Vaccinating boys against the human papillomavirus (HPV) might be cost effective over their lifetimes to prevent a type of throat and mouth cancer, new Canadian modelling suggests.
Dr. Lillian Siu, a senior medical oncologist at the Princess Margaret Cancer Centre in Toronto, has treated oropharyngeal cancer that starts at the back of the throat and mouth for about 18 years, and has seen the incidence of the disease rise.
The HPV vaccine is covered by provincial medicare plans for girls to prevent cervical cancer. The vaccine also reduces anal cancer in both genders as well as some cancers of the penis and oropharyngeal cancer, which also involves the tonsils and base of the tongue.
"We would see now about 80 per cent of our oropharyngeal cancer patients are what we call HPV positive," said Siu. "It is a morbid disease so I think we have to spend some time thinking about how to prevent it."
- HPV vaccine: Why boys are less likely to get it
- Revised HPV vaccine guidelines could boost immunization, Calgary expert says
- Peter Kent beats throat cancer, urges HPV vaccination for boys
- HPV vaccination concerns about promiscuity deemed 'unwarranted'
To that end, Siu and her team created a model to compare the potential cost savings of vaccinating a theoretical group of about 190,000 boys at age 12 followed over their lifetime using factors such as vaccine cost, vaccine effectiveness, costs of cancer treatment and how the quality of life of cancer patients diminishes.
"We don't know how to predict who will get the disease and anyone who is sexually active is at risk of developing such a cancer," Siu said.
In Monday's online issue of the journal Cancer, Siu and her coauthors concluded the vaccine could potentially save between $8 million and $28 million over the boys' lifetimes, or up to nearly $42 per person per year, compared with no vaccine.
Confrontation with mortality
Siu isn't advocating for the vaccine to be offered free to boys until more research is done. "I think if we can raise the awareness to start looking at this question in greater depth, we've achieved our goal."
One limitation of the model is the researchers weren't able to account for the interaction with smoking, another risk factor for oropharyngeal cancer. In developed countries, HPV is surpassing smoking as a cause factor, she said.
Conservative MP Peter Kent became an advocate for HPV vaccination after his diagnosis in 2013.
"It was my first confrontation with mortality and I thought, well, here we go," Kent recalled. "The diagnosis was Stage 4 HPV-related cancer, which is a fairly ominous diagnosis."
Kent had seven weeks of radiation treatment and three rounds of chemotherapy.
"I don't want any youngster today to face what I did, to experience what I did, 10 or 20 or 30 or 40 years down the road because it is avoidable and I think that governments have to face their responsibility and make that investment in the future."
Three doses of the vaccine cost about $500. B.C. and Quebec use two doses for girls. Currently, Alberta and Prince Edward Island cover the cost for boys. Nova Scotia's new budget includes plans to add HPV vaccines for boys in Grade 7 in the fall.
Toronto pediatrician Dr. Marvin Gans tells families about the costs and benefits of HPV vaccination for both girls and boys.
Some studies point to benefits for men by vaccinating women through herd immunity. "Clearly, the more girls that get [vaccinated] the decrease we'll see in males. However, that's not a guarantee of how to do things."
At Gans' office, Fern Stark sees the preventive value. "I think boys, teenaged boys, should have the vaccine. In fact my older son who is almost 17, has had it and I'm going to be making arrangements for my younger son, who is 13, to get it."