Background: Minor cervical cytologic abnormalities include atypical squamous cells of undeterminedsignificance (ASC-US) and low-grade squamous intraepithelial lesion (LSIL). Approximately 10-20% of womenwith minor cytologic abnormalities have histologic high-grade squamous intraepithelial or worse lesions (HSIL+).In Thailand, women with minor cytologic abnormalities have a relatively high risk of cervical cancer, and referralfor colposcopy has been suggested. A triage test is useful in the selection of women at risk for histologic HSIL+ toreduce the colposcopy burden. The aim of this study was to assess the performance of high-risk HPV DNA test intriage of women with minor cytologic abnormalities in northern Thailand. Materials and
Methods: All womenwith ASC-US/LSIL cytology who were referred to our colposcopy clinic from October 2010 to February 2014were included. HPV DNA testing was performed using Hybrid Capture 2 (HC2). All patients received colposcopicexamination. Accuracy values of HC2 in predicting the presence of histologic HSIL+ were calculated.
Results:There were 238 women in this study (121 ASC-US and 117 LSIL). The HC2 positivity rate was significantlyhigher in the LSIL group than in ASC-US group (74.8% versus 41.0%, p<0.001). Histologic HSIL+ was detectedin 9 women (7.4%) in the ASC-US group and 16 women (13.7%) in the LSIL group (p=0.141). There was nohistologic HSIL+ detected among HC2-negative cases (sensitivity and negative predictive value of 100%). Theperformance of HC2 triage was highest among women aged >50 years with ASC-US cytology. An increase in thecut-off threshold for positive HC2 resulted in a substantial decrease of sensitivity and negative predictive value.
Conclusions: HPV DNA testing with HC2 shows very high sensitivity and negative predictive value in triage ofwomen with minor cervical cytologic abnormalities in northern Thailand. An increase of the cut-off thresholdfor HC2 triage is not recommended in this region.