Comparative prognostic value of HPV16 E6 mRNA compared with in situ hybridization for human oropharyngeal squamous carcinoma.
OBJECTIVE
A significant proportion of oropharyngeal squamous cell carcinomas (OSCC) are associated with the human papilloma virus (HPV), particularly HPV16. The optimal method for HPV determination on archival materials however, remains unclear. We compared a quantitative real-time polymerase chain reaction (qRT-PCR) assay for HPV16 mRNA to a DNA in situ hybridization (ISH) method, and evaluated their significance for overall (OS) and disease-free (DFS) survival.


METHODS
Matched, archival biopsies from 111 patients with OSCC were evaluated for HPV16 using a qRT-PCR for E6 mRNA and ISH for DNA. Immunohistochemistry for p16, p53, and epidermal growth factor receptor were also performed.


RESULTS
HPV16 E6 mRNA was positive in 73 (66%) of 111 samples; ISH was positive in 62 of 106 samples (58%), with 86% concordance. P16 was overexpressed in 72 samples (65%), which was strongly associated with HPV16 status by either method. E6 mRNA presence or p16 overexpression were significantly associated with superior OS; E6 mRNA, HPV16 ISH, or p16 were all significantly associated with DFS. On multivariate analysis adjusted for age, stage, and treatment, positive E6 mRNA was the only independent predictor for superior OS; for DFS, p16 expression or HPV16 status determined by either method was significant.


CONCLUSIONS
The prevalence of HPV16 in OSCC ranges from 58% to 66%, in a recently treated Canadian cohort. Classification of HPV-positivity by HPV16 E6 mRNA, HPV16 ISH or p16 immunohistochemistry (IHC) is associated with improved DFS. However, the latter two assays are technically easier to perform; hence, HPV16 ISH or p16 IHC should become standard evaluations for all patients with OSCC.
Shi
Wei
W
Department of Radiation Oncology, Princess Margaret Hospital/Ontario Cancer Institute, 610 University Ave, Toronto, Ontario, Canada, M5G 2M9.
Kato
Hisayuki
H
Perez-Ordonez
Bayardo
B
Pintilie
Melania
M
Huang
Shaohui
S
Hui
Angela
A
O'Sullivan
Brian
B
Waldron
John
J
Cummings
Bernard
B
Kim
John
J
Ringash
Jolie
J
Dawson
Laura A
LA
Gullane
Patrick
P
Siu
Lillian
L
Gillison
Maura
M
Liu
Fei-Fei
FF
D000328:Adult; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000821:virology*; D019941:Cyclin-Dependent Kinase Inhibitor p16; D018572:Disease-Free Survival; D066246:ErbB Receptors / Q000096:biosynthesis; D005260:Female; D006801:Humans; D017403:In Situ Hybridization; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000096:biosynthesis; D009856:Oncogene Proteins, Viral / Q000096:biosynthesis / Q000235:genetics*; D009959:Oropharyngeal Neoplasms / Q000378:metabolism / Q000821:virology*; D027383:Papillomaviridae / Q000235:genetics* / Q000378:metabolism; D030361:Papillomavirus Infections / Q000378:metabolism / Q000821:virology; D016133:Polymerase Chain Reaction; D011379:Prognosis; D011446:Prospective Studies; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000235:genetics; D012097:Repressor Proteins / Q000096:biosynthesis / Q000235:genetics*; D016896:Treatment Outcome; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis; D055815:Young Adult
C000614131:CDKN2A protein, human; D019941:Cyclin-Dependent Kinase Inhibitor p16; C068651:E6 protein, Human papillomavirus type 16; D009363:Neoplasm Proteins; D009856:Oncogene Proteins, Viral; D012333:RNA, Messenger; D012097:Repressor Proteins; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D066246:ErbB Receptors