Background: In CCR, antigenic expression in primary tumors and also in metastatic lymphatic nodes (N+) may be useful for early detection of disease progression. The purpose of the present research was to establish the possible relationship among antigenic expression in tumor and N+ in order to disease free survival (DFS) and overall survival (OS) in CCR patients. Methods: A total of 90 CCR patients were studied: 90 primary CCR tumor samples and 64 lymphatic nodes; 22 samples from adenomas and normal colorectal mucosa specimens were employed as controls. Antigens studied were: MUC2, MUC1, MUC5AC, CEA, beta-catenin; carbohydrate antigens such as Lewis x (Lex), sialyl Lewis x (sLex), Lewis y (Ley), sialyl Lewis a (sLea) and Tn hapten. Immunohistochemistry was performed following standard procedures with antigenic retrieval. 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, immunohistochemical pattern and RI were analyzed employing Chi-Square test and ANOVA (p < 0.05), after data standardization. Results: Primary malignant 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%. In general, CCR showed a higher RI than control samples. Patients with a low Lex RI in primary tumor presented a longer DFS and OS than patients with a high Lex RI (44 vs. 26 months and 4.1 vs. 2.5 years, respectively). In N+ patients, Lex and sLex were also studied in lymphatic node; a low sLex RI was correlated with a longer DFS and OS than patients with a high sLex RI (44 vs. 14 months and 3.7 vs. 1.5 years, respectively), (p 0.07). In N+ with a low Lex RI presented a longer DFS than patients with a high Lex RI (24 vs. 18 months). Conclusions: This study showed that, in CCR patients, carbohydrate antigenic expression may indicate a difference in DFS and OS.
EACR Meeting, Oslo, Norway, May 2010 . Poster # 312