A vaccine that prevents cancer is the dream of just about every patient, doctor, and public health official. Therefore, hopes were quite high five years ago, when the U.S. Food and Drug Administration approved a vaccine to prevent human papillomavirus, or HPV, a sexually transmitted virus that causes almost all cases of cervical cancer.
But despite its clear efficacy, the vaccine has been something of a dud. According to a 2008 survey, only 34 percent of the target crowd, girls aged 13 to 17 years, had received it. The reasons for the slow uptake relate to generic vaccine issues (cost, pain, distrust) as well as a particular discomfort with this one, dubbed the "sex vaccine" by many conservatives, who object to it on the grounds that it somehow promotes licentious behavior (as if it were possible to make teenagers any hornier).
However, a new study presented at last week's annual meeting of the American Society of Clinical Oncologists makes the vaccine look even more valuable. Though preliminary and still unpublished, these findings have the potential to finally shift the perception that HPV is a woman's problem and convince parents to get their boys vaccinated against the virus, too.
The researchers make the most compelling case to date that HPV causes yet another malignancy—oropharyngeal cancer, a disease that affects men three times more often than women. (It's a subcategory of "oral" or "head and neck" cancer, which also predominantly affect men.) Their work appears to have settled a debate that had been rattling on for a decade, ever since clinicians first noticed a change in the way oral cancer was behaving.
In the past, oral cancer had been a disease of drinkers and smokers—the poster child was Ulysses S. Grant, who died of the disease (and knew plenty about drinking and smoking). But in the 1990s, more and more cases were seen in nonsmokers, puzzling clinicians; furthermore, the tumors were found in a different area of the mouth—the oropharynx (or front of the mouth), especially the tonsil and the base of the tongue. Previously, oral cancer tumors were mainly seen further back in the throat or near the voice-box.
So began a pursuit that proceeded along two lines of inquiry. First, the epidemiologists who track rates of cancer over time found an alarming rise in cancers of the tonsil and base of the tongue, with a simultaneous decrease in oral cancers found in the other, traditional smoking-related sites. Meanwhile, scientists found that many of the tumors in nonsmokers had HPV in them. Though an intriguing finding, this isn't the same as saying that HPV was causing the cancer. Perhaps HPV had been in oral cancers all along, and no one had thought to look.
So that's exactly what the current investigators did. The researchers, from the National Cancer Institute, examined 271 oropharynx tumor samples collected between 1984 and 2004 using new, super-sensitive molecular detection methods that were not available in the '80s and '90s. Bingo: They found a four-fold increase in HPV-positive tumors over the 20 years. (HPV was in 16 percent of early samples, compared to 73 percent of recent ones.)
In many people's view (including mine), this new study nails HPV as the cause of many oral cancers. At the same time, it makes a mighty persuasive case for boys to get vaccinated against HPV. This is a good thing: If vaccination rates are low for girls, they're invariably lower for boys, who until now had no logical (read: selfish) reason to get the expensive series of shots. (The FDA approved the vaccine for boys in 2009, but wimpily, without any strong recommendation to actually administer it.) OK, sure, it prevents venereal warts, which are no fun. But warts may not seem like such a big deal to a harried mom who has to drag her little darling to the pediatrician three times in six months to ward them off. Now that HPV has been convincingly linked to oral cancer in men, parents have a much more compelling reason to get Junior vaccinated than altruistic concerns about the health of any future female sex partners he may have.