title: P16 expression in squamous cell carcinomas of cervix and bladder.
abstract: OBJECTIVE
  p16 is a widely used immunohistochemical marker in gynecologic pathology. Strong and diffuse cytoplasmic and nuclear expression of p16 in squamous cell carcinomas (SCC) of the female genital tract is strongly associated with high-risk human papilloma virus infection and neoplasms of cervical origin. However, p16 can be expressed in other neoplasms and in several normal human tissues. Occasionally, SCCs may involve both uterine cervix and urinary bladder. Accurate identification of the site of origin in such cases has therapeutic and prognostic implications. We investigate the potential value of p16 expression in this distinction.
  
  
  METHODS
  We reviewed 74 SCCs, 38 (51%) from urinary bladder and 36 (49%) from uterine cervix obtained between 2003 and 2008. Of the 38 cases of bladder carcinoma, 21 occurred in females and 17 in males. Immunohistochemical analysis for p16 (DAKO M7247, clone 484, dilution of 1:50) expression was done in all cases using the labeled streptavidin-biotin method.
  
  
  RESULTS
  Strong and diffuse nuclear and cytoplasmic p16 positivity was observed in 45 cases (61%). Of the 38 SCCs of urinary bladder, 14 (37%) expressed p16 (8 males, 6 females). Of the 36 SCCs of uterine cervix, 31 (86%) were positive for p16.
  
  
  CONCLUSIONS
  (1) The majority of SCCs of uterine cervix express p16. (2) More than a third of urinary bladder SCCs express p16. (3) SCCs of urinary bladder express p16 independent of gender. (4) p16 immunohistochemical expression alone cannot be used to discriminate between SCCs arising from uterine cervix versus urinary bladder.
authors.affiliation: Department of Pathology, University of Miami Miller School of Medicine, Health System at Jackson Memorial Hospital, FL 33136, USA.
authors.forename: Maureen
authors.initials: M
authors.lastname: Cioffi-Lavina
authors.forename: Jennifer
authors.initials: J
authors.lastname: Chapman-Fredricks
authors.forename: Carmen
authors.initials: C
authors.lastname: Gomez-Fernandez
authors.forename: Parvin
authors.initials: P
authors.lastname: Ganjei-Azar
authors.forename: Murigesan
authors.initials: M
authors.lastname: Manoharan
authors.forename: Merce
authors.initials: M
authors.lastname: Jorda
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000378:metabolism*; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000235:genetics / Q000378:metabolism*; D003937:Diagnosis, Differential; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D020022:Genetic Predisposition to Disease; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D001749:Urinary Bladder Neoplasms / Q000175:diagnosis / Q000235:genetics / Q000378:metabolism*; D002583:Uterine Cervical Neoplasms / Q000175:diagnosis / Q000235:genetics / Q000378:metabolism*
chemical_list: D019941:Cyclin-Dependent Kinase Inhibitor p16