ABSTRACT
BACKGROUND: Colorectal cancer (CRC) incidence in the Israeli population is higher in the Jewish population than among Arabs. MATERIALS AND METHODS: To determine the differences in demographic, clinical, histopathological and molecular characteristics of CRC between these two ethnic groups, 125 Arab patients treated at 3 community hospitals over a 20-year period were compared to a group of 208 consecutive Jewish patients. The mutator (replication error-positive [RER]) phenotype was detected by immunohistochemical evaluation of hMLH1 and hMSH2 protein expression in tumor tissue. RESULTS: The Arab patients were younger than the Jewish patients with a higher percentage of poorly-differentiated and mucinous cancers and a higher percentage of advanced stage cancers (Dukes' C+D) at presentation. The mutator phenotype was detected at similar rates in both ethnic groups. CONCLUSION: Our study demonstrated that CRC patients from two major ethnic populations in Israel, Arabs and Jews, differed in terms of the prevalence of the disease, pathological features and age at presentation, but not in frequency of mismatch-repair-positive cancers.
Subject(s)
Adenocarcinoma, Mucinous/pathology , Colorectal Neoplasms/epidemiology , Colorectal Neoplasms/pathology , Adaptor Proteins, Signal Transducing , Adenocarcinoma, Mucinous/epidemiology , Adenocarcinoma, Mucinous/metabolism , Age Factors , Aged , Arabs/ethnology , Carrier Proteins/biosynthesis , Cell Differentiation , Colorectal Neoplasms/metabolism , Female , Humans , Immunohistochemistry , Israel/epidemiology , Male , Middle Aged , MutL Protein Homolog 1 , MutL Proteins , Neoplasm Proteins/biosynthesis , Neoplasm Staging , Nuclear Proteins/biosynthesisABSTRACT
BACKGROUND: Angiogenesis is activated in numerous physiological and pathological conditions. We examined whether new vessel formation exists in the earliest stages of colonic tumorigenesis. MATERIALS AND METHODS: Microvascular density (MVD) was examined in 176 formalin-fixed and paraffin-embedded aberrant crypt foci (ACF) dissected from macroscopically-normal mucosa obtained from patients with colorectal cancer. ACF were classified as non-hyperplastic, non-dysplastic (NH-ACF, n = 80), hyperplastic (H-ACF, n = 72) and dysplastic (D-ACF, n = 24). Mucosal strips were stained with methylene blue solution and screened under x 40 magnification for ACF. The identified ACF were microdissected and stained with an anti-CD-34 monoclonal antibody. MVD in ACF were compared to that of normal corresponding mucosa. RESULTS: The mean MVD for normal mucosa and ACF were 13.7 +/- 7.7 and 23 +/- 13, respectively. Microvessel counts increased in NH-ACF versus normal mucosa (18.7 +/- 10 vs. 13.7 +/- 7.7, p = 0.05), in H-ACF versus NH-ACF (24.8 +/- 14 vs. 18.7 +/- 10, p = 0.002) and in D-ACF versus H-ACF (31.7 +/- 10 vs. 24.8 +/- 14, p = 0.014). We further evaluated the effect of low-dose aspirin on MVD in ACF. No effect of aspirin on microvessel counts could be detected. CONCLUSION: Our data suggest that angiogenesis occurs in ACF which are the earliest morphologically identifiable preneoplastic and early neoplastic lesions in colonic mucosa. With progression from NH-ACF to D-ACF there is a progressive, statistically significant increase in MVD, suggesting active angiogenesis during the earliest steps of colorectal tumorigenesis.
