Table 2.

Methods of testing for HPV in cancer patients.

Test	Comments
p16 IHC	commonly performed in clinical labs, high correlation with outcome, but may be elevated in HPV-negative cases
ISH	highly specific and can be performed on paraffin embedded samples, but low sensitivity for tumors with low numbers of copies of the HPV genome
PCR	highly specific and fast turnaround time but environmental contamination can lead to false positive results
RT-PCR	sensitive and specific because it detects actively HPV infection, but requires intact RNA so better results from fresh or frozen tissue than from paraffin-embedded tissue
serology	easy to perform, but no direct relationship to viral-associated cancers

IHC, immunohistochemistry; ISH, in situ hybridization; PCR, polymerase chain reaction; RT-PCR, reverse transcripase polymerase chain reaction