title: MUC5AC expression correlates with invasiveness and progression of extramammary Paget's disease.
abstract: BACKGROUND
  Patients with in situ extramammary Paget's disease (EMPD) tend to have a good prognosis, although dermal invasion and metastasis are associated with significantly increased morbidity and mortality. Previous studies have addressed mechanisms underlying the EMPD pathogenesis; however, no molecular markers that reflect invasiveness or progression have been established.
  
  
  OBJECTIVE
  This study aims to identify a reliable marker for predicting the risk of invasion and metastasis in EMPD.
  
  
  METHODS
  We performed an initial microarray screening for in situ, invasive or metastatic lymph node lesions of EMPD. We analysed 44 specimens from 38 primary EMPD cases by immunohistochemical staining.
  
  
  RESULTS
  We found that expressions of MUC5AC directly correlate with invasion and prognosis. Labelling rates of tumour cells were scored by staining intensity on a four-tiered scale (- to 3+) to investigate the correlation between the expression score of these molecular markers and the type of EMPD lesion. All the specimens scored positive (3+) for MUC1 and negative (-) for MUC6. MUC5AC expression was detected in 19 of 44 (43.2%) specimens. Invasive lesions and metastatic lymph nodes tended to express MUC5AC significantly higher than in situ lesions (P < 0.01). MUC2 was positive in 10 specimens (22.7%). There was no significant difference between the degree of MUC2 expression and invasiveness.
  
  
  CONCLUSIONS
  The degree of MUC5AC expression may correlate with the invasiveness and progression of EMPD, and may be a useful marker for identifying high-risk EMPD cases.
authors.affiliation: Department of Dermatology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Hata
authors.forename: R
authors.initials: R
authors.lastname: Abe
authors.forename: D
authors.initials: D
authors.lastname: Hoshina
authors.forename: N
authors.initials: N
authors.lastname: Saito
authors.forename: E
authors.initials: E
authors.lastname: Homma
authors.forename: S
authors.initials: S
authors.lastname: Aoyagi
authors.forename: H
authors.initials: H
authors.lastname: Shimizu
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics*; D018450:Disease Progression; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D008875:Middle Aged; D055271:Mucin 5AC / Q000235:genetics*; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis; D010145:Paget Disease, Extramammary / Q000235:genetics* / Q000473:pathology*; D018570:Risk Assessment
chemical_list: D014408:Biomarkers, Tumor; C524678:MUC5AC protein, human; D055271:Mucin 5AC