Overview

Screening With the Papanicolaou (Pap) Test: Benefits
Screening With the Pap Test: Harms
Screening Women Without a Cervix

Note: Separate PDQ summaries on Cervical Cancer Prevention, Cervical Cancer Treatment, and Levels of Evidence for Cancer Screening and Prevention Studies are also available.

Based on solid evidence, regular screening of appropriate women for cervical cancer with the Pap test reduces mortality from cervical cancer. The benefits of screening women younger than 25 years are small because of low prevalence of lesions that will progress to invasive cancer. Screening is not beneficial in women older than 60 years if they have had a history of recent negative tests.[1,2]

Magnitude of Effect: Regular Pap screening decreases cervix cancer incidence and mortality by at least 80%.

Study Design: Population-based and cohort studies.

Internal Validity: Good.

Consistency: Good.

External Validity: Good.

Based on solid evidence, regular screening with the Pap test leads to additional diagnostic procedures (e.g., colposcopy) and treatment for low-grade squamous intraepithelial lesions (LSIL), with long-term consequences for fertility and pregnancy. These harms are greatest for younger women, who have a higher prevalence of LSIL, lesions that often regress without treatment. Harms are also increased in younger women because they have a higher rate of false-positive results.

Magnitude of Effect: Additional diagnostic procedures were performed in 50% of women undergoing regular Pap testing. Approximately 5% were treated for LSIL. The number with impaired fertility and pregnancy complications is unknown.

Study Design: Evidence obtained from cohort or case-control studies.

Internal Validity: Good.

Consistency: Good.

External Validity: Good.

Based on solid evidence, screening is not helpful in women who do not have a cervix as a result of a hysterectomy for a benign condition.

Magnitude of Effect: Among women without cervices, fewer than 1 per 1,000 had abnormal Pap test results.

Study Design: Evidence obtained from a single cohort study.

Internal Validity: Good.

Consistency: Good.

External Validity: Good.

References

1. Sasieni P, Castanon A, Cuzick J: Effectiveness of cervical screening with age: population based case-control study of prospectively recorded data. BMJ 339: b2968, 2009.  [PUBMED Abstract]
   
   
2. Sawaya GF, McConnell KJ, Kulasingam SL, et al.: Risk of cervical cancer associated with extending the interval between cervical-cancer screenings. N Engl J Med 349 (16): 1501-9, 2003.  [PUBMED Abstract]