[Role of HPV viral loads in random biopsy under normal colposcopy]

Objective: To explore the role of HPV viral loads in random biopsy under normal colposcopy. Methods: 908 atypical squamous cells of undetermined significance (ASC-US) and HPV positive women, recruited in cluster sampling in 9 provinces including 5 urban areas and 9 rural areas in China from 1999 to 2008 and meeting the inclusion and exclusion criteria were included in this analysis. According to relative light units/cutoff (RLU/CO) value, subjects were stratified as low (286 cases), intermediate (311 cases) and high (311 cases) viral load groups. Risks of cervical intraepithelial neoplasia grade 3 or worse (CIN3+) among different viral load groups were compared with linear trend Chi-square test. Results: Detection rate of CIN3+ in low, intermediate and high viral load groups were 2.1% (6 cases), 2.6% (8 cases) and 6.8% (21 cases) (Chi-square test for trend χ(2)=8.91, P=0.003) and were 60.3, 74.0 and 201.3 times higher than ASC-US and HPV negative women, respectively. Among 908 subjects, 27.0% (245 cases) were abnormal under colposcopy and 68.6% (623 cases) diagnosed as normal. Under normal colposcopy, detection rate of CIN3+ in low, intermediate and high viral load groups were 0.9% (2 cases), 0.9% (2 cases) and 3.8% (7 cases) (χ(2)=6.42, P=0.040). Conclusion: HPV viral loads display satisfactory risk stratification ability among ASC-US and HPV positive women under normal colposcopy. Women with high HPV viral loads show a significantly increased detection rate of existing CIN3+ and could be recommended to perform random biopsy for histologic diagnosis.