Tumour-infiltrating inflammation and prognosis in colorectal cancer: systematic review and meta-analysis

Br J Cancer. 2014 Mar 18;110(6):1595-605. doi: 10.1038/bjc.2014.46. Epub 2014 Feb 6.


Background: The role of tumour-infiltrating inflammation in the prognosis of patients with colorectal cancer (CRC) has not been fully evaluated. The primary objective of our meta-analysis was to determine the impact of tumour-infiltrating inflammation on survival outcomes.

Methods: Ovid MEDLINE and EMBASE were searched to identify studies reporting the prognostic significance of tumour-infiltrating inflammation for patients with CRC. The primary outcome measures were overall survival (OS), cancer-specific survival (CS) and disease-free survival (DFS).

Results: A total of 30 studies involving 2988 patients were identified. Studies were subdivided into those considering the associations between CRC survival and generalised tumour inflammatory infiltrate (n=12) and T lymphocyte subsets (n=18). Pooled analyses revealed that high generalised tumour inflammatory infiltrate was associated with good OS (HR, 0.59; 95% CI, 0.48-0.72), CS (HR, 0.40; 95% CI, 0.27-0.61) and DFS (HR, 0.72; 95% CI, 0.57-0.91). Stratification by location and T lymphocyte subset indicated that in the tumour centre, CD3+, CD8+ and FoxP3+ infiltrates were not statistically significant prognostic markers for OS or CS. In the tumour stroma, high CD8+, but not CD3+ or FoxP3+ cell infiltrates indicated increased OS. Furthermore, high CD3+ cell infiltrate was detected at the invasive tumour margin in patients with good OS and DFS; and high CCR7+ infiltrate was also indicated increased OS.

Conclusion: Overall, high generalised tumour inflammatory infiltrate could be a good prognostic marker for CRC. However, significant heterogeneity and an insufficient number of studies underscore the need for further prospective studies on subsets of T lymphocytes to increase the robustness of the analyses.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't
  • Review
  • Systematic Review

MeSH terms

  • Colorectal Neoplasms / immunology
  • Colorectal Neoplasms / pathology*
  • Disease-Free Survival
  • Humans
  • Inflammation / pathology*
  • Lymphocytes, Tumor-Infiltrating / immunology
  • Lymphocytes, Tumor-Infiltrating / pathology*
  • Prognosis
  • T-Lymphocyte Subsets / immunology
  • T-Lymphocyte Subsets / pathology*