At what age should Papanicolaou (Pap) smear screening commence?

From the Guidelines

Pap screening should begin at age 21 for women, regardless of sexual history, as recommended by the American Cancer Society guidelines 1. The screening should occur every 3 years until age 30. From ages 30-65, women can either continue Pap tests every 3 years or have a combination of Pap test and HPV testing (co-testing) every 5 years. After age 65, screening can be discontinued if there's a history of adequate negative prior screening and no history of significant cervical precancer. This recommendation is based on the natural history of HPV infection and cervical cancer development, as outlined in the guidelines 1. Most HPV infections in young women clear spontaneously without causing cancer, making screening before age 21 more likely to detect temporary changes that would resolve on their own. The gradual progression from HPV infection to cervical cancer typically takes 10-20 years, allowing time for screening to detect precancerous changes before they become invasive. Women who have had a total hysterectomy (removal of the cervix) for non-cancerous reasons generally don't need Pap tests, but those with a history of cervical precancer or cancer may need continued screening, as noted in the guidelines 1.

Some key points to consider:

• Women younger than 21 years should not be screened regardless of their age of sexual initiation 1.
• Women at any age should not be screened annually by any screening method 1.
• The preferred approach for women ages 30 to 65 years is to be screened every 5 years with the combination of HPV testing and cytology (“cotesting”) 1.
• Women should discontinue screening after age 65 years if they have had 3 consecutive negative cytology tests or 2 consecutive negative cotest results within the 10-year period prior to ceasing screening, with the most recent test occurring within the last 5 years 1.

Overall, the guidelines provide a clear framework for Pap screening, and the recommendation to start screening at age 21 is based on the most recent and highest quality evidence 1.

From the Research

Age to Start Pap Screening

The American Cancer Society guidelines suggest that screening for cervical cancer should start at the age of 25 years with Pap and/or human papillomavirus (HPV) testing 2. However, some studies suggest that targeted screening of younger women at risk for developing cervical intraepithelial neoplasia (CIN 2) may be beneficial 2.

Screening Guidelines

• The current guidelines recommend that women with a history of adequate screening and not otherwise at high risk may discontinue cervical cancer screening after 65 years of age 3.
• Women between 21-65 years should have a Pap test every 3 years or a Pap-human papillomavirus (HPV) cotest at 5-year intervals for women age 30-65 years 4.
• Screening should not begin before age 21, as recommended by the 2012 consensus guidelines 5.

Risk Factors

• Younger women who reported live births, smoking, contraceptive use, and a higher number of sexual partners were significantly at higher risk of being diagnosed with CIN 2 2.
• Women with persistent HPV infection remained at high risk for grade 2 or 3 lesions or cancer after referral for colposcopy 6.

Screening Trends

• There has been a decline in Pap screening rates over time, including an unexpected decline in 21- to 29-year-old women 4.
• Pap-HPV cotesting has significantly increased among women age 30-65 years, from 10.0% in 2007 to 60.8% in 2016 4.
• The proportion of females under age 21 who received a Pap test has declined steadily, from an average of 8.3% in 2011 to <1% in 2017 5.