Fred Hutch researcher reflects on the impact of major vaccine breakthrough against cancer
By Clay Holtzman, Hutchinson Center science writer
Significant breakthroughs in cancer research aren’t easy to come by. It is also rare that such discoveries turn out to have an even bigger impact than first heralded.
Dr. Denise Galloway is fortunate to be part of both.
Galloway was one of the key researchers behind the development of the vaccine for Human papillomaviruses (HPVs), the virus known to cause all forms of cervical cancer. Approved in 2005, the HPV vaccine is the world’s only cancer vaccine and a major breakthrough in the fight against cancer. Galloway, who studies the link between viruses and cancer, recently put the vaccine’s discovery into context.
“In just 25 years, we went from not having any idea what viruses were involved in these cancers to having a vaccine,” she said. “That’s amazingly fast.”
More than 11,000 women in the US were diagnosed with cervical cancer in 2011. But continued research has shown that HPV is linked to some forms of other cancers in both women and men, including anal, genital and oral. And Galloway’s lab is working with colleagues at Fred Hutch to identify other viruses that may be involved with cancer.
The story behind the HPV vaccine reminds me a little of the Center’s landmark research in developing bone marrow transplantation. That treatment was first used to treat leukemia patients, but over time it has been used as the basis to treat other forms of cancers. It is a research breakthrough that just keeps on giving.
When I met with Galloway recently to discuss revisions to federal guidelines for cervical cancer screening, I told her I thought it must be pretty “cool” to be involved with a discovery that could have as big an impact as actually preventing cancer from occurring.
“Yeah, it kind of is,” she said. I asked her a few other questions:
When the vaccine was first discovered, did you have a sense that one day it could prevent more than just cervical cancer?
At the time, we knew that other anogenital cancers—Vulvar, vaginal, penile and anal cancers—were also caused by HPV, though perhaps not as high a percentage as the 100 percent of cervical cancers (Researchers generally agree that a group of at least 12 HPVs infect the genital tract, causing lesions that can progress to cervical and other anogenital cancers).
We also knew that about 30 percent of cervical cancers were caused by HPV types not in the vaccine, so people would not be protected against them. The big surprise came with finding that oropharyngeal cancers (tonsils and base of tongue) were also caused by HPVs, primarily HPV 16.
What’s been your reaction to the expanding impact and value of the HPV vaccine?
It’s great that it is recommended for both girls and boys, as it will both protect men against HPV disease and increase the likelihood of protection in women.
What’s next for this life-saving vaccine?
There are two big challenges—one scientific and one societal. First the vaccine needs to be expanded to cover more HPV types.
Merck (the maker of the vaccine) is taking the approach of including more HPV VLPs from additional types, along with the existing HPVs 6, 11, 16 and 18. Another group is working to develop a vaccine from a different HPV protein, L2, that has a broadly cross-reactive epitope. We’ll see.
Secondly, the challenge is to get the HPV vaccine where it is needed. Cervical cancer remains a leading cause of death in the developing world, but getting vaccines to them is a challenge on many levels, not just financial.
But even in the US, the levels of uptake are disappointingly low, with only one-third of teenage girls getting all three shots. Lack of education about the importance of the vaccine, general resistance to vaccines and pharma and conservative social ideas all stand in the way of reducing HPV-associated disease as a cause of human suffering and death.