title: Expression of p63 is the sole independent marker of aggressiveness in localised (stage I-II) Merkel cell carcinomas.
abstract: Merkel cell carcinoma of the skin is a malignant neuroendocrine tumour, whose prognostic criteria are a matter of dispute. Specifically, no predictor is presently available in stage I-II tumours. We collected clinical and follow-up data from 70 Merkel cell carcinomas of the skin. The same cases were studied for p63 expression by immunohistochemistry, by reverse-transcription PCR (RT-PCR) and TP63 gene status by FISH and for presence of Merkel cell polyomavirus by PCR. Stage emerged as a significant prognostic parameter (P=0.008). p63 expression, detected in 61% (43/70) of cases by immunohistochemistry, was associated with both decreased overall survival (P<0.0001) and disease-free survival (P<0.0001). Variable expression patterns of the different p63 isoforms were found only in cases immunoreactive for p63. In these latter lesions, at least one of the N-terminal p63 isoforms was detected and TAp63α was the most frequently expressed isoform. TP63 gene amplification was observed by FISH in only one case. Presence of Merkel cell polyomavirus DNA sequences was detected in 86% (60/70) of Merkel cell carcinomas and did not emerge as a significant prognostic parameter. Merkel cell carcinoma cases at low stage (stage I-II) represented over half (40/70 cases, 57%) of cases, and the clinical course was uneventful in 25 of 40 cases while 15 cases died of tumour (10/40 cases) within 34 months or were alive with disease (5/40 cases) within 20 months. Interestingly, a very strict correlation was found between evolution and p63 expression (P<0.0001). The present data indicate that p63 expression is associated with a worse prognosis in patients with Merkel cell carcinoma, and in localised tumours it represents the single independent predictor of clinical evolution.
authors.affiliation: Department of Biomedical Sciences and Human Oncology, University of Torino, Torino, Italy. sofia.asioli@unito.it
authors.forename: Sofia
authors.initials: S
authors.lastname: Asioli
authors.forename: Alberto
authors.initials: A
authors.lastname: Righi
authors.forename: Dario
authors.initials: D
authors.lastname: de Biase
authors.forename: Luca
authors.initials: L
authors.lastname: Morandi
authors.forename: Virginia
authors.initials: V
authors.lastname: Caliendo
authors.forename: Franco
authors.initials: F
authors.lastname: Picciotto
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Macripò
authors.forename: Francesca
authors.initials: F
authors.lastname: Maletta
authors.forename: Ludovica Verdun
authors.initials: LV
authors.lastname: di Cantogno
authors.forename: Luigi
authors.initials: L
authors.lastname: Chiusa
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Eusebi
authors.forename: Gianni
authors.initials: G
authors.lastname: Bussolati
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis* / Q000235:genetics*; D015266:Carcinoma, Merkel Cell / Q000737:chemistry* / Q000235:genetics* / Q000401:mortality / Q000473:pathology / Q000628:therapy / Q000821:virology; D004279:DNA, Viral / Q000032:analysis; D018572:Disease-Free Survival; D005260:Female; D005784:Gene Amplification; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D007558:Italy; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D011120:Polyomavirus / Q000235:genetics; D016016:Proportional Hazards Models; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018570:Risk Assessment; D012307:Risk Factors; D012878:Skin Neoplasms / Q000737:chemistry* / Q000235:genetics* / Q000401:mortality / Q000473:pathology / Q000628:therapy / Q000821:virology; D015996:Survival Rate; D013997:Time Factors; D014157:Transcription Factors / Q000032:analysis* / Q000235:genetics*; D016896:Treatment Outcome; D025521:Tumor Suppressor Proteins / Q000032:analysis* / Q000235:genetics*
chemical_list: D014408:Biomarkers, Tumor; D004279:DNA, Viral; C115051:TP63 protein, human; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins