Comparison of HPV genotypes and viral load between different sites of genital tract: the significance for cervical cancer screening.

OBJECTIVES: To compare the consistency of HPV genotype and viral loads among different sites within the female genital tract, and to correlate these with clinical outcomes. METHODS: 2646 previously unscreened rural women were enrolled in this population-based, cross-sectional study between May 2006 and April 2007. Physician-collected samples from lower vagina, upper vagina, cervix, and one self-collected sample were taken from each woman. Viral load was assessed by HC2 using the relative light unit/cutoff ratio (RLU/CO), and HPV genotyping was tested by Linear Array. RESULTS: The low risk HPV positive rate was highest in lower vagina samples and lowest in cervix samples. Overall kappa values of high risk HPV types between various anatomic sampling sites showed substantial or almost perfect agreement among women with normal pathology, CIN1, and CIN2+. In the CIN2+ population, high risk HPV viral load for cervix samples (557.25 RLU/CO) were much higher than upper vagina samples (96.43 RLU/CO, P<0.001), lower vagina samples (36.51 RLU/CO, P<0.001), and self-collected (206.83RLU/CO, P=0.003) samples. CONCLUSIONS: Although the distribution of high risk HPV genotypes was fairly equivalent across different genital sites, particularly for CIN2+ lesions, viral loads were largely variable. The findings may affect the cervical cancer screening methods using self-collected samples, particularly in resource-challenged areas.

Pooled analysis of the performance of liquid-based cytology in population-based cervical cancer screening studies in China.

BACKGROUND: Liquid-based cytology (LBC) has been widely used for cervical cancer screening. Despite numerous studies and systematic reviews, to the authors' knowledge few large studies to date have focused on biopsy-confirmed cervical lesions and controversy remains concerning its diagnostic accuracy. The objective of the current study was to assess LBC for detecting biopsy-confirmed cervical intraepithelial neoplasia (CIN) and cancer. METHODS: A pooled analysis of LBC using data from 13 population-based, cross-sectional, cervical cancer screening studies performed in China from 1999 to 2008 was performed. Participants (n = 26,782) received LBC and human papillomavirus testing. Women found to be positive on screening were referred for colposcopy and biopsy. The accuracy of LBC for detecting biopsy-confirmed CIN of type 2 or worse (CIN2+) as well as CIN type 3 or worse (CIN3+) lesions was analyzed. RESULTS: Of 25,830 women included in the analysis, CIN2+ was found in 107 of 2612 with atypical squamous cells (4.1%), 142 of 923 with low-grade squamous intraepithelial neoplasia (15.4%), 512 of 784 with high-grade squamous intraepithelial neoplasia (65.3%), 29 of 30 with squamous cell carcinoma (96.7%), 4 of 27 with atypical glandular cells (14.8%), and 85 of 21,454 with normal cytology results (0.4%). No invasive cancers were found to have atypical squamous cells, atypical glandular cells, or cytologically normal slides. The overall sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of LBC for detecting CIN2+ were 81.0%, 95.4%, 38.3%, 99.3 %, and 94.9%, respectively. Although Hybrid Capture 2 was more sensitive than LBC, the specificity, positive predictive value, and overall accuracy of LBC were higher than those of Hybrid Capture2 at 85.2%, 18.6%, and 85.5%, respectively. CONCLUSIONS: The results of the current study indicate that the performance of LBC can effectively predict the risk of existing CIN2+ and may be a good screening tool for cervical cancer prevention in a developing country.