>> P-563: A comparison of clinically utilized HPV detection methods in head and neck squamous cell carcinoma (HNSCC)
19:00 PM - 19:00 PM
Nicolas F. Schlecht1,8, Magaret Brandwein-Gensler2, Gerard Nuovo3, Maomi Li4, Richard Smith5, Robert Burk1,6, Michael Prystowsky7.
1Department of Epidemiology & Population Health, Albert Einstein College of Medicine, NY, USA; 2Department of Pathology, University of Alabama Birmingham, AL, USA; 3Department of Pathology, Ohio State University College of Medicine, OH, USA; 4Genzyme, NY, USA; 5Department of Otorhinolaryngology-Head and Neck Surgery, Montefiore Medical Center, NY, USA; 6Department of Pediatrics (Genetics), Albert Einstein College of Medicine, NY, USA; 7Department of Pathology, Albert Einstein College of Medicine, NY, USA; 8Department of Medicine (Oncology), Albert Einstein College of Medicine, NY, USA.
Background: Detection of HPV in HNSCC has therapeutic implications. In-situ hybridization (ISH) with HPV DNA probes and immuno-histochemistry (IHC) for p16 are used by clinical pathologists. IHC is readily available and easily performed, whereas ISH is less readily available. We compared the sensitivity and specificity of three popular commercial tests for HPV detection in HNSCC tumors compared to a "gold standard" HPV PCR assay.
Methods: A hundred-and-seven prospectively collected tumor specimens were tested for HPV DNA by PCR, HPV ISH and p16 IHC. Tissue microarrays (TMA) were constructed from formalin fixed tumor tissue and tested for HPV DNA by ISH with two different probe sets: INFORM HPV-III Fam16(B) probe for 12 high-risk types (Ventana, AZ) and an HPV16/18-specific probe (Dako, CA). p16INK4 expression was tested for using a BD Pharmingen IHC antibody (BD Biosciences, CA). Stained TMA were then scored at commercial laboratories. HPV DNA was detected by MY09/11 PCR and dot blot in a research laboratory. Test performance was assessed by ROC analysis.
Results: HPV16/18 only and "all high-risk types" were detected by MY-PCR in 27% and 28%, respectively. Compared to MY-PCR, the sensitivity and specificity of HPV16/18 DNA detection using Dako was 17.2% (95%CI:5.9%-35.8%) and 100% (95%CI:95.4%-100%), respectively. Corresponding test results for high-risk HPV by Ventana were 53.3% (95%CI:34.3%-71.7%) and 67.5% (95%CI:55.9%-77.8%), respectively. Compared to MY-PCR for high-risk HPV, p16 IHC performed better than Dako (p=0.009) and Ventana (p=0.149), with a sensitivity of 46.7% (95%CI:28.3%-65.7%) and specificity of 93.5% (95%CI: 85.5%-97.9%).
Conclusions: Compared to gold standard MY-PCR, HPV DNA detection by Dako ISH was statistically less accurate for HNSCC TMA than p16 IHC. Test sensitivity for Ventana ISH and p16 IHC was comparable but low. Further clinical testing is warranted before any of these assays should be recommended as a first line test for HPV detection.
