Probes for P16

Detection of human papilloma virus (HPV)-related head and neck squamous cell carcinoma (HNSCC) is important, as HPV-associated HNSCCs respond better to therapy. The RNAscope HPV-test is a novel RNA in situ hybridization (ISH) technique which strongly stains transcripts of E6 and E7 mRNA in formalin-fixed, paraffin-embedded tissue, with the potential to replace the indirect immunohistochemical (IHC) marker for p16 protein. A direct clinical comparison between p16 IHC and an automated RNA ISH using 18 probes has not been established. Samples from 27 formalin-fixed, paraffin-embedded HNSCC cases from the Emory University Hospital archives were stained using 18 individual RNA ISH probes for high-risk HPV (RNAscope 2.5 LS Probe ) on a Leica autostainer (Buffalo Grove, IL) and were compared with p16 IHC. Two pathologists reviewed and reached a consensus on all interpretations. The RNAscope technique was positive in 89% (24/27) and the p16 IHC was positive in 78% (21/27). The RNAscope was negative in 11.1% of samples (3/27) and the p16 IHC-negative in 22.2% (6/27). The RNA ISH detected 100% of the p16-positive IHC-stained slides and had a concordance of 88.9% (24/27). This easy to interpret automated staining method for 18 high-risk HPV genotypes is a feasible replacement for the indirect p16 IHC method.

HPV-related multiphenotypic sinonasal carcinoma (HMSC) is associated with high-risk human papillomavirus (HR-HPV) infection. Using HR-HPV mRNA in situ hybridization (ISH), we reported six new HMSC cases and compared their histopathology with that of sinonasal adenoid cystic carcinoma (ACC). Using p16 immunohistochemistry (IHC) and HR-HPV ISH, we retrospectively identified six HMSC cases. All HMSC cases were positive for HR-HPV mRNA ISH and p16 IHC. Two HMSC cases had overlying atypical squamous epithelium and one also had invasive squamous cell carcinoma (SCC). All HMSC were SOX10-positive whereas the overlying atypical squamous epithelium and the SCC were SOX10-negative. One atypical HMSC-like case was also identified which was positive for HR-HPV mRNA ISH, HR-HPV DNA ISH, SOX10 IHC, but negative for p16 IHC. This study showed that HR-HPV mRNA ISH was a useful tool to diagnose HMSC and had stronger signals than HR-HPV DNA ISH. HR-HPV E6/E7 mRNA could be identified in the overlying atypical squamous epithelium as well as the invasive SCC. A combination of p16 and SOX10 IHC will be a useful screening panel for HMSC followed by confirmatory HR-HPV mRNA ISH test.

The oral cavity and oropharynx have historically been viewed as a single anatomic compartment of the head and neck. The practice of combining the oral cavity and oropharynx has recently been revised, largely owing to the observation that human papillomavirus (HPV)-related carcinogenesis has a strong predilection for the oropharynx but not the oral cavity. The purpose of this study was to determine whether HPV is evenly distributed across squamous cell carcinomas of the oropharynx including those sites that do not harbor tonsillar tissues such as the soft palate. A search of the medical records of the Johns Hopkins Hospital identified 32 primary squamous cell carcinomas of the soft palate (n=31) and posterior pharyngeal wall (n=1). All were evaluated with p16 immunohistochemistry and high-risk HPV in situ hybridization (ISH) (29 by RNA ISH and 3 by DNA ISH). For comparison, we also reviewed the medical records to obtain the HPV status of patients who had undergone HPV testing of primary tonsillar carcinomas over the same time interval as part of their clinical care. High-risk HPV as detected by ISH was present in just 1 (3.1%) of the 32 oropharyngeal squamous cell carcinomas, including 1 of 2 p16-positive carcinomas. The difference in HPV detection rates between tonsillar and nontonsillar sites was significant (1/32, 3.1% vs. 917/997, 92%; P<0.0001). HPV is not frequently detected in squamous cell carcinomas arising from nontonsillar regions of the oropharynx. Indeed, squamous cell carcinomas of the soft palate more closely resemble those arising in the oral cavity than those arising in areas of the oropharynx harboring tonsillar tissue. This finding not only further sharpens our understanding of site-specific targeting by HPV, but may have practical implications regarding HPV testing and even the way the oral vault is oncologically compartmentalized to partition HPV-positive from HPV-negative cancers.

Abstract

Importance  
High-risk human papillomavirus (HPV) has been associated with Barrett dysplasia and esophageal adenocarcinoma. Nevertheless, the prognostic significance of esophageal tumor HPV status is unknown.

Objective  
To determine the association between HPV infection and related biomarkers in high-grade dysplasia or esophageal adenocarcinoma and survival.

Design, Setting, and Participants  
Retrospective case-control study. The hypothesis was that HPV-associated esophageal tumors would show a favorable prognosis (as in viral-positive head and neck cancers). Pretreatment biopsies were used for HPV DNA determination via polymerase chain reaction, in situ hybridization for E6 and E7 messenger RNA (mRNA), and immunohistochemistry for the proteins p16INK4A and p53. Sequencing of TP53 was also undertaken. The study took place at secondary and tertiary referral centers, with 151 patients assessed for eligibility and 9 excluded. The study period was from December 1, 2002, to November 28, 2017.

Main Outcomes and Measures  
Disease-free survival (DFS) and overall survival (OS).

Results  
Among 142 patients with high-grade dysplasia or esophageal adenocarcinoma (126 [88.7%] male; mean [SD] age, 66.0 [12.1] years; 142 [100%] white), 37 were HPV positive and 105 were HPV negative. Patients who were HPV positive mostly had high p16INK4A expression, low p53 expression, and wild-type TP53. There were more Tis, T1, and T2 tumors in HPV-positive patients compared with HPV-negative patients (75.7% vs 54.3%; difference, 21.4%; 95% CI, 4.6%-38.2%; P = .02). Mean DFS was superior in the HPV-positive group (40.3 vs 24.1 months; difference, 16.2 months; 95% CI, 5.7-26.8; P = .003) as was OS (43.7 vs 29.8 months; difference, 13.9 months; 95% CI, 3.6-24.3; P = .009). Recurrence or progression was reduced in the HPV-positive cohort (24.3% vs 58.1%; difference, −33.8%; 95% CI, −50.5% to −17.0%; P < .001) as was distant metastasis (8.1% vs 27.6%; difference, −19.5%; 95% CI, −31.8% to −7.2%; P = .02) and death from esophageal adenocarcinoma (13.5% vs 36.2%; difference, −22.7%; 95% CI, −37.0% to −8.3%; P = .01). Positive results for HPV and transcriptionally active virus were both associated with a superior DFS (hazard ratio [HR], 0.33; 95% CI, 0.16-0.67; P = .002 and HR, 0.44; 95% CI, 0.22-0.88; P = .02, respectively [log-rank test]). Positivity for E6 and E7 mRNA, high p16INK4Aexpression, and low p53 expression were not associated with improved DFS. On multivariate analysis, superior DFS was demonstrated for HPV (HR, 0.39; 95% CI, 0.18-0.85; P = .02), biologically active virus (HR, 0.36; 95% CI, 0.15-0.86; P = .02), E6 and E7 mRNA (HR, 0.36; 95% CI, 0.14-0.96; P = .04), and high p16 expression (HR, 0.49; 95% CI, 0.27-0.89; P = .02).

Conclusions and Relevance  
Barrett high-grade dysplasia and esophageal adenocarcinoma in patients who are positive for HPV are distinct biological entities with a favorable prognosis compared with viral-negative esophageal tumors. Confirmation of these findings in larger cohorts with more advanced disease could present an opportunity for treatment de-escalation in the hope of reducing toxic effects without deleteriously affecting survival.