The predictive value of the interferon-γ release assay for chemotherapy responses in patients with advanced non-small-cell lung cancer

Objectives IFN-γ takes part in immunologic responses to cancer and its interactions with chemotherapy have also been described. Our previous study had showed an association between phytohemagglutinin (PHA)-stimulated IFN-γ (PSIG) response and overall survival in patients with advanced non-small-cell lung cancer (NSCLC). Here, we aimed to evaluate the correlation between PSIG and chemotherapy responses. Materials and methods From January 2011 to August 2012, 340 newly diagnosed patients with lung cancer were enrolled in a prospective latent tuberculosis observational study. Patients with advanced NSCLC who were treated with chemotherapy were included in this analysis. An IFN-γ release assay (IGRA) was used to evaluate pre-treatment PSIG levels. Patients were grouped into low and high PHA response groups according to their PSIG levels. Their demographic characteristics, tumor responses, and survival rates were investigated. Results Eighty-four patients were enrolled. The chemotherapy response rates in the high and low PHA response groups were 45.2% and 35.7% (p = 0.190), respectively. The disease control rate in the high PHA response group was 76.2%, versus 52.4% in the low PHA response group (p = 0. 023). In multivariate analysis, PHA response was an independent predictor of disease control (odds ratio = 3.017, 95% confidence interval = 1.115–8.165). The Kaplan-Meier method demonstrated both longer progression-free survival (p = 0.008) and overall survival (p = 0.003) in the high PHA response group. Conclusions A higher pre-treatment PSIG response, obtained using the IGRA, was associated with better disease control rate and survival among patients with advanced NSCLC treated with chemotherapy.