Lack of healing reaction in the cancer wound.

Surgical wounds in cancer patients have a relatively high dehiscence rate. Although cancer resections are performed so as to include macroscopically non-involved tissues, some cancer cells can be present in the line of transection or surrounding tissues (R1 and R2 resections). The local healing process may facilitate proliferation of these localized cancer cells, and the high cytokine concentration within the healing wound may also attract cancer cells from distant sites to migrate into the wound area. The question arises how the tumor environment influences the wound healing process. The aim of the study was to monitor and compare, using immunohistochemical methods, the healing process of an incision wound performed through a metastatic liver tumor of colon cancer with the healing of a normal liver incision wound. The experiments were carried out on a CC531 colon cancer rat model. We observed impaired healing of cancer wounds at all stages of wound healing. Significantly fewer mononuclear cells infiltrated the cancer than the normal liver wounds. There were no significant differences in the phenotypes of infiltrating mononuclear cells. BrdU incorporation showed rapid proliferation of cancer but not infiltrating cells or fibroblasts in the cancer wounds. We observed no connective tissue formation and poor collagen deposition in cancer wounds. Additionally, cancer wounds were significantly deprived of newly formed vessels. We confirmed that the impaired migration and proliferation of inflammatory cells in cancer wounds and poor scar tissue formation contribute to impaired healing of cancer 'contaminated' wounds.