the vaccine has been a limiting factor in the uptake in developed nations. They also acknowledged that the model did not take into account recent increases in the proportion of oropharyngeal cancer attributable to HPV infection.

The status of immunization for boys has lagged behind that of girls throughout much of the world, primarily because of research priorities surrounding vaccine trials.

“The data for clinical trials in girls came out a couple of years ahead of the data for boys, so the vaccine wasn’t FDA approved or recommended by anyone for boys,” said Debbie Saslow, PhD, of the American Cancer Society in Atlanta, which supports immunization of boys and girls. “The manufacturer didn’t ask for an indication for boys. If you start out just vaccinating girls, then, of course, there is going to be a big lag in the data.”

U.S. Perspective

In the U.S., the situation is changing rapidly, and in some states, the HPV immunization rate for boys has increased dramatically and the gap between the sexes will likely close in the near future, she added. Worldwide, however, the U.S., Canada, and Australia are the only nations that currently support HPV immunization of boys and girls.

Speaking to the Canadian study results, Saslow said studies have consistently shown that HPV immunization is cost-effective for cancer prevention, but the cost-saving result is something new.

The Canadian study attempted to address one of the problems inherent in assessing the cancer-prevention potential of HPV immunization in women and men, said Rodney Willoughby, MD, of Children’s Hospital of Wisconsin in Milwaukee.

“This is essentially an anticancer vaccine,” said Willoughby, who also is a member of the American Academy of Pediatrics’ committee on infectious diseases. “The female cancers [associated with HPV] often have premalignant lesions, which allow you to do very nice, well-powered studies to show remarkable benefit in terms of preventing precancerous lesions in the real-world setting or, even more so, preventing the cancers themselves.

“The problem with the males is that they have a higher burden of the oropharyngeal cancers, and there is no precancerous marker that allows you to do studies in a short period of time.”

A lot of the information to support immunization of boys has come from extrapolation, he added. Impetus for the support has come from historically low uptake of the vaccine among girls and growing recognition that boys and girls have a similar risk of infection.

Although the Canadian and U.S. healthcare systems differ in many respects, the two governments regularly share and discuss healthcare data, so it’s reasonable to assume that the Canadian study is applicable to the U.S., said Willoughby.