What is the next step for a 59-year-old patient with an Atypical Squamous Cells of Undetermined Significance (ASCUS) Pap smear result?

Management of ASCUS Pap Smear in a 59-Year-Old Woman

Perform HPV testing (reflex HPV testing for high-risk types) as the next step, followed by colposcopy if HPV-positive. 1, 2

Primary Management Algorithm

For a 59-year-old woman with ASCUS, the management pathway depends critically on HPV status:

If HPV Testing Available (Preferred Approach)

• HPV triage testing is the strongly recommended primary management strategy for women aged 30-65 years with ASCUS. 1
• HPV testing achieves 88-90% sensitivity for detecting high-grade lesions, significantly superior to repeat cytology alone (76.2% sensitivity). 1, 2
• The ASCUS-LSIL Triage Study (ALTS) demonstrated that HPV triage is at least as sensitive as immediate colposcopy for detecting CIN III while referring approximately half as many women to colposcopy. 1

If HPV-Positive for High-Risk Types

• Proceed immediately to colposcopy - this is non-negotiable for women over 30 years with HPV-positive ASCUS. 3, 1, 2
• HPV-positive ASCUS carries approximately 20% risk of CIN2+ and 9.7% risk of CIN3+ in this age group. 1, 2
• At age 59, HPV positivity is more concerning and less likely to represent transient infection, with higher risk of underlying significant disease compared to younger women. 3, 2
• HPV types 16 and 18 carry the highest risk (17% and 14% respectively for CIN 3+), compared to 3% for other high-risk types. 3, 2

If HPV-Negative

• Follow-up with co-testing (cytology and HPV) at 3 years - not 5 years as previously recommended. 1
• The risk of precancer is less than 0.15% over 5 years following a negative HPV test result. 4
• Even at age 59, HPV-negative ASCUS does not allow cessation of screening - continued surveillance is required until 2 consecutive negative co-tests or 3 consecutive negative Pap tests. 1

If HPV Testing Unavailable (Alternative Options)

• Repeat cytology at 12 months is acceptable but suboptimal. 1
• Immediate colposcopy is another option, though this leads to overtreatment in HPV-negative cases. 1
• Single repeat cytology at 6 and 12 months can be considered. 1

Colposcopy Protocol (When Indicated)

• If colposcopy is satisfactory and shows CIN 2+, proceed with appropriate treatment (ablation or excision). 3, 1, 2
• If colposcopy shows CIN1 or negative findings, repeat co-testing at 12 months. 1
• If colposcopy is unsatisfactory, perform endocervical curettage and cervical biopsy. 3, 1

Critical Pitfalls to Avoid

• Never delay colposcopy in HPV-positive ASCUS cases in women over 30 - this increases risk of missed high-grade disease. 3, 1, 2
• Do not rely on repeat cytology alone for HPV-positive ASCUS - sensitivity is only 76.2% compared to immediate colposcopy. 3, 2
• Avoid unnecessary colposcopy for ASCUS with negative high-risk HPV - this leads to overtreatment. 1, 2
• Do not perform HPV 16/18 genotyping for ASCUS triage - it does not alter management, as all women with ASCUS who are positive for any high-risk HPV should proceed to colposcopy. 1
• Do not assume this patient can discontinue screening - even if HPV-negative, she requires continued surveillance until meeting exit criteria (2 consecutive negative co-tests or 3 consecutive negative Pap tests). 1

Evidence Strength

The recommendation for HPV triage is based on strong consensus guidelines from the National Comprehensive Cancer Network, American College of Obstetricians and Gynecologists, and American Society for Colposcopy and Cervical Pathology, with high-quality evidence from the ASCUS-LSIL Triage Study. 1, 2 The colposcopy referral rate for ASCUS is approximately 23.2% at 12 months, with CIN 2/3 prevalence of 3.3%. 5