Semi-Quantitative HPV Viral Load Estimation In Colposcopy Practice: A Pooled Analysis Among Chinese Population

Li ZHANG, National Cancer Center, Cancer Hospital of Chinese Academy of Medical Sciences & Peking Union Medical College, China
HU S. 1 , ZHANG Q. 1 , FENG R. 1 , REZHAKE R. 1 , ZHAO X. 1 , CHEN F. 1 , ZHANG X. 2 , PAN Q. 3 , ZHAO F. 1 , QIAO Y. 1

1 Department of Epidemiology,National Cancer Center, Cancer Hospital of Chinese Academy of Medical Sciences & Peking Union Medical College
2 Department of Pathology, National Cancer Center, Cancer Hospital of Chinese Academy of Medical Sciences & Peking Union Medical College
3 Department of Cytopathology, National Cancer Center, Cancer Hospital of Chinese Academy of Medical Sciences & Peking Union Medical College

Purpose To evaluate the role of high human papillomavirus (HPV) viral load in detection of the cervical cancer and precancer lesions (CIN2+) which were missed by cloposcopy in HPV positive women.
Methods We analyzed the pooled database of 17 population-based cross-sectional studies which were conducted across China from 1999 to 2008. In total, 30,371 women aged 17-59 participated in these studies and received liquid-based cytology test (LBC), HPV testing and visual inspection with acetic acid (VIA). Women with any positive result were referred to colposcopy, among them, 15,287 women with completed HPV testing and cloposcopy examination were included in the analysis. HPV positive women were categorized into three groups (low, intermediate and high viral load) based on relative light unit/ cut off ratios. The risk of CIN2+ and the correlation between viral load and the grading of cloposcopy were analyzed with the golden standard of pathological diagnosis .
Results 10652, 1661, 1369 and 1590 women were categorized into the groups of RLU< 1, 1-10, 10-100 and 100+, respectively. 34.7% (307/886) of CIN2+ and 30.0% (138/460)of CIN3+ cases were missed by colposcopy, respectively. The majority (84.7% of CIN2+, 87.7% of CIN3+) were categorized into the intermediate and high viral load groups. Risk of CIN2+ for women with intermediate and high viral load was 74.8 and 174.0 times higher than that of HPV negative women, respectively, even their colposcopy results were apparently normal.
Conclusions About one third cervical cancer and precancer lesions might be missed by colposcopy among Chinese screening population. The HPV viral load could assist to improve the detection of lesions in colposcopy practice based on the high risk of CIN2+ estimated for these women with intermediate and high HPV viral load, even they have normal colposcopy impression.
 
Funding source National Natural Science of Foundation of China (No 81322040)