Battling Cervical Cancer: DNA Test More Effective Than Pap Smear

April 7, 2009— -- A DNA test that detects the human papillomavirus, which causes cervical cancer, is more effective than Pap smears at detecting and preventing the disease, according to a new study published in the New England Journal of Medicine.

"Good Morning America" medical contributor Dr. Marie Savard explains the difference between the two procedures and what it means for health.

How is this DNA test different from a Pap smear? And why is it more effective?

Pap smears check for cell changes caused by the cancer, but it is not foolproof. That's why it's done every year because it can miss some cell changes, which it might pick up the next year.

There are many reports of Pap smears not detecting abnormal cells until it's too late and the cancer is advanced. The DNA test, on the other hand, tests for the actual virus, which makes it much more effective as a test for cervical cancer because we now know that all cervical cancer is caused by this virus.

So if you test positive for the virus, the cancer can be detected and treated much sooner, without waiting for changes to the cells.

What should women do during their next doctor visit? Which test should they ask for?

Women should ask their gynecologist for the DNA test, in addition to the Pap test. The DNA test is not a blood test or even a separate test. The testing is done with the same swab sample used for the Pap test.

If both tests come back negative, you can have 100 percent peace of mind that you are not at risk for cervical cancer at least, in the near future. And under current guidelines, you don't need either test for three years. Because of this study, I think more and more doctors will now be giving both of these tests now.

Is this the end of Pap smears?

For a long time, Pap smears have been the gold standard when testing for cervical cancer. The good news is we now have smarter, better tests that work with the Pap smears and can find this cancer long before there are cell changes.

The DNA test for HPV is only used for women 30 and over. Many women get this virus but 90 percent of the time, their bodies get rid of the virus on their own and it does not lead to cancer.

So younger women often have the virus but their bodies simply have not gotten rid of it yet. There is only a risk of cancer if your body cannot get rid of the virus on its own. So it's only women 30 and over who still have the virus who are at risk for cervical cancer.