The effect of surgical wounding on tumour development.

For more than a century, a role for wound healing in the outgrowth of tumours has been implied based on observations in both experimental and clinical studies. Wound healing can be divided into stages of inflammatory, proliferative, repair and remodelling processes. Through proper regulation of activation of epithelial, endothelial and inflammatory cells, platelets and fibroblasts, and the production of growth factors, wounds heal and the various cell types resume their normal function. In tumour growth, similar processes of cell activation and growth factor production are observed. These processes are, however, differently regulated leading to ongoing cellular activation. In recent years, growth factors such as EGF, TGF-alpha and TGF-beta, bFGF, IGF I and II, and PDGF have been identified to play a role in the different stages of wound healing. In addition, some of these factors have now been identified as also being involved in the outgrowth of tumours. In this review, cell types involved in wound healing and tumour growth, as well as the growth factors and cytokines they produce and the role of the extracellular matrix, extensively present in both conditions, are being discussed. A better understanding of the time interval during which the sequelae of events in wound healing occur in relation to the time interval of tumour recurrence may be the basis for defining new therapeutic strategies that can interfere with tumour outgrowth without affecting wound healing processes. These new therapeutic approaches may be of importance especially after surgery or other invasive (diagnostic) procedures in cancer patients.