Sensitivity and specificity of antibodies against HPV16 E6 and other early proteins for the detection of HPV16-driven oropharyngeal squamous cell carcinoma.

Dana Holzinger,Lea Schroeder,Daniela Höfler,Lorena Baboci,Michael Pawlita,Andreas Boehm,Gerhard Dyckhoff,Annarosa Del Mistro,Paolo Boscolo‐Rizzo,Tim Waterboer,Angelika Michel,Gunnar Wichmann,Andreas Dietz,Manuel Wiesenfarth,Franz X Bosch,Christel Herold‐Mende

doi:10.1002/ijc.30697

Abstract

To determine the sensitivity and specificity of HPV16 serology as diagnostic marker for HPV16-driven oropharyngeal squamous cell carcinoma (OPSCC), 214 HNSCC patients from Germany and Italy with fresh-frozen tumor tissues and sera collected before treatment were included in this study. Hundred and twenty cancer cases were from the oropharynx and 94 were from head and neck cancer regions outside the oropharynx (45 oral cavity, 12 hypopharynx and 35 larynx). Serum antibodies to early (E1, E2, E6 and E7) and late (L1) HPV16 proteins were analyzed by multiplex serology and were compared to tumor HPV RNA status as the gold standard. A tumor was defined as HPV-driven in the presence of HPV16 DNA and HPV16 transformation-specific RNA transcript patterns (E6*I, E1∧ E4 and E1C). Of 120 OPSCC, 66 (55%) were HPV16-driven. HPV16 E6 seropositivity was the best predictor of HPV16-driven OPSCC (diagnostic accuracy 97% [95%CI 92-99%], Cohen's kappa 0.93 [95%CI 0.8-1.0]). Of the 66 HPV-driven OPSCC, 63 were HPV16 E6 seropositive, compared to only one (1.8%) among the 54 non-HPV-driven OPSCC, resulting in a sensitivity of 96% (95%CI 88-98) and a specificity of 98% (95%CI 90-100). Of 94 HNSCC outside the oropharynx, six (6%) were HPV16-driven. In these patients, HPV16 E6 seropositivity had lower sensitivity (50%, 95%CI 19-81), but was highly specific (100%, 95%CI 96-100). In conclusion, HPV16 E6 seropositivity appears to be a highly reliable diagnostic marker for HPV16-driven OPSCC with very high sensitivity and specificity, but might be less sensitive for HPV16-driven HNSCC outside the oropharynx.

Highlights

In this study, we determined the predictive accuracy of HPV16 antibodies to the oncoproteins E6 and E7, the regulatory proteins E1 and E2 and the major capsid protein L1 in serum of head and neck squamous cell carcinomas (HNSCC) patients as diagnostic markers for HPV16driven oropharyngeal squamous cell carcinomas (OPSCC) and HNSCC outside the oropharynx
This is the first study that has comprehensively analyzed the potential of antibodies to HPV16 E proteins as a diagnostic marker for HNSCC with molecularly defined Human papillomavirus (HPV) status including RNA analyses as gold-standard
The antibody patterns observed in high frequency among the HPV-driven OPSCC patients in this study have been seen in our previous studies in OPSCC patients with undefined HPV status, albeit with lower prevalence.[20,21,24,41]

Summary

Introduction

Human papillomavirus (HPV) infection is associated with a subset of oropharyngeal squamous cell carcinomas (OPSCC),[1,2,3] and a small proportion of head and neck squamous cell carcinomas (HNSCC) outside the oropharynx.[4,5]HPV-driven OPSCC are regarded as distinct tumor entity and are characterized by (i) at least one HPV genome copy per tumor cell,[6,7,8] (ii) active viral oncogene expression[6,7,9,10,11,12,13] affecting the levels of cellular proteins regulating cell cycle (e.g., high levels of p16INK4a and low levels of pRb) as well as apoptosis (low levels of p53) and (iii) better patient survival.[9,11,14] In contrast, HPV DNA-positive but non-HPV-drivenOPSCC harbor HPV DNA only in low copy numbers with absent or low-level viral transcription, have no apparent effect on cellular surrogate markers (low levels of p16INK4a and high levels of pRb) and patient survival is similar to that of patients with HPV-negative tumors.[1,6,11] documenting biologically active HPV infections rather than mereInt. HPV-driven OPSCC are regarded as distinct tumor entity and are characterized by (i) at least one HPV genome copy per tumor cell,[6,7,8] (ii) active viral oncogene expression[6,7,9,10,11,12,13] affecting the levels of cellular proteins regulating cell cycle (e.g., high levels of p16INK4a and low levels of pRb) as well as apoptosis (low levels of p53) and (iii) better patient survival.[9,11,14] In contrast, HPV DNA-positive but non-HPV-driven.

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Methods

Conclusion