Human papillomavirus infection as a prognostic marker for lung adenocarcinoma: a systematic review and meta-analysis

Although a number of studies have investigated the association between human papillomavirus (HPV) and lung cancer prognosis, the results remain inconsistent. We therefore conducted a meta-analysis of epidemiologic studies to address this issue. Searches of the MEDLINE and EMBASE electronic databases from their inception until June 30, 2016 yielded nine studies involving a total of 1,205 lung cancer cases that were used to conduct the meta-analysis. Study-specific risk estimates were pooled using a random-effects model. The pooled hazard ratio (HR) comparing HPV-positive to HPV-negative cancers 1.00 (95% confidence interval (CI): 0.78-1.28) was not significantly correlated with overall survival. However, lung adenocarcinoma patients with HPV infections exhibited a survival benefit compared to those without HPV infection (HR=0.69, 95% CI: 0.50-0.96). This meta-analysis suggests HPV infection is a prognostic marker in lung adenocarcinoma. To further elucidate the epidemiology and pathogenesis of HPV infections in lung cancer, future large prospective studies are encouraged to stratify survival analysis based on the pathological type and clinical stage of the cancer.