GASTRIN AND COLORECTAL-CANCER - WHERE NOW

Gastrin exerts a trophic influence on various regions of the gastroint estinal (GI) tract and this has led to an interest in its potential ro le in the growth of GI tumours, There is little evidence that elevated circulating levels of gastrin predispose to colonic tumours. However, the hormone can be detected within some colonic tumour tissues and a possible paracrine or autocrine role has been proposed. At present, ev idence for such a role is conflicting, as is the evidence that colonic tumour cells possess receptors for the mature hormone. Colonic tumour s have been found to contain much higher concentrations of incompletel y processed gastrin precursors such as glycine extended gastrin and re cent studies indicate that they may exert trophic effects mediated by specific receptors. Further studies of this are required, Whether spec ific hormone receptor antagonists will have a role in the clinical man agement of colonic tumours remains unclear. (C) 1998 Lippincott-Raven Publishers.