COLONIC ENDOCRINE-CELLS IN RECTAL-CARCINOMA, WITH PARTICULAR REGARD TO PREOPERATIVE IRRADIATION

Colonic endocrine cells in patients with rectal carcinoma with and wit hout preoperative irradiation were investigated by immunocytochemistry and image analysis. Somatostatin- and serotonin-immunoreactive cells in the colon of patients with rectal carcinoma, not irradiated preoper atively, were significantly fewer than in controls and patients who un derwent preoperative irradiation. There was no statistical difference between patients with rectal carcinoma following preoperative irradiat ion, and controls, regarding somatostatin- and serotonin-immunoreactiv e cell counts. Nor was there any statistical difference between contro ls and patients with or without preoperative irradiation regarding num bers of peptide YY (PYY)-, pancreatic polypeptide (PP)-, and enteroglu cagon-immunoreactive cells. The Cell Secretory Index ''CSI'' (an index indicating the cellular content of immunoreactive peptide/amine) of P P-immunoreactive cells in the colon of patients following preoperative irradiation,vas lower than controls and in patients with preoperative irradiation. There was no statistical difference between controls and patients,vith preoperative irradiation regarding the CSI of PP-immuno reactive cells, nor was there any statistical difference between contr ols and patients with or without preoperative irradiation regarding PY Y-, enteroglucagon-, somatostatin-, and serotonin-immunoreactive cells . It was concluded that somatostatin and serotonin may well be involve d in the development and growth of rectal carcinoma. It is suggested t hat the present observations may have implications for the management and treatment of colorectal carcinoma.