HPV and lung cancer risk: a meta-analysis.

The potential causal association between human papillomavirus (HPV) and lung cancer (LC) remains controversial. We performed this meta-analysis to evaluate whether HPV infection in lung tissue is associated with LC compared with non-cancer controls. We also quantified this association in different LC subtypes. MEDLINE, EMBASE and Web of Science were searched through March 2014, using the search terms "lung cancer", "human papillomavirus", "HPV" and their combinations. Association was tested using odds ratio (OR) with 95% confidence intervals (95% CI). Heterogeneity was assessed using Q and I(2) statistic. Finally, nine studies, for a total of 1094 LCs and 484 non-cancer controls, were identified as eligible publications. The pooled results showed that HPV infection was associated with LC (OR=5.67, 95% CI: 3.09-10.40, P<0.001). Similar results were also observed in HPV16 and/or HPV18 (HPV16/18) infection analyses (OR=6.02, 95% CI: 3.22-11.28, P<0.001). HPV16/18 was significantly associated with lung squamous cell carcinoma (SCC) (OR=9.78, 95% CI: 6.28-15.22, P<0.001), while the pooled OR was 3.69 in lung adenocarcinoma (95% CI: 0.99-13.71, P=0.052). Our results suggest that lung tissue with HPV infection has a strong association with LC, and especially, HPV16/18 infection significantly increases SCC risk, which indicates a potential pathogenesis link between HPV and LC.