HPV Test Outperforms Pap Test for Detecting Cervical Abnormalities
In addition, conducting cervical cancer screening every three years (rather than every year) appears to be safe for women with normal results on both tests. These results will be presented at the 2011 annual meeting of the American Society of Clinical Oncology.
Each year in the United States, there are more than 12,000 new cases of cervical cancer and more than 4,000 deaths from the disease. Most cases of cervical cancer are caused by persistent infection with a high-risk type of HPV. The types of HPV that are linked with cervical cancer are transmitted sexually, and are extremely common. Most HPV infections clear on their own, but some persist and increase cancer risk.
For women age 30 or older, HPV tests are commonly used in combination with Pap tests for cervical cancer screening. The combination of HPV testing and Pap testing is not routinely used in younger women because many young women will have HPV infections that will clear on their own without causing cervical abnormalities. HPV testing may also be used for the further evaluation of an indeterminate Pap test result. This use of HPV testing is appropriate for women of all ages.
To assess how well HPV tests and Pap tests detect cervical abnormalities, researchers evaluated information from more than 330,000 women age 30 and older.
- The five-year risk of cervical cancer or precancer (CIN3+) was very low for women who had both a normal Pap test and a negative HPV test: 3.2 per 100,000 women per year.
- Considering each test individually, a normal Pap test was not as useful as a negative HPV test in identifying low-risk women. The rate of cervical cancer or precancer was 3.8 per 100,000 women per year among those with a negative HPV test, but 7.5 per 100,000 women per year among those with a normal Pap test.
- The HPV test was also better than the Pap test at identifying high-risk women. Women who tested positive for HPV had a higher risk of cervical cancer or precancer than women with an abnormal Pap test result.
- One important role for the Pap test may be further evaluation of women with a positive HPV test. Among women with a positive HPV test, the risk of cervical cancer or precancer was highest among those who also had an abnormal Pap test result.
In a prepared statement, the lead author of the study concluded “Our results are a formal confirmation that the three-year follow-up is appropriate and safe for women who have a negative HPV test and normal Pap result. These results also suggest that an HPV-negative test result alone could be enough to give a high level of security for extending the testing interval to every three years, but we’ll need additional evidence from routine clinical practice, and formal recommendations from guideline panels before that can be routinely recommended.”
Women are advised to talk with their healthcare provider about the cervical cancer screening strategy that’s right for them.
Reference: Katki HA, Kinney WK, Fetterman B et al. Cervical cancer risk for 330,000 women undergoing concurrent HPV testing and cervical cytology in routine clinical practice. Paper presented at: 2011 Annual Meeting of the American Society of Clinical Oncology; June 3-7, 2011; Chicago, IL. Abstract 1508.