Relationship of HPV16 E6 seropositivity with circulating tumor tissue modified HPV16 DNA before head and neck cancer diagnosis

Current and Emerging Diagnostic, Prognostic, and Predictive Biomarkers in Head and Neck Cancer

Head and neck cancers (HNC) are a biologically diverse set of cancers that are responsible for over 660,000 new diagnoses each year. Current therapies for HNC require a comprehensive, multimodal approach encompassing resection, radiation therapy, and systemic therapy. With an increased understanding of the mechanisms behind HNC, there has been growing interest in more accurate prognostic indicators of disease, effective post-treatment surveillance, and individualized treatments. This chapter will highlight the commonly used and studied biomarkers in head and neck squamous cell carcinoma.

Blood-based screening for HPV-associated cancers

Background

HPV-associated oropharyngeal cancer (HPV+OPSCC) is the most common HPV-associated cancer in the United States yet unlike cervical cancer lacks a screening test. HPV+OPSCCs are presumed to start developing 10-15 years prior to clinical diagnosis. Circulating tumor HPV DNA (ctHPVDNA) is a sensitive and specific biomarker for HPV+OPSCC. Taken together, blood-based screening for HPV+OPSCC may be feasible years prior to diagnosis.

Methods

We developed an HPV whole genome sequencing assay, HPV-DeepSeek, with 99% sensitivity and specificity at clinical diagnosis. 28 plasma samples from HPV+OPSCC patients collected 1.3-10.8 years prior to diagnosis along with 1:1 age and gender-matched controls were run on HPV-DeepSeek and an HPV serology assay.

Results

22/28 (79%) of cases and 0/28 controls screened positive for HPV+OPSCC with 100% detection within four years of diagnosis and a maximum lead time of 7.8 years. We next applied a machine learning model classifying 27/28 cases (96%) with 100% detection within 10 years. Plasma-based PIK3CA gene mutations, viral genome integration events and HPV serology were used to orthogonally validate cancer detection with 68% (19/28) of the cohort having multiple cancer signals detected. Molecular fingerprinting of HPV genomes was performed across patients demonstrating that each viral genome was unique, ruling out contamination. In patients with tumor blocks from diagnosis (15/28), molecular fingerprinting was performed within patients confirming the same viral genome across time.

Conclusions

We demonstrate accurate blood-based detection of HPV-associated cancers with lead times up to 10 years before clinical cancer diagnosis and in doing so, highlight the enormous potential of ctDNA-based cancer screening.

Detection of serum biomarkers of HPV-16 driven oropharynx and oral cavity cancer in Brazil

BACKGROUND

HPV-16 driven oropharynx/oral cavity squamous cell carcinomas prevalence varies globally. We evaluated the presence of HPV-16 ctDNA and HPV-16 E6 antibodies in samples obtained from participants treated at the Instituto do Cancer do Estado de Sao Paulo, ICESP, and from whom tumoral HPV DNA, HPV-16 E6*I mRNA, and p16INK4a status was also accessed.

METHODS

HPV was genotyped by PCR-hybridization. All HPV DNA positive and ∼10 % HPV DNA negative cases underwent p16INK4a immunohistochemistry and E6*I RNA testing using a multiplex bead based protocol. HPV-16 ctDNA and anti-E6 antibodies were assessed by ddPCR (digital droplet PCR) and multiplex serology, respectively.

RESULTS

The prevalence of HPV-16 in oropharynx carcinoma (OPC) cases was low (8.7 %) when considering solely HPV-16 DNA detection, and even lower (5.2 %) when taken into consideration the concomitant detection of HPV-16 E6*I RNA and/or p16INK4 (HPV-16 attributable fraction - AF). None of the oral cavity cancer (OCC) cases were detected with HPV-16 DNA. HPV-16 ctDNA was more commonly detected than HPV-16 E6 antibodies (29.8 % versus 10.6 %). Both serum biomarkers attained 100 % sensitivity of detecting HPV-16 AF OPC, however the specificity of the HPV-16 anti-E6 biomarker was higher compared to ctDNA (93.2 % versus 75.0 %). Finally, when both HPV-16 ctDNA and anti-E6 biomarkers were considered together, the sensitivity and specificity for HPV-16 OPC detection was 100 % and about 70 %, respectively, independently of analyzing HPV-16 DNA positive or HPV-16 AF tumors.

CONCLUSIONS

Our findings corroborate that serum biomarkers are highly sensitive and specific biomarkers for detection of HPV-associated OPC.