DNA Test Beats Pap Smear in Cervical Cancer Detection, Study Finds

Oct. 17, 2007— -- Miranda Curlutu remembers the first time she went to the doctor's office for a Pap smear.

"The first time I went, I cried," says Curlutu. "I was so nervous, and the doctor wasn't very comforting about the situation. I actually brought my mom, but … I still cried."

Cervical cancer screening through Pap smears conducted for years during annual pelvic exams have been the standard screening approach for detecting early phases of the disease.

For some women, however, the annual exam may one day become a thing of the past. DNA tests for the cancer-causing human papillomavirus, which are more likely to detect early forms of cancer, could eventually mean less-frequent visits to the doctor for pelvic exams.

But there's a catch. Since these tests are so sensitive, a small number of women may end up getting false positive results, leading to extra tests and unnecessary alarm.

Studies on these new tests were published Wednesday in the New England Journal of Medicine.

The studies -- one Canadian and one Swedish -- found that HPV testing had almost twice the sensitivity of traditional testing, picking up more precancerous lesions than Pap smears do.

And since these tests are so sensitive, the authors speculated that women with negative tests may be able to safely go longer between pelvic exams for cervical cancer screening.

The DNA-based tests for HPV are performed with a pelvic exam, similar to the kind associated with traditional Pap smears.

But instead of the traditional approach of looking for cells showing early signs of cancer, the samples are sent for DNA tests that look for the presence of the human papillomavirus, a sexually transmitted virus that is the cause of most cervical cancers.

In the Canadian study, researchers assigned more than 10,000 women between 30 and 69 years of age to receive either DNA testing for HPV or traditional pap smears. HPV testing was found to be superior for picking up high-grade precancerous lesions, detecting 95 percent of these precursors to cancer, compared with 55 percent for traditional Pap smears.