title: Differential protein immunoexpression profiles in appendiceal mucinous neoplasms: a special reference to classification and predictive factors.
abstract: Appendiceal mucinous neoplasms have been the focus of considerable debate in recent years. We histologically classified 70 appendiceal mucinous neoplasms into three categories: 32 mucinous adenoma, 23 mucinous neoplasm of uncertain malignant potential, and 15 mucinous adenocarcinomas. Immunohistochemistry was performed for 24 proteins in different functional categories, specifically, oncogenic proteins (bcl-2, beta-catenin, CEA, C-erbB2, c-kit, Cox-2, Cyclin D1, EGFR, Ki-67, NF-kappaB, VEGF), tumor suppressors (E-cadherin, FHIT, hMLH1, p53, p63, smad4), cell-cycle regulators (p21, p27, p16), and mucin proteins (MUC1, MUC2, MUC5AC, MUC6). Our data showed that 9 out of the 24 proteins were more frequently altered in the mucinous adenocarcinoma group than in the mucinous adenoma group (P<0.05), including beta-catenin (13% in mucinous adenoma vs 60% in mucinous adenocarcinoma), CyclinD1 (44 vs 87%), Ki-67 (high labeling index: 31 vs 67%), NF-kappaB (19 vs 60%), VEGF (16 vs 87%), E-cadherin (0 vs 47%), p53 (6 vs 40%), MUC2 (9 vs 67%), and MUC5AC (3 vs 40%). The distinct immunoexpression profile of mucinous neoplasm of uncertain malignant potential was placed between those of mucinous adenoma and mucinous adenocarcinoma (P<0.05). Moreover, the mucinous adenoma, mucinous neoplasm of uncertain malignant potential, and mucinous adenocarcinoma categories displayed differences in terms of the number of altered markers among the nine proteins (P<0.05; mean 1.4 vs 2.6 vs 5.5, respectively). In mucinous adenocarcinoma, the p53 status was related to disease-free survival and overall survival of patients (P<0.05, both). NF-kappaB status and the number of altered protein markers made statistically marginal impacts on disease-free survival; also beta-catenin loss, on overall survival of patients. In conclusion, protein immunoexpression profiles may facilitate the classification of appendiceal mucinous neoplasms. In our study, the three tumor categories of mucinous adenoma, mucinous neoplasm of uncertain malignant potential, and mucinous adenocarcinoma exhibited distinct immunoexpression profiles. Five and more altered protein markers, p53 overexpression, NF-kappaB positivity, and beta-catenin loss were predictive factors of adverse clinical outcomes in appendiceal mucinous adenocarcinomas.
authors.affiliation: Department of Pathology, Seoul National University Boramae Hospital, Seoul, Korea.
authors.forename: Sun Och
authors.initials: SO
authors.lastname: Yoon
authors.forename: Baek-hui
authors.initials: BH
authors.lastname: Kim
authors.forename: Hye Seung
authors.initials: HS
authors.lastname: Lee
authors.forename: Gyeong Hoon
authors.initials: GH
authors.lastname: Kang
authors.forename: Woo Ho
authors.initials: WH
authors.lastname: Kim
authors.forename: Young A
authors.initials: YA
authors.lastname: Kim
authors.forename: Je Eun
authors.initials: JE
authors.lastname: Kim
authors.forename: Mee Soo
authors.initials: MS
authors.lastname: Chang
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000145:classification / Q000235:genetics / Q000473:pathology*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001063:Appendiceal Neoplasms / Q000145:classification / Q000235:genetics / Q000473:pathology*; D014408:Biomarkers, Tumor / Q000032:analysis*; D002648:Child; D018291:Cystadenoma, Mucinous / Q000145:classification / Q000235:genetics / Q000473:pathology*; D018572:Disease-Free Survival; D005260:Female; D015870:Gene Expression; D020869:Gene Expression Profiling; D006801:Humans; D007150:Immunohistochemistry; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D016328:NF-kappa B / Q000096:biosynthesis / Q000235:genetics; D011379:Prognosis; D046888:Tissue Array Analysis; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis / Q000235:genetics; D055815:Young Adult; D051176:beta Catenin / Q000096:biosynthesis / Q000235:genetics
chemical_list: D014408:Biomarkers, Tumor; D016328:NF-kappa B; D016159:Tumor Suppressor Protein p53; D051176:beta Catenin