title: Clinicopathological significance of mucin production in patients with papillary cholangiocarcinoma.
abstract: BACKGROUND
  The clinicopathologic significance of mucin production in patients with papillary cholangiocarcinoma (PCC) is still controversial. We aimed at clarifying the similarities and differences between PCC cases with and without mucin secretion with regard to biological behavior and clinical course.
  
  
  METHODS
  Among 644 patients with surgically resected cholangiocarcinoma (1998-2011), 184 (28 %) patients were considered to have PCC and were enrolled in the study. Those patients were divided into two groups based on whether their PCC was mucin-producing (PCC-M, n = 89) or not (PCC-NM, n = 95). The presence of mucin secretion was determined by the cut surface of the specimens and by pathologic examination.
  
  
  RESULTS
  The clinicopathological features of PCC-M and PCC-NM largely overlapped. No significant between-group differences in malignant potential characteristics, including the depth of invasion, pathological T classification, and regional/periaortic lymph node metastasis, were observed (P = 0.193, 0.181, 0.083, and 0.674, respectively). However, a few clinicopathological differences existed between the two PCC types, i.e., the predominant histological type and epithelial subtype (P < 0.001 and P = 0.016, respectively). Immunohistochemically, MUC2, MUC5AC, MUC6, and HGM were more frequently expressed in PCC-M than PCC-NM (P < 0.002 in all). The disease-specific survival values were not significantly different between the two PCC types (PCC-M; 60 % at 5 year, PCC-NM; 46 %, P = 0.097).
  
  
  CONCLUSIONS
  PCC-M and PCC-NM were similar in morphology and prognosis. Although a few clinicopathological differences exist between them, their overlapping features and identical survival curves appear to justify the lack of a specific treatment modality for either type.
authors.affiliation: Division of Surgical Oncology, Department of Surgery, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Onoe
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Shimoyama
authors.forename: Tomoki
authors.initials: T
authors.lastname: Ebata
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Yokoyama
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Igami
authors.forename: Gen
authors.initials: G
authors.lastname: Sugawara
authors.forename: Takashi
authors.initials: T
authors.lastname: Mizuno
authors.forename: Shigeo
authors.initials: S
authors.lastname: Nakamura
authors.forename: Masato
authors.initials: M
authors.lastname: Nagino
mesh_terms: D000368:Aged; D001650:Bile Duct Neoplasms / Q000737:chemistry* / Q000473:pathology*; D001653:Bile Ducts, Intrahepatic; D018281:Cholangiocarcinoma / Q000737:chemistry* / Q000473:pathology* / Q000556:secondary; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D055271:Mucin 5AC / Q000032:analysis; D055262:Mucin-2 / Q000032:analysis; D055272:Mucin-6 / Q000032:analysis; D009077:Mucins / Q000032:analysis*; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D011379:Prognosis; D015996:Survival Rate
chemical_list: C524625:MUC2 protein, human; C524678:MUC5AC protein, human; C524734:MUC6 protein, human; D055271:Mucin 5AC; D055262:Mucin-2; D055272:Mucin-6; D009077:Mucins