title: A basal membrane-like structure surrounding tumour nodules may prevent intraepithelial leucocyte infiltration in colorectal cancer.
abstract: Epithelial tumours consist of an epithelial compartment and a stromal compartment, which are sometimes separated by a basal membrane-like structure. We sought to determine whether these factors have prognostic value in 84 curatively resected stage II and III colorectal cancer by immunohistochemically staining tumours for leucocytes (CD45) and extracellular matrix, and to assess the presence of a basal membrane-like structure. Leucocyte infiltration was also assessed in hematoxylin-eosin (HE) stained sections. Most leucocytes were located in the tumour stroma. A relatively high intraepithelial leucocyte infiltration was significantly correlated with a lower level of tumour recurrence (P=0.03) and a longer disease-free survival (P=0.05), whereas leucocytes located in the tumour stroma (P=0.92) or at the advancing margin (p=0.06) were not. Intraepithelial leucocyte infiltration was also significantly correlated with leucocyte infiltration in the tumour stroma (P=0.02) and at the advancing tumour margin (P=0.005), and as assessed in HE-stained tumour sections (P=0.05), but each of these parameters on its own did not have a prognostic value in predicting disease-free survival. Moreover, the presence of a basal membrane-like structure surrounding the tumour epithelium was inversely correlated with the number of intraepithelial leucocytes (P=0.05), suggesting that this membrane-like structure functions as a barrier to intraepithelial leucocyte infiltration. We conclude that leucocytes must be in the direct vicinity of tumour cells to affect tumour growth. The presence of an extracellular matrix barrier seems to prevent this interaction.
authors.affiliation: Department of Surgery, K6-R, Leiden University Medical Center, PO Box 9600, 2300 RC, Leiden, The Netherlands.
authors.forename: Anand G
authors.initials: AG
authors.lastname: Menon
authors.forename: Gert Jan
authors.initials: GJ
authors.lastname: Fleuren
authors.forename: Ellen A
authors.initials: EA
authors.lastname: Alphenaar
authors.forename: Liesbeth E
authors.initials: LE
authors.lastname: Jonges
authors.forename: Connie M
authors.initials: CM
authors.lastname: Janssen van Rhijn
authors.forename: N Geeske
authors.initials: NG
authors.lastname: Ensink
authors.forename: Hein
authors.initials: H
authors.lastname: Putter
authors.forename: Rob A E M
authors.initials: RA
authors.lastname: Tollenaar
authors.forename: Cornelis J H
authors.initials: CJ
authors.lastname: van de Velde
authors.forename: Peter J K
authors.initials: PJ
authors.lastname: Kuppen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002462:Cell Membrane / Q000473:pathology; D015179:Colorectal Neoplasms / Q000276:immunology* / Q000401:mortality / Q000473:pathology; D018572:Disease-Free Survival; D004848:Epithelium / Q000473:pathology; D005260:Female; D006801:Humans; D017493:Leukocyte Common Antigens / Q000032:analysis; D007962:Leukocytes / Q000502:physiology*; D016246:Lymphocytes, Tumor-Infiltrating / Q000276:immunology; D008297:Male; D008875:Middle Aged; D011379:Prognosis
chemical_list: D017493:Leukocyte Common Antigens