At what age should Pap (Papanicolau) testing begin?

Cervical Cancer Screening Age Guidelines

Cervical cancer screening should begin at age 21 years, regardless of sexual history or age of sexual debut. 1

Rationale for Starting at Age 21

• Extremely low incidence of cervical cancer in women under 21 years

  • Approximately 0.1% of all cervical cancer cases occur in women younger than 21 years 2
  • Annual incidence of only 1-2 cases per 1,000 females aged 15-19 years 2

• Potential harms of early screening:

  • Unnecessary procedures for lesions that would likely regress on their own 1
  • Increased risk of premature births following excisional procedures for precursor lesions 2
  • Anxiety associated with positive tests 2

Evolution of Guidelines

The recommendation to begin screening at age 21 represents a significant change from earlier guidelines:

• Previous guidelines (pre-2009) recommended starting screening approximately 3 years after initiation of sexual intercourse or by age 21, whichever came first 2

• In 2009, ACOG updated their guidelines to recommend beginning screening at age 21 regardless of sexual history 2

• By 2012, consensus guidelines firmly established age 21 as the starting point, leading to a steady decline in screening among women under 21 from 8.3% in 2011 to <1% in 2017 3

Current Screening Schedule After Age 21

For women with average risk:

• Ages 21-29: Cervical cytology (Pap test) alone every 3 years 2, 1
• Ages 30-65: HPV and cytology co-testing every 5 years (preferred) OR cytology alone every 3 years (acceptable) 2, 1

Special Considerations

• Women with special risk factors require different protocols:
  • HIV-infected women: Pap test twice in first year after HIV diagnosis, then annually if results are normal 1
  • Immunocompromised women
  • Women with in utero DES exposure
  • Women with previous cervical cancer or high-grade precancerous lesions

Implementation Challenges

Despite clear guidelines:

• Studies show many women continue to receive annual testing despite recommendations for longer intervals 4, 5
• As of 2010,73.1% of young women reported having a Pap test within the previous 12 months 6
• Implementation of the 2009 ACOG guidelines was gradual, with Pap testing among women under 21 dropping from 77% in 2008-2009 to 57% by December 2010 7

Key Takeaways

1. Begin cervical cancer screening at age 21 regardless of sexual history
2. No screening is recommended before age 21, even for sexually active individuals
3. Follow age-appropriate screening intervals (every 3 years for ages 21-29)
4. Special risk groups may require more frequent or earlier screening
5. Patient education is essential to explain the scientific rationale for beginning at age 21

The evidence clearly supports beginning cervical cancer screening at age 21, as the potential harms of earlier screening outweigh the benefits given the extremely low incidence of cervical cancer in younger women.