Abstract

Background: Different morfologic features (MF) are associated with a poor prognosis. The aim of this research was to relate MF with antigenic expression. Methods: 90 primary CCR tumor samples (69% were colonic and 31% rectal cancer), 64 lymphatic nodes (LN) and 22 control samples (adenomas and normal colorectal mucosa). MF were: localization, type, extent of local invasion, histologic and nuclear grade, vascular and lymphatic invasion and metastatic nodes (N+). Antigens studied were: MUC2, MUC1, MUC5AC, CEA, beta-catenin; carbohydrate antigens: Lewis x (Lex), sialyl Lewis x (sLex), Lewis y (Ley), sialyl Lewis a (sLea) and Tn hapten. Standard haematoxilyn/eosin and immunohistochemistry (IH) was performed. Positive response was evaluated by means of frequency analysis (p < 0.05). A reactivity index (RI) was calculated as intensity (I) x percentage of positive area (A); RI values varied from 0-12; low (0-6) and high (7-12). Intensity, percentage of positive area, IH pattern and RI were analyzed employing Chi-Square test and ANOVA (p < 0.05). Results: 65% corresponded to pure adenocarcinoma, 23% with mucinous component, 12% pure mucinous. Local invasion was detected: muscular in 96%, subserosal in 16%, serosal in 7% and fat in 37% while 31/64 (48%) LN showed metastatic invasion. Antigenic expression: CCR samples expressed MUC2 in 52% of cases; MUC1, 94%; MUC5AC, 14%; CEA, 93%; beta-catenin, 98 %; Lex, 74%; sLe x, 66%, Ley; 91%; sLea, 90% and Tn, 41%. N+ expressed MUC2, 30%; MUC1, 89%; MUC5AC, 19%; CEA, 80%; beta-catenin, 83%; Lex, 69%; sLex, 72%; Ley, 75%; sLea, 86% while Tn, 44%. A positive significant correlation was found between tumor type and antigenic expression: pure adenocarcinoma and CEA, adenocarcinoma with mucinous component and sLea and beta-catenin, pure mucinous carcinoma and Tn hapten and MUC2. Moreover, a positive tendency was found between muscular invasion and Ley and sLex while a positive significant correlation was found between well differentiated tumors and CEA and beta-catenin; a negative significant correlation between nuclear grade and beta-catenin. Conclusions: This study revealed correlations among antigenic expression and MF that may be important considering CCR patient prognosis.