Low-grade squamous intraepithelial lesion on Papanicolaou test: follow-up rates and stratification of risk for high-grade squamous intraepithelial lesion

Abstract

Introduction: Low-grade squamous intraepithelial lesion (LSIL) Papanicolaou test is associated with moderate risk of high-grade squamous intraepithelial lesion (HSIL) at colposcopic biopsy. High-risk human papillomavirus (hrHPV) cotesting risk stratifies patients with LSIL Papanicolaou test, with higher rates of HSIL for those hrHPV+. hrHPV genotyping is not considered in current LSIL management algorithms.

Materials and methods: We performed a 2-year retrospective review of LSIL Papanicolaou tests in patients 25 to 65 years old to assess rates of follow-up and HSIL at biopsy. Patient age, hrHPV cotest and genotype results, prior screening results, and follow-up testing for 3 years were recorded.

Results: A total of 71.5% (376 of 526) of patients had at least 1 follow-up colposcopic biopsy; 18% had HSIL on follow-up, including 20% of hrHPV+ and 12% of hrHPV-. HSIL at biopsy was most common when HPV16/18 was present (32%) and when multiple subtypes were detected (46%) versus when non-16, non-18 hrHPV alone was present (16%) or hrHPV was negative (12%). Of those hrHPV-, 5 of 22 (23%) with a prior screening abnormality had HSIL versus 1 of 27 (4%) for those without prior abnormalities. Follow-up occurred more commonly for hrHPV+ cotests (82%) than hrHPV- cotests (54%). No differences in follow-up rate based on hrHPV genotyping was seen.

Conclusions: The highest HSIL rates were seen when HPV16/18 was present (32%). HSIL rates were similar for those hrHPV- (12%) and non-16, non-18 hrHPV+ (16%). Follow-up was more common for those hrHPV+, but genotype results did not impact follow-up rates. Past screening results may impact risk of HSIL for hrHPV- cases.

Keywords: Cervical cancer screening; HSIL; Human papillomavirus; LSIL; Pap test.