Therapeutic vaccination for non-small-cell lung cancer: a meta-analysis

Lung cancer is the most common malignancy worldwide in terms of incidence and mortality. The vast majority of cases (85-90%) are non-small-cell lung cancer (NSCLC). Immunotherapy consists of mainly therapeutic vaccination designed to induce or amplify the immune responses directed against tumor-associated antigens. However, there is no conclusion to date for its strengths and weaknesses. Assessing the objective efficacy and safety of the therapeutic vaccination for NSCLC patients will help to figure out the future development of therapeutic vaccination. We performed a meta-analysis of six randomized controlled trials including 2,239 patients (1,363 patients in the therapeutic vaccination group and 876 patients in the control group) with NSCLC. Quantitative analysis was carried out to evaluate overall survival (OS) and toxicity of therapeutic vaccination. The vaccine group had produced significant improvement in OS compared with the control group [hazard ratio (HR) 0.83, 95% (confidence interval) CI 0.76-0.91; Z = 3.79, P = 0.0002]. Subgroup analysis showed a more significant improvement of OS in the subgroup compared with the control group (HR 0.70, 95% CI 0.59-0.82; Z = 4.42, P < 0.00001). No increased incidence of adverse events was obtained in the therapeutic vaccination group compared with the control group. Therapeutic vaccination adds benefits to NSCLC patients and may become a standard complementary therapeutic approach in the future if the associated toxicity is reduced.