title: Tumour-infiltrating inflammation and prognosis in colorectal cancer: systematic review and meta-analysis.
abstract: 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.
  
  
  CONCLUSIONS
  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.
authors: Department of Colorectal Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China.
authors: Z
authors: Z
authors: Mei
authors: Department of Colorectal Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China.
authors: Y
authors: Y
authors: Liu
authors: Department of Colorectal Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China.
authors: C
authors: C
authors: Liu
authors: Department of Colorectal Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China.
authors: A
authors: A
authors: Cui
authors: Department of Colorectal Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China.
authors: Z
authors: Z
authors: Liang
authors: Department of Colorectal Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China.
authors: G
authors: G
authors: Wang
authors: Department of Colorectal Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China.
authors: H
authors: H
authors: Peng
authors: Department of Colorectal Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China.
authors: L
authors: L
authors: Cui
authors: Department of Biological Psychiatry, Shanghai Mental Health Centre, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China.
authors: C
authors: C
authors: Li
mesh_terms: D015179:Colorectal Neoplasms / Q000276:immunology / Q000473:pathology*; D018572:Disease-Free Survival; D006801:Humans; D007249:Inflammation / Q000473:pathology*; D016246:Lymphocytes, Tumor-Infiltrating / Q000276:immunology / Q000473:pathology*; D011379:Prognosis; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000473:pathology*