Rationale for Screening Recommendations
Impact of Screening on Cancer Incidence and Mortality1 2 3 4
The Pap test is an effective and cost-effective cancer screening method. Since its introduction in the U.S. in the 1950s, cervical cancer deaths in the U.S. have decreased 74%. Most cases of invasive cancer are preventable with regular screening, follow-up, and treatment of abnormal results. About 50% to 64% of invasive cervical cancer cases are among women who have never been screened or have suboptimal screening (5 or more years since the last screening test).
Decreased incidence of cervical cancer and precancer will be best achieved by improving screening practices among those women who have never been screened or who are screened infrequently, and increasing HPV vaccination.
For women between the ages of 30 and 65 years, screening can be done with an HPV test alone (primary HPV testing), or with cytology (Pap testing) every 3 years, or with both HPV and Pap tests (co-test). Note that the U.S. Preventive Services Task Force states that primary HPV testing or Pap testing alone are preferred options. HPV testing is not recommended for women under 30 years of age, since most infections in this age group are transient.
HPV testing has—
- Higher sensitivity for diagnosis of high-grade squamous intraepithelial lesions (HSIL), squamous cell carcinoma, and adenocarcinomas.
- Lower specificity than Pap testing alone.
- More false positives compared to Pap testing.
Cervical cancer screening recommendations are the same for women who have received an HPV vaccine and women who have not received an HPV vaccine.5
HPV testing should be performed only to detect the presence of high-risk HPV. There is no role for testing for low-risk types, and tests for low-risk HPV should not be performed.
HPV testing identifies current HPV infections only, not past infections. It cannot distinguish among women never infected, women with a prior infection that has been cleared, and women with infections that generate too few HPV copies to meet the test’s detection threshold.
HPV Test Result Outcomes
A single HPV-positive test result in women 30 years of age or older provides a marker of increased risk for cervical cancer development. However, the positive predictive value of a single test is around 20% for precancer and even less for cancer.
For HPV-negative test results—
- If the woman was screened only with an HPV test, she may not need to be screened again for about 5 years.
- If the woman received a co-test and her Pap test result was negative, she may not need to be screened again for about 3 to 6 years.
Note: A woman who is screened only with a Pap test and receives a negative test result can wait 3 years to be screened again.
Continued Screening Is Still Needed After HPV Vaccination
Cervical cancer cytology screening recommendations remain unchanged for women who have been vaccinated for HPV because 10% of cervical cancer is caused by HPV types not included in the 9-valent vaccine, records of the number of vaccine doses may not be available, and sexually active women could have been infected prior to vaccination.
1Bos AB, Rebolj M, Habbema JD, van Ballegooijen M. Nonattendance is still the main limitation for the effectiveness of screening for cervical cancer in the Netherlands.external icon International Journal of Cancer 2006;119(10):2372–2375.
2Holcomb K, Runowicz CD. Cervical cancer screening.external icon Surgical Oncology Clinics of North America 2005;14(4):777–797.
3Janerich DT, Hadjimichael O, Schwartz PE, Lowell DM, Meigs JW, Merino MJ, Flannery JT, Polednak AP. The screening histories of women with invasive cervical cancer, Connecticut.external icon American Journal of Public Health 1995;85(6):791–794.
4Centers for Disease Control and Prevention (CDC). Cancer screening—United States, 2010. MMWR 2012;61(3):41–45.
5Centers for Disease Control and Prevention. Epidemiology and Prevention of Vaccine-Preventable Diseases. Chapter 11: Human Papillomavirus.pdf icon[PDF-271KB] Hamborsky J, Kroger A, Wolfe S, eds. 13th ed. Washington D.C. Public Health Foundation, 2015.