Inflammatory cytokines and non-small cell lung cancer in a CT-scan screening cohort: Background review of the literature

BACKGROUND: Inflammatory cytokines are at the intersection of tumor cell biology and host immune response. Peripheral cytokine expression levels may reflect the microscopic tumor milieu, and specific cytokines play an integral role in tumor initiation, growth, and metastasis. High-throughput cytoki ne analysis may identify panels for early-stage non-small cell lung cancer (NSCLC) diagnosis and identify individuals at high-risk for lung cancer with indeterminate lung nodules 8-20 mm in size. METHODS: Thirteen serum cytokines from the NYU Lung Cancer Biomarker Center cohort with early-stage NSCLC were analyzed using bead-based immunoassay technology. RESULTS: In the NYU cohort, a one unit increase in interferon-γ increased risk of lung cancer by 3% (OR = 1.03, 95% CI, 1.02-1.05) and a one unit increase in TNF-α decreased the risk of lung cancer by 53% (OR = 0.47, 95% Cl, 0.31-0.71) when both cytokines were included in a logistic regression model with adjustments for age and pack-years of smoking. The resulting AUC for the Receiver Operating Characteristic (ROC) curve was 0.88; the sensitivity and specificity at the optimal cutpoint were 78.9% and 90.3%, respectively. CONCLUSIONS: Cytokines have limited value in the early diagnosis of early-stage NSCLC. Our review of the literature suggests that although inflammation is important for the development of NSCLC, that cytokines are increased in more advanced lung cancer than when the diagnosis occurs at presentation.