IMMUNOLOCALIZATION OF CRIPTOREGULIN AND AMPHIREGULIN IN RECTAL-CANCER- CORRELATION WITH PROGNOSIS

We have examined the expression of two newly identified members of the EGF family, cripto and amphiregulin (AR), in a series of 58 primary r ectal carcinomas and adjacent non-involved mucosa by immunohistochemic al staining using rabbit polyclonal antibodies. More than 90% (53/58) of rectal carcinomas showed AR immunoreactivity whereas cripto was fou nd in 41 out of 58 (71%) tumours. Cripto immunoreactivity was most fre quently seen in tumours arising in the lower third of the rectum (p<0. 01) and in flat and excavated lesions (p<0.05). Out of 54 normal recta l mucosae adjacent to carcinoma 20 (37%) showed cripto immunoreactivit y and all showed a trend towards a higher recurrence rate. Ten of thes e 20 (50%) rectal tumours showed less cripto immuno-reactivity than th e adjacent normal mucosa and were penetrating through the bowel wall a nd recurred within 5 years. There was a correlation between increased cripto immunoreactivity in the normal mucosa and lymph node involvemen t (p=0.01). AR immunoreactivity was present in the majority (52/58, 94 %) of the normal mucosae adjacent to tumours. No correlation was found between AR immunostaining, histology and prognosis.