Cervical cancer screening: Does HPV testing beat the Pap smear?

Q: I recently heard that the HPV test is better at screening for cervical cancer than the traditional Pap smear. Is this true? Does this mean that the HPV test will replace the Pap smear?

Sascha / Connecticut

Early findings from a large Canadian study suggest that the human papillomavirus (HPV) test is a far more accurate screening tool for cervical cancer than is the standard Pap smear. But the Pap smear isn't going away anytime soon.

Like a Pap smear, an HPV test is done on a sample of cells collected from your cervix. The difference is that a Pap smear checks only for changes in the cells of your cervix, while an HPV test checks for the genetic material (DNA) of human papillomavirus. It's an important difference, because several strains of HPV can lead to cervical cancer over time.

Canadian researchers reported that the HPV DNA test was nearly 40 percent better at detecting precancerous cervical lesions than was the Pap smear. The HPV DNA test did incorrectly identify normal cervical cells as precancerous more often than Pap testing did, but the difference was not as great as some previous studies had suggested. The findings are published in the Oct. 18, 2007, issue of the New England Journal of Medicine.

At this time, the HPV test remains a second-line evaluation for cervical cancer, ordered after a suspicious Pap smear result. It's also considered a useful addition to Pap testing for women older than age 30 who may be at high risk of cervical cancer. It's not used to screen women younger than age 30 with normal Pap results. This is because most HPV infections in women younger than age 30 clear up on their own and aren't associated with cervical cancer.