Intestinal and pancreatobiliary differentiation in periampullary carcinoma: the role of immunohistochemistry.

Periampullary carcinoma (PC) is classified into intestinal and pancreatobiliary subtypes using morphology and immunohistochemistry (IHC). Different combinations of markers have been used in the literature. One hundred eight PCs were classified using morphology and IHC (CDX2, mucin [MUC] 2, cytokeratin [CK] 20, CK7, CK17, and MUC1). The expression of these markers was compared with different histologic subtypes, histopathologic prognostic parameters, and patients' survival. There were 38 intestinal and 53 pancreatobiliary subtypes classified on morphology alone. CDX2 showed high sensitivity (89.5%) and specificity (100%) for intestinal type. CK20 and MUC2 showed low sensitivity (50% and 39.5%) but high specificity (86.8% and 96.2%) for intestinal type. CK7 and CK17 showed a sensitivity of 90.5% and 32% and a specificity of 21% and 89.4%, respectively, for pancreatobiliary subtype. MUC1 was 100% sensitive but 0% specific in pancreatobiliary subtype. The overall median survival in morphologic and IHC intestinal type was 45 months versus 20 months in pancreatobiliary type (P = 0.01). Intestinal and pancreatobiliary types of PC were differentiated in 84.2% of cases by morphology alone and in 87.9% cases with IHC. CDX2-positive tumors had a median survival of 44 months versus 22 months in CDX2-negative tumors (P = .03). IHC helped in reclassifying an additional 4 cases of mixed and other types. Among the panel used, CDX2 showed a high sensitivity and specificity for intestinal subtype and was an independent prognostic marker for longer survival. Thus, CDX2 may be used routinely with morphology in subtyping of PC, and a panel of markers may be used in morphologically difficult cases.

Role of C-erbB2 expression in gallbladder cancer.

BACKGROUND: Gallbladder cancer (GBC) is a lethal malignancy presenting at an advanced stage. The pathogenesis is not well categorized, and surgery is the only treatment available at the early stage of the disease. There have been few reports on role of growth factor receptors in GBC. C-erbB2 is one such receptor whose over-expression is being explored in GBC as one of the factors involved in carcinogenesis and possible target for therapy. MATERIALS AND METHODS: One hundred and four consecutive cases of GBC were retrospectively studied with regard to clinical features, histological type, grade and stage of tumor. Immunohistochemistry for C-erbB2 was done and expression was correlated with different clinic-pathological parameters and survival. RESULTS: C-erbB2 overexpression was seen in 9.4% cases with complete staining and both complete and incomplete staining (2+ and 3+) was seen in 13.4% cases. Eighty percent of the C-erbB2 over-expressed cases were well differentiated and in stage II to stage IV disease. Dysplasia adjacent to carcinoma did not show any expression. No correlation was found with tumor grade, stage, gall stones, and patient survival. Xanthogranulomatous inflammation was inversely correlated with C-erbB2 over-expression. Median survival was 30 months in C-erbB2 over-expressed cases, and 12 months in C-erbB2 negative cases. CONCLUSION: We found complete membranous staining of C-erbB2 in 9.4% of GBC which was frequent in well differentiated and stage II to stage IV tumors. C-erbB2 tumors had longer median survival than C-erbB2 negative tumors. C-erbB2 is not involved early in the carcinogenetic process as none of the dysplasia showed expression. C-erbB2 over-expression may be considered as target for therapy in advanced stage of GBC.