October 19, 2007
Human papillomavirus tests are more accurate than Pap tests in the detection of cervical cancer and precancerous changes in the cervix, according to two studies published on Thursday in the New England Journal of Medicine, the Wall Street Journal reports (Tomsho, Wall Street Journal, 10/18).
For one of the studies, Canadian researchers led by Eduardo Franco of McGill University performed a DNA test that detects HPV and a Pap test on 10,154 women ages 30 to 69. The HPV test detected 95% of cases in which participants had precancerous changes in the cervix, compared with 55% for the Pap test, the study found (Emery, Reuters, 10/17). However, the HPV test had a false positive rate of 6%, compared with 3% for the Pap test, according to the study.
The researchers recommended a shift from the Pap test to the HPV test as the primary detection method for cervical cancer (Gellene, Los Angeles Times, 10/18). Franco said that the DNA test costs about $90, compared with $10 to $20 for the Pap test, although mass production of the DNA test could help reduce the cost.
For the second study, Swedish researchers led by Pontus Naucler of Lund University performed the tests on 12,527 women in their 30s (Reuters, 10/17). The researchers divided participants into two groups, one that received both tests and one that received only the Pap test, and tracked them for an average of four years.
At the start of the study, researchers detected 51% more cases of cervical cancer or precancerous changes in the cervix in the group that received both tests, but they detected about the same number of cases in both groups by the end of the study. The study did not determine whether the earlier detection with the HPV test increased life expectancy for participants (Los Angeles Times, 10/18).
FDA has approved only one HPV test, USA Today reports (Rubin, USA Today, 10/18). Digene's DNA Pap test -- which combines the traditional Pap test with a DNA test for 13 strains of HPV -- was approved by FDA in as a primary screening tool for cervical cancer for women ages 30 and older (Kaiser Daily Women's Health Policy Report, 6/5).
The Canadian study is available online. The Swedish study also is available online.
CBS' "Evening News" on Wednesday included a discussion with CBS medical correspondent John LaPook about the studies (Couric, "Evening News," CBS, 10/17). Video of the segment is available online.