title: Role of YAP-1 in Thyroid Tumor Progression and Outcome.
abstract: Yes-associated protein-1 (YAP-1) is a player of the Hippo pathway and is involved in regulating cell proliferation. YAP-1 is overexpressed in papillary and anaplastic thyroid cancers. However, a correlation between YAP-1 expression and outcome in thyroid carcinoma has not been conclusively demonstrated.
  
  
  
  This study was designed to clarify whether YAP-1 may be considered a marker of worse prognosis and outcome in thyroid cancer.
  
  
  
  A large series of cases of thyroid cancer with a long follow-up were investigated for YAP-1 expression.
  
  
  
  The study was carried out in the Pathology section of a referral Italian center for Endocrine Surgery and Endocrinology.
  
  
  
  The study included a consecutive series of 105 patients who underwent thyroidectomy from 1985 to 1992. The mean follow-up was 15 years. For all patients, clinicopathologic features were considered. All patients completed the study.The study also included a consecutive series of 52 patients who underwent thyroidectomy from 2012 to 2013 in order to analyze more deeply the correlation of YAP-1expression with BRAF mutation.
  
  
  
  The 105 thyroid tumors were immunohistochemically investigated for YAP-1 expression.
  
  
  
  We expected a correlation between YAP-1 expression and worse prognosis.
  
  
  
  Among 105 tumors, 77 scored positive for YAP-1 expression, of which 68 papillary thyroid carcinomas and 9 anaplastic thyroid carcinomas were YAP-1 positive. The correlation of YAP-1 expression with clinicopathologic characteristics was significant for the absence of a tumoral capsule, gender, and extrathyroid invasion.Interestingly, significant correlations were found between YAP-1 and both persistence of disease and death from carcinoma.
  
  
  
  The data show an association of YAP-1 expression with worse clinicopathologic features of thyroid tumors that seem to have a specific impact on outcome.
authors.affiliation: *Department of Medical Area, Azienda Ospedaliero-Universitaria Pisana, S. Chiara Hospital Departments of †Surgical, Medical, Molecular Pathology and Critical Area ‡Translational Research and of Medical and Surgical New Technologies §Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.
authors.forename: Clara
authors.initials: C
authors.lastname: Ugolini
authors.forename: Nicla
authors.initials: N
authors.lastname: Borrelli
authors.forename: Cristina
authors.initials: C
authors.lastname: Niccoli
authors.forename: Rossella
authors.initials: R
authors.lastname: Elisei
authors.forename: David
authors.initials: D
authors.lastname: Viola
authors.forename: Paolo
authors.initials: P
authors.lastname: Vitti
authors.forename: Paolo
authors.initials: P
authors.lastname: Miccoli
authors.forename: Fulvio
authors.initials: F
authors.lastname: Basolo
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism*; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010750:Phosphoproteins / Q000378:metabolism*; D011379:Prognosis; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics; D013964:Thyroid Neoplasms / Q000378:metabolism / Q000473:pathology*; D014157:Transcription Factors; D000091102:YAP-Signaling Proteins
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D010750:Phosphoproteins; D014157:Transcription Factors; D000091102:YAP-Signaling Proteins; C088374:YAP1 protein, human; D048493:Proto-Oncogene Proteins B-raf