Prevalence of human papillomavirus in patients with nasopharyngeal carcinoma: a meta-analysis

Background: The human papillomaviruses (HPVs) are causally associated with the tumorigenesis of several types of cancers. However, HPV prevalence in patients with nasopharyngeal carcinoma (NPC) has not previously been systematically reviewed. Therefore, we performed a meta-analysis to estimate the HPV prevalence in patients diagnosed with NPC and to assess the potential etiological significance of HPVs. The goal of this study was to quantitatively summarize published data to evaluate the effects of HPV infection on the pathogenesis of NPC. Methods: The PubMed, Embase, Web of Science, Science Direct, Ovid, Wiley Online Library, and Cochrane Library databases, as well as several Chinese databases (China National Knowledge Infrastructure (CNKI), Chinese Chong Qing VIP, Chinese Wan Fang and China Biology Medicine databases) were searched to identify all relevant studies. For case-control studies, the odds ratios (ORs) and 95% confidence intervals (CIs) were computed. For studies providing World Health Organization (WHO) classifications and HPV subtypes, the corresponding pooled ORs and 95% CIs were also calculated. The Stata 12.0 software was used for the Meta-analysis. Results: Thirty-nine studies were included in the meta-analysis, involving a total of 1748 cases of NPC and 289 control cases. The pooled HPV prevalence was 21% among all of the NPC patients (95% CI: 17%, 26%; I2=89.4%; P<0.001). A pooled OR of 4.77 (95% CI: 1.69, 13.45) was calculated based on the 11 case-control studies (I2=69.7%; P<0.001). Moreover, the prevalence of HPV was higher in cases outside of China than in cases from regions in China (23% vs 19%; I2=95.0%; P<0.001). The HPV prevalence was 33.6% (24/66) in patients with a WHO type I NPC, and 27.9% (115/402) in patients with a WHO type II/III NPC. The pooled OR of 2.638 (95% CI: 0.984, 7.072) was not statistically significant. In addition, the pooled prevalence of HPV16 and HPV18 were 10.5% and 1.9%, respectively, and the pooled OR was 2.26 (95% CI: 1.28, 3.99). Conclusions: Our study suggests that HPVs play a potential role in the pathogenesis of NPC. In addition, this study expands the knowledge of the molecular mechanisms underlying NPC tumorigenesis and suggests precautionary measures.