HPV testing best at detecting early cervical cancer

NEW YORK (Reuters Health) - Testing for the presence of cancer-related human papillomavirus (HPV) is more sensitive than Pap testing in identifying cancer or pre-cancerous cells in the cervix that will probably progress to cancer if they are not removed.

HPV testing can detect this condition, also referred to as cervical intraepithelial neoplasia (CIN), and reduce the occurrence of cancer on subsequent screening exams, according to the findings of two clinical trials appearing in The New England Journal of Medicine.

In the first trial, Dr. Eduardo L. Franco, from McGill University in Montreal, and colleagues compared HPV testing and conventional Pap testing as a screening method for detecting high-grade CIN in 10,154 women.

HPV testing had a sensitivity of 94.6 percent for picking up advanced forms of CIN compared with a sensitivity of only 55.4 percent for Pap testing. Pap testing had a slightly but statistically significant higher specificity of 96.8 percent vs. 94.1 percent.

Using both tests together resulted in a sensitivity of 100 percent and a specificity of 92.5 percent, the report indicates. The use of Pap and HPV testing helped reduce the number of unnecessary referrals for surgical removal of cervical tissue, but the two tests together were not as sensitive, meaning that it may have miss some cases, compared with the use of either test alone.

In the second study, Dr. Joakim Dillner, from Malmo University Hospital in Sweden, and colleagues assessed CIN-related outcomes in 12,527 women who were randomly assigned undergo cervical cancer screening with Pap testing alone or in combination with HPV testing.

Fifty-one percent more women in the two-test group had advanced CIN or cancer than women in the Pap-only group. Moreover, the rate of high-grade CIN or cancer detected at subsequent screening examinations in the two-test group was reduced by 42 percent compared with the Pap test-only group, the team reports.

If more studies confirm these results, "there will be a need to develop a rapid, simple, accurate, and affordable HPV DNA test," Dr. Carolyn D. Runowicz, from the University of Connecticut Health Center in Farmington, notes in a related editorial.

SOURCE: The New England Journal of Medicine, October 18, 2007.