Cervical cytology of atypical squamous cells, cannot exclude high-grade squamous intra-epithelial lesion: significance of age, human papillomavirus DNA detection and previous abnormal cytology on follow-up outcomes.

OBJECTIVE: Despite the usefulness of Pap tests for cancer screening, outcomes can be difficult to predict when atypical squamous cells (ASCs) are identified. According to the 2001 Bethesda system, ASCs can be subdivided into two groups: ASCs of undetermined significance (ASC-US); and ASCs, cannot exclude high-grade squamous intra-epithelial lesion (ASC-H). ASC-H interpretations are uncommon, and studies involving this type of lesion are based on small numbers of cases.

STUDY DESIGN: Cross-sectional, retrospective study of 392 ASC-H cases. The follow-up outcomes of ASC-H cases that were diagnosed during routine primary screening between 2002 and 2008 were investigated, and relationships between clinicopathological parameters were assessed, particularly positive test for high-risk HPV (HPV) DNA, patient age at diagnosis and previous abnormal cytology.

RESULTS: Of the 392 cases, high-grade squamous intra-epithelial lesion (HSIL) was detected in 111 (28.3%) cases, squamous cell carcinoma was detected in 15 (3.8%) cases, low-grade squamous intra-epithelial lesion was detected in 37 (9.4%) cases, reactive change was detected in 178 (45.4%) cases, atrophy was detected in 47 (12.0%) cases, and adenocarcinoma was detected in four (1.0%) cases. The prevalence of HSIL or greater was 27.8% for women aged ≥ 40 years, and 52.3% for women aged <40 years (p<0.001). HPV positivity in ASC-H smears was significantly associated with HSIL or greater, irrespective of age (<40 years, p=0.003; ≥ 40 years, p<0.001). ASC-H with previous abnormal cytology greater than ASC-US showed a significantly higher detection rate for HSIL or greater at follow-up (p<0.001).

CONCLUSIONS: Patient age, positive HPV DNA test and previous abnormal cytology are useful predictors of underlying HSIL or greater in women with ASC-H.