What is the recommended follow-up for a 37-year-old woman with an Atypical Squamous Cells of Undetermined Significance (ASCUS) Pap test result and no Human Papillomavirus (HPV) detected?

Management of ASCUS Pap with Negative HPV in a 37-Year-Old Woman

For a 37-year-old woman with Atypical Squamous Cells of Undetermined Significance (ASCUS) Pap test result and negative HPV testing, the recommended follow-up is repeat Pap testing in 12 months. 1

Risk Assessment

• Women with HPV-negative ASCUS results have a low risk of precancer or cancer, but this risk is higher than after a completely negative cotest (HPV-negative/cytology-negative) 1
• The 5-year risk of cervical intraepithelial neoplasia grade 3 or higher (CIN3+) after an HPV-negative/ASCUS result is approximately 0.48%, which is closer to the risk after a negative Pap test alone (0.31%) than after a negative cotest (0.11%) 2
• The 5-year cancer risk after HPV-negative/ASCUS is 0.043%, compared to 0.031% after a negative Pap test and 0.014% after a negative cotest 2

Management Algorithm

1. Initial Management:

   • Repeat Pap testing in 12 months for a patient with ASCUS Pap result and negative HPV testing 1
   • Do not perform immediate colposcopy as it is unnecessary for HPV-negative ASCUS and can lead to overtreatment 1

2. Follow-up Management:

   • If the repeat Pap test is normal, return to routine screening 1
   • If repeat Pap tests show ASC or more serious condition, follow management according to the specific abnormality found 1
   • Continue repeat testing at 6- and 12-month intervals until two consecutive negative results are obtained, if abnormalities persist 1

Evidence Supporting This Recommendation

• The American Cancer Society recommends that women with an HPV-negative ASCUS result should return for screening in 3 years (not 5 years), consistent with the American Society for Colposcopy and Cervical Pathology (ASCCP) recommendation 3
• This recommendation is based on expanded data from Kaiser Permanente Northern California including 1.1 million women with extended follow-up, supporting a 3-year rather than 5-year interval 3, 1
• The principle of "similar management of similar risks" supports this approach, as the risk profile of HPV-negative ASCUS is closer to that of a negative Pap test alone 1, 2

Important Considerations

• High-grade histological changes after colposcopic evaluation for ASCUS Pap test reports are typically detected in less than 12% of cases 1
• Adding HPV testing in secondary screening increases the identification of women with CIN2-3 lesions by 33% compared with repeat cytology alone 4
• The prevalence of high-risk HPV infection in women with ASCUS decreases with age - at 37 years old, this patient falls in an intermediate risk category 4

Common Pitfalls to Avoid

• Avoid returning to screening too soon (before 12 months) as it is unnecessary and may lead to overtreatment 1
• Avoid waiting too long (5 years) between screenings after HPV-negative ASCUS as the risk is higher than after a completely negative cotest 1, 2
• Avoid performing colposcopy immediately for all ASCUS results regardless of HPV status as it can lead to unnecessary procedures 1
• Avoid assuming that an HPV-negative ASCUS result carries the same ultralow risk as a negative cotest 1

Clinical Practice Patterns

• Despite guidelines, many primary care physicians recommend more frequent screening than necessary - in one study, only 19% of physicians would follow the guideline-consistent 3-year interval for a 35-year-old woman with a normal Pap test result and negative HPV test 5
• The clinical significance of the ASCUS diagnosis varies with age, with younger women having higher rates of HPV positivity but often transient infections 4