Here's an interesting potential side effect of the new HPV (human papillomavirus) vaccine (which, despite backlash from mostly Christian parent activist groups, is receiving very favorable reception, with 10 states considering requiring that all girls be vaccinated): The vaccine may render the Pap smear obsolete. On Tuesday, the New York Times reported that the recommended annual Pap test -- which screens for precancerous lesions and typically comes complete with a drafty gown and an icy speculum -- is likely to become less relevant as cervical cancer becomes less common.
Good news for everyone who's sick of stirrups? Maybe, maybe not. Since the HPV vaccine Gardasil doesn't protect against all the cancer-causing strains of HPV, screening mechanisms will still be necessary. And the new alternative to Pap smears, a genetic HPV test, has its own downsides: At $50 to over $100 per test, it's more expensive than the roughly $20 Pap smear, and while the genetic test generally seems to produce more accurate results than Pap tests do, it tests only for HPV, not for cancerous or precancerous cells. Since most sexually active women are likely to be infected with HPV at some point in their lives, and many of those infections clear up on their own, testing for HPV rather than precancerous cells might be overkill -- especially since women who tested positive for HPV would need to undergo additional testing for cervical lesions. (The genetic test also involves stirrups, though advocates believe a simpler, self-administered test eventually will become available.)
Of course, Pap smears have their own accuracy problems; there are plenty of cases of women having several years' worth of normal Pap results and still winding up with cervical cancer. And the vaccine is likely to further compromise the perceived value of Pap tests; the Times explained, "As more women get the HPV vaccine ... the number of lesions will decline, making the Pap test more costly per cancer case detected." The paper added that as technicians become less accustomed to seeing lesions, they "may lower their guard -- and their accuracy." Pap tests aren't very practical for or widely available in developing countries; a low-cost genetic test for HPV could make a huge difference in less affluent areas of the world, where cervical cancer is still a major killer of women.
Personally, I like the idea of the genetic HPV test; if I were to have a sexually transmitted disease that also put me at risk for cancer, I'd rather know about it. But, like many women, I'm reluctant to forgo the ritual of the annual Pap test; if nothing else, it ensures that I get at least a cursory once-over by a physician each year. So if, as the Times predicts, the routine testing fades in importance or use, I'll be sorry to see it go. As thorny as debates about healthcare costs and efficacy tend to be, though, that we're having this debate at all speaks to the likelihood that cervical cancer will become much less common -- and that's still fantastic news.
And speaking of fantastic news in cancer research, we wanted to call out a more general, and tentative, finding: Today, the New Scientist reports that the drug dichloroacetate (DCA), which is used to treat metabolic disorders, has been found to kill most cancers in early testing. The finding is preliminary and has yet to be tested in human cancer patients, and because DCA is not patented, pharmaceutical companies are unlikely to foot the bill for any such testing. (On the plus side, if DCA does prove to be good for treating cancer, it's likely to be very cheap.) Lastly, the Associated Press reports today that cancer deaths in the U.S. have dropped for the second year in a row -- from 2002 to 2003, the deaths attributed to cancer dropped by 369; from 2003 to 2004, they dropped by 3,014. "[American] Cancer Society officials attributed the decline to early detection and improved treatment," the AP reports.