TREM-1 expression in tumor-associated macrophages and clinical outcome in lung cancer

Am J Respir Crit Care Med. 2008 Apr 1;177(7):763-70. doi: 10.1164/rccm.200704-641OC. Epub 2007 Dec 20.


Rationale: Triggering receptor expressed on myeloid cells (TREM)-1 is a molecule crucial for the triggering and amplification of inflammatory response and a new biomarker for sepsis. Tumor-associated macrophages and inflammation in the tumor microenvironment are also involved in cancer progression.

Objectives: To determine the role of TREM-1 in tumor-associated macrophage and cancer progression.

Methods: Using ELISA and Western blot, we measured soluble TREM-1 levels in 65 pleural effusions of various etiologies. We evaluated TREM-1-positive cells by immunocytochemistry in malignant pleural effusion and in lung tumor versus adjacent normal tissue in surgical specimens from 68 patients with non-small cell lung cancer (NSCLC). TREM-1 expression was correlated with patient survival. TREM-1 expression in primary isolated peripheral blood macrophages cocultured with lung cancer cell lines was determined by quantitative real-time reverse transcriptase-polymerase chain reaction.

Measurements and main results: Soluble TREM-1 and tumor-associated macrophage TREM-1 expression was increased in malignant pleural effusions in patients with NSCLC. Lung cancer cells could directly up-regulate TREM-1 and proinflammatory cytokine (tumor necrosis factor-alpha, IL-1beta) expression in primary isolated peripheral blood macrophages in coculture experiments. Increased TREM-1-positive tumor-associated macrophages in tumor tissue of patients with NSCLC were associated with reduced disease-free (P = 0.011) and overall survival (P = 0.004). Multivariate Cox regression analysis indicated that TREM-1 was an independent predictor of patient survival (hazard ratio, 2.72; 95% confidence interval, 1.33-5.57; P = 0.006).

Conclusions: Cancer cells can directly up-regulate TREM-1 expression in patients' macrophages. TREM-1 expression in tumor-associated macrophages is associated with cancer recurrence and poor survival of patients with NSCLC. TREM-1 and the inflammatory response may play an important role in cancer progression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carcinoma, Non-Small-Cell Lung / immunology*
  • Carcinoma, Non-Small-Cell Lung / pathology
  • Disease Progression
  • Female
  • Humans
  • Inflammation
  • Kaplan-Meier Estimate
  • Lung Neoplasms / immunology*
  • Macrophages / metabolism*
  • Male
  • Membrane Glycoproteins / metabolism*
  • Middle Aged
  • Multivariate Analysis
  • Pleural Effusion / immunology
  • Pleural Effusion / pathology
  • Prognosis
  • Proportional Hazards Models
  • Prospective Studies
  • Receptors, Immunologic / metabolism*
  • Triggering Receptor Expressed on Myeloid Cells-1
  • Up-Regulation*


  • Membrane Glycoproteins
  • Receptors, Immunologic
  • TREM1 protein, human
  • Triggering Receptor Expressed on Myeloid Cells-1