The Distribution Of Myofibroblasts In Esophageal Carcinoma And Its Possible Significance

Background and ObjectivesIt is only recently recognized that tumor progression is influenced by the tumormicroenvironment which is composed of extracellular matrix, blood vasculature, inflammatorycells and fibroblasts and produces an evolving crosstalk between different cell types within thetumor and its surrounding stroma tissue. What's more, tumor microenvironment, or tumorstroma, can also provide valuable information for diagnosis and prognosis of cancers.Recent studies have shown that myofibroblasts (MFs) are present in many carcinomas andmay play an important role in host response to invasive cancers. CD34- positive stromal cells arelost in invasive cancers while they are widely present in normal connective tissues. The aim ofour study was to explore the distribution of MFs and CD34~+ stromal cells in normal esophagus,squamous intraepithelial lesions (SILs) and esophageal squamous cell carcinoma (ESCC) byimmunohistochemistry technique and to establish the possible pathological significance of theirexpression in ESCC.Material and MethodsAll specimens were obtained from Pathology Department of Shantou University MedicalCollege, including 85 cases of ESCC, 12 cases of SILs,10 cases of normal esophagus(2 ofthem obtained from autopsy)Immunohistochemistry was performed for ASMA,hCD,CD34,CD31,CD3,CD20,CD68. Weregarded ASMA~+/hCD~- to be stromal myofibroblasts, and CD34~+/CD31~- to be stromalCD34-positive cells but not endothelial cells.The ASMA expression extensity was divided into three grade according to ASMA staining:negative (-), no cells express ASMA; slight (+):small number of cells express ASMA,scattered inconnection tissue; marked (++):large number of cells express ASMA, present in fascicular andreticular forms. Stromal inflammatory cells were marked by antibodies against CD3, CD20, and CD68 andwere accounted under high power field. Microvessels density (MVD) is measured by accountingthe number of microvessels stained with CD31 under high power fields.And the results was analyzed by SPSS to evaluate the relationship of the ASMAexpression with gross type, histological grade, lymphatic metastasis, invasion deep, MVD, andlymphatic infiltration.ResultsThe MFs exist only around submucosal gland in normal and SILs. CD34~+ stromal cellscan be found in all layers of esophageal wall, which seems to form bilayer structure with MFsaround the submucosal gland in mucous layer, exist among the smooth muscle cells in muscularlayer, and form fascicular and reticular pattern in fibrous layer. CD34~+ stromal cells proliferatein inflammatory area of SILs.In contrast, 90.6%of the ESCC cases (77/85)expressed the ASMA but CD34~+ stromal cellswere lost in invasive ESCC.The expression extensity of ASMA has correlations withlymphocyte infiltration negatively (P＜0.01) and MVD positively (P＜0.05).ConclusionProliferation of MFs and lost of CD34~+ stromal cells occurred in ESCC. The number ofMFs in stroma of ESCC is associated with lymphatic infiltration negatively and MVD positivelysuggesting that MFs maybe play an important role in restriction host immune response toanti-rumor and contribute to vasculogenesis of ESCC...