title: Prognostic significance of p27Kip1, p45Skp2 and Ki67 expression profiles in Merkel cell carcinoma, extracutaneous small cell carcinoma, and cutaneous squamous cell carcinoma.
abstract: OBJECTIVE
  To compare the immunohistochemical expression of prognostic markers p27(Kip1), p45(Skp2) and Ki67 in Merkel cell carcinoma (primary neuroendocrine carcinoma of the skin, MCC), small cell neuroendocrine carcinoma of lung and urinary bladder (SNC), and cutaneous squamous cell carcinoma (SCC).
  
  
  RESULTS
  Immunohistochemistry was performed using antibodies directed against p27(Kip1), p45(Skp2) and Ki67 on 72 tumour cases: 24 MCC, 25 SCC, and 23 SNC (15 from the lung and eight from the urinary bladder). Percentages of positive cells were determined for each marker and statistically analysed. Expression profiles on MCC and SCC were significantly different for all three markers. MCC and SNC exhibited significant similarities in their p27(Kip1) and p45(Skp2) expression profiles. In contrast, MCC and SNC differed significantly in their Ki67 proliferation indices, which were much higher in SNC. Additionally, MCC cases showed an association between increased proliferation indices and the appearance of local recurrence(s) and/or metastases.
  
  
  CONCLUSIONS
  The immunohistochemical profile of MCC differs from that of SCC, in spite of their common oncogenesis and the supposed metaplastic origin of MCC, and resembles that of SNC, except for Ki67 levels, which were higher in the latter (characterized by greater biological aggressiveness). High levels of Ki67 also appear to be a prognostic factor in MCC.
authors.affiliation: Department of Pathology, Hospital Universitari Germans Trias i Pujol, Catalonia, Spain. mtferfig@ns.hugtip.scs.es
authors.forename: M T
authors.initials: MT
authors.lastname: Fernández-Figueras
authors.forename: L
authors.initials: L
authors.lastname: Puig
authors.forename: E
authors.initials: E
authors.lastname: Musulen
authors.forename: M
authors.initials: M
authors.lastname: Gilaberte
authors.forename: C
authors.initials: C
authors.lastname: Ferrándiz
authors.forename: E
authors.initials: E
authors.lastname: Lerma
authors.forename: A
authors.initials: A
authors.lastname: Ariza
mesh_terms: D000704:Analysis of Variance; D014408:Biomarkers, Tumor / Q000096:biosynthesis*; D015266:Carcinoma, Merkel Cell / Q000378:metabolism / Q000473:pathology*; D018288:Carcinoma, Small Cell / Q000378:metabolism / Q000473:pathology*; D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000473:pathology*; D002352:Carrier Proteins / Q000096:biosynthesis; D050760:Cyclin-Dependent Kinase Inhibitor p27; D006801:Humans; D007150:Immunohistochemistry; D047908:Intracellular Signaling Peptides and Proteins; D019394:Ki-67 Antigen / Q000096:biosynthesis; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local; D011379:Prognosis; D044786:S-Phase Kinase-Associated Proteins / Q000096:biosynthesis; D012878:Skin Neoplasms / Q000378:metabolism / Q000473:pathology*
chemical_list: D014408:Biomarkers, Tumor; C436291:CDKN1B protein, human; D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; D019394:Ki-67 Antigen; D044786:S-Phase Kinase-Associated Proteins; D050760:Cyclin-Dependent Kinase Inhibitor p27