On a sunny day in 1998, Maura Gillison was walking across the campus of Johns Hopkins University in Baltimore, Maryland, thinking about a virus. The young oncologist bumped into the director of the university's cancer centre, who asked politely about her work. Gillison described her discovery of early evidence that human papillomavirus (HPV) — a ubiquitous pathogen that infects nearly every human at some point in their lives — could be causing tens of thousands of cases of throat cancer each year in the United States. The senior doctor stared down at Gillison, not saying a word. “That was the first clue that what I was doing was interesting to others and had potential significance,” recalls Gillison.
She knew that such a claim had a high burden of proof. HPV was known to cause cervical cancer and small numbers of genital cancers, but no other forms. So Gillison started a careful population study comparing people with cancer to healthy individuals. Over seven years, she recruited 300 participants, collected tissue samples, and never once looked at the data. “My policy, when doing a study, is that we wait until all the data are in, and do all the analyses at once,” says Gillison, who is as careful as she is blunt. “I don't know anything until the data tell me.”