Five-Year Risks of CIN 2+and CIN 3+Among Women With HPV-Positive and HPV-Negative LSIL Pap Results

Objective. Low-grade squamous intraepithelial lesion (LSIL) Pap results do not typically lead to human papillomavirus (HPV) testing. HPV triage is not cost-effective because most cases are HPV-positive. However, under new national guidelines recommending cotesting for women aged 30 to 64 years, clinicians will increasingly receive the HPV test result with LSIL Pap results. Some authors have suggested that HPV triage might be effective at older ages, when the percentage of HPV positivity among women with LSIL declines. Methods. We estimated 5-year risks of CIN 2+ and CIN 3+ among 9,033 women aged 30 to 64 years who had both an HPV test and an LSIL Pap result. Results. HPV positivity among women with LSIL decreased only slightly with age (30 to 34 vs 60 to 64 years, 88% vs 72%, p < .0001). The 5-year risks of CIN 2+ and CIN 3+ of women aged 30 to 64 years testing HPV-positive/LSIL were larger than those among women testing HPV-negative/LSIL (CIN 2+, 19% vs 5.1%, p < .0001; CIN 3+, 6.1% vs 2.0%, p < .0001). The 5-year risk of CIN 3+ in HPV-negative/LSIL women was similar to that for women with atypical squamous cells of undetermined significance (ASC-US) Pap test result without knowledge of HPV test results (2.0% vs 2.6%, p = .4). Conclusions. HPV-negative/LSIL posed lower risk than other Pap results that guidelines currently recommend for referral to immediate colposcopy. By the principle of "equal management of equal risks," women with HPV-negative/LSIL might reasonably be managed similarly to those with ASC-US Pap results without knowledge of HPV testing, that is, retesting at 6 to 12 months, rather than immediate colposcopy. Although the HPV test result for LSIL Pap results provides actionable information to clinicians who screen with cotesting, the high HPV positivity of LSIL at even the oldest ages suggests the lack of cost-effectiveness of HPV triage of LSIL for clinicians who do not use routine cotesting.