DIFFERENCES IN AGNOR QUANTITY BETWEEN COLORECTAL-CANCER AND CORRESPONDING METASTASES - ARE THEY USEFUL FOR PROGNOSTIC PURPOSES

In order to evaluate the relationships between primary colorectal aden ocarcinomas and their metastases with regard to AgNOR proteins express ion, we have performed a morphometric analysis of AgNOR silver precipi tates (AgNORs) in advanced colorectal carcinomas (stage III-IV) as wel l as in corresponding lymph node and distant metastases. Surgical spec imens studied consisted of 64 primary tumours, 56 lymph node and 43 he patic or omental metastases; for each formalin-fixed paraffin-embedded specimen, silver staining according Ploton et al. (1986) was performe d and the AgNOR area (NORA) relative to primary site, lymph node and/o r distant metastases was calculated. A significant difference (P<0.001 ) among the nonneoplastic colonic control mucosae and primary or metas tatic neoplastic lesions was found, but no statistically significant d ifferences were encountered among the categories of primary colorectal carcinomas and their lymph node or distant metastases. Moreover, on t he basis of NORA data case per case, three groups of patients were sel ected. In particular, in the group 1 NORA values of metastases were hi gher than those of the corresponding primary carcinomas, while in the group 2, NORA values of metastases were lower than those of the corres ponding primary neoplasms; no differences of NORA values were encounte red in group 3. The cumulative patient survival estimated by the Kapla n-Meier method showed a worse prognosis for patients belonging to grou p 1, where higher AgNOR values, not only in primary carcinomas but als o in lymph node and distant metastases, were found.