Okamoto M, Azuma K, Hoshino T, Imaoka H, Ikeda J, Kinoshita T, Takamori S, Ohshima K, Edakuni N, Kato S, Iwanaga T, Aizawa H. Correlation of decreased survival and IL-18 in bone metastasis.
Intern Med 2009;
48:763-73. [PMID:
19443970 DOI:
10.2169/internalmedicine.48.1851]
[Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
OBJECTIVE
Previous studies have reported that serum IL-18 levels are increased in some cancers. We investigated whether IL-18 production is increased in sera and cancer cells of patients with non-small cell lung cancer (NSCLC).
PATIENTS OR MATERIALS
Serum levels of IFN-gamma and IL-18 and thioredoxin 1 (TRX1) were measured in 79 patients (51 males, 28 females, median age 67 years) with advanced NSCLC (57 adenocarcinoma, 22 squamous cell carcinoma; TNM stages IIIA [n=11], IIIB [n=24], and IV [n=44]) and 75 healthy age-matched controls (44 males, 31 females, median age 65 years) by enzyme-linked immunosorbent assay. We examined IL-18 production in the lungs and sites of bone metastasis of adenocarcinoma by immunohistochemistry.
RESULTS
Serum IL-18, IFN-gamma, and TRX1 levels in NSCLC patients were significantly (p<0.0001, p=0.0031, and p<0.0001, respectively) higher than in control subjects, while serum IFN-gamma levels in NSCLC were slightly increased. Serum IL-18, but not IFN-gamma or TRX1, levels were significantly (p=0.0102) and negatively associated with overall survival in NSCLC. The serum IL-18 level was identified as an independent prognostic factor for overall survival in multivariate survival analysis. Moreover, serum IL-18 levels were significantly (p=0.049) higher in NSCLC with bone metastasis than in NSCLC without bone metastasis. Based on immunohistochemistry, we observed that cancer cells in the lungs and bone metastases markedly produced IL-18.
CONCLUSION
Our results suggest that elevated serum IL-18 levels may be associated with IL-18 producing cancer cells in advanced NSCLC.
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