Prognostic significance of p16 protein levels in oropharyngeal squamous cell cancer.
OBJECTIVE
Functional inactivation of p16 is an early and frequent event in head and neck squamous cell cancers. In this study, we sought to determine whether p16 expression is of prognostic importance in oropharyngeal squamous cell carcinoma.


METHODS
p16 protein expression was evaluated by immunohistochemistry in a tissue microarray composed of 123 oropharyngeal squamous cell cancers with a mean patient follow-up time of 33 months.


RESULTS
p16 overexpression was associated with more advanced Tumor-Node-Metastasis stage and higher histologic grade. Despite this association with unfavorable features, p16 overexpression was associated with decreased 5-year local recurrence rates (11 versus 53%) and increased 5-year disease-free survival (62 versus 19%) and overall survival (60 versus 21%). In multivariate analysis, p16 expression status remained an independent prognostic factor for local recurrence, disease-free survival, and overall survival.


CONCLUSIONS
In patients with oropharyngeal squamous cell carcinoma, overexpression of p16 as determined by immunohistochemistry is associated with significantly improved prognosis and lower local recurrence rates.
Weinberger
Paul M
PM
Department of Medical Oncology, Yale University School of Medicine, New Haven, Connecticut, USA.
Yu
Z
Z
Haffty
B G
BG
Kowalski
D
D
Harigopal
M
M
Sasaki
C
C
Rimm
D L
DL
Psyrri
A
A
D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis / Q000378:metabolism*; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000378:metabolism*; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008207:Lymphatic Metastasis / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000378:metabolism; D009959:Oropharyngeal Neoplasms / Q000175:diagnosis / Q000378:metabolism*; D011379:Prognosis; D015996:Survival Rate; D014062:Tongue Neoplasms / Q000175:diagnosis / Q000378:metabolism; D014067:Tonsillar Neoplasms / Q000175:diagnosis / Q000378:metabolism
D019941:Cyclin-Dependent Kinase Inhibitor p16