Human papillomavirus type-distribution in cervical cancer in China: the importance of HPV 16 and 18

Prophylactic vaccination against HPV 16 and 18 has the potential for effective prevention of high-grade precancer (cervical intraepithelial neoplasia [CIN)] 2/3) and ICC caused by these viruses (globally 50 and 70%, respectively) when employed in women prior to starting sexual activity. To provide data for decisions on HPV vaccination in China, we determined HPV type-distribution in ICC and CIN 2/3 from women of different regions within China. A multicenter study was conducted by randomized sampling of paraffin blocks of 664 ICC (630 squamous cell carcinoma [SCC]; 34 adenocarcinoma [ADC]), 569 CIN 2/3 cases from seven regions of China. Histological diagnosis was confirmed in 1,233 cases by consensus review. HPV DNA was detected using the SPF10 LiPA25 version 1 assay. HPV prevalence was 97.6% in SCC, 85.3% in adenocarcinoma, and 98.9% in CIN 2/3. HPV 16 (76.7%) and HPV 18 (7.8%) were the most common, together accounting for 84.5% of SCC, followed by HPV 31 (3.2%), HPV 52 (2.2%), and HPV 58 (2.2%). HPV positivity in SCC did not differ notably by region. However, SCC cases from women <= 34 years had higher HPV 16 positivity than women over 50 years, among whom HPV 52, 58, and 39 were more common. HPV 16 and 18 were under-represented, whereas HPV 31, 52, and 58 were over-represented in CIN2/3 compared to SCC. The potential impact of vaccines against oncogenic HPV types 16 and 18 is estimated to be high (84.5%) against total SCC. These data are critical for China's future evaluation of the cost-effectiveness of current cervical cancer vaccines and of HPV-based screening guidelines.