Cervical Cancer Screening

Donate today and support our programs

Support for the HPV Toolkit is provided by Merck Sharp & Dohme Corp., a subsidiary of Merck and Co., Inc.

Widely available Pap testing in the United States has led to tremendous reductions in the incidence and mortality of cervical cancer. Once the leading cause of cancer death among women in the United States, annual mortality per 100,000 women decreased from 5.55 in 1975 to 2.42 in 2007.6 In the same interval, incidence dropped from 14.79 cases per 100,000 women to 6.58.7

HPV Tests

A significant change to cervical cancer screening technology occurred in the 1990s with licensure of the first HPV DNA test to detect oncogenic types of the virus in clinical settings. Testing for high-risk HPV is useful as a tool to triage patients who are at greater risk for cervical precancers/cancer and are likely to benefit from colposcopy.8 Several such tests are now on the market in the United States and, in conjunction with cervical cytology, are approved for use in specific screening situations:

  1. As a follow-up test if the Pap result is unclear or borderline abnormal, as when atypical squamous cells of undetermined significance (ASC-US) are observed.8

  2. As a routine cervical cancer screening test in combination with a Pap test in women at or over 30 years of age (rather than just having the Pap test alone). Most anogenital HPV infections are acquired from the teen years through age 26; most infections resolve spontaneously, and most cancers result from long-persisting high-risk HPV infection.9,10 Therefore, HPV infections in women over 30 years of age are more likely to be both persistent and associated with prema¬lignant neoplasia or cancer, whereas most infections in younger women are transient and less likely to progress.11Thus, the combination test (Pap test plus HPV testing) can increase the effectiveness of detecting any problems early on, especially in women ≥30 years of age.8

Additionally, HPV16/18 genotyping tests have been available since 2009. These tests check directly for HPV types 16 and 18, which together are responsible for approximately 70% of cervical cancers.12 The potential advantage to genotyping may be to allow women who are high-risk HPV-positive, but negative for the more aggressive HPV16/18 types, to avoid immediate referral to colposcopy in favor of repeating Pap and HPV tests in 12 months.13

Cervical Cancer Screening Guidelines

In 2012 updated cervical cancer screening guidelines were issued by the both the USPSTF and the Cervical Cancer Guideline Committee of the ACS-ASCCP-ASCP. The two sets of guidelines were developed separately but are in agreement in most respects. Major changes include delaying the onset of cervical cancer screening to age 21 regardless of sexual history and lengthening of screening intervals to 3-5 years. A summary of both guidelines is below14,15:

  • Cervical cancer screening should begin at age 21
    • Most HPV infections acquired in teens and young adults clear up spontaneously, including those caused by high-risk types.21 It is now recognized that screening young women soon after onset of sexual activity results in large numbers of HPV infections and Pap test abnormalities that can safely be ignored, but that historically have resulted in unnecessary treatment accompanied by preventable anxiety and stress.
  • For women ages 20-29, screening with cytology alone every three years
  • For women 30 and over:
    • Screening every five years with cytology/HPV testing  (ACS guidelines say “co-testing” is  the preferred approach), OR
    • Screening every three years with cytology alone
    • Some concern over length of intervals, especially five year. However, The superior sensitivity of cotesting in the detecting high-grade diseases also allows for significant extension of cervical cancer screening intervals in women 30 and older.14
    • Women 65 and over: Cervical cancer screening can end for most women at age 65, provided they have a history of adequate screening tests with normal results
    • Post-hysterectomy: Screening is not recommended for women of any age after removal of the cervix unless there is a history of significant cervical precancer (CIN2 or higher).

    Note: some women and health care provider alike have expressed concern over the extended screening intervals, which is not surprising given the traditional “annual Pap” mindset. Evidence shows that screening intervals can indeed be safely lengthened and doing so will likely result in reduced morbidity associated with over-screening (such as unnecessary referrals to colposcopy).16