HPV-Driven Head and Neck Squamous Cell Carcinoma in a Developing Nation

Overview

This study assessed the prevalence and characteristics of HPV-driven head and neck squamous cell carcinoma (HNSCC) in Malaysia using RNA in situ hybridization (RNAISH) to detect transcriptionally active high-risk HPV. It highlights the importance of molecular confirmation of HPV status beyond p16INK4a immunohistochemistry to accurately identify HPV-driven tumors and inform prognosis.

Background

Head and neck squamous cell carcinomas (HNSCC) are a heterogeneous group of cancers affecting various subsites such as the oropharynx, nasopharynx, oral cavity, larynx, and hypopharynx. HPV is increasingly recognized as a causative factor, especially in oropharyngeal squamous cell carcinoma (OPSCC), contributing to improved survival outcomes. While most epidemiological data on HPV-driven HNSCC originate from Western countries, data from Asian populations, including Malaysia, remain scarce. Accurate HPV status determination requires molecular methods like E6/E7 mRNA detection, as p16INK4a IHC alone may yield false positives, particularly in regions with low HPV prevalence.

Data Highlights

The study was a cross-sectional multicenter analysis of Malaysian patients aged ≥18 years diagnosed with primary HNSCC from 2016 to 2020. HPV status was determined using RNAISH on formalin-fixed paraffin-embedded tissue, considered the clinical gold standard for detecting transcriptionally active high-risk HPV. Additional data collected included demographics, tobacco and alcohol use, tumor characteristics, and survival status through 2022. Epstein-Barr virus status was recorded for nasopharyngeal carcinoma samples where available.

Key Findings

• HPV-driven HNSCC was defined by positive RNAISH results, distinguishing it from HPV-associated tumors identified by p16INK4a IHC alone.
• p16INK4a IHC, while sensitive, has a false positive rate up to 20%, especially in regions with low HPV prevalence, underscoring the need for confirmatory molecular testing.
• Combining p16INK4a IHC with HPV DNA or E6/E7 mRNA detection improves prognostic accuracy, with discordant cases showing intermediate survival outcomes.
• RNAISH detection of E6/E7 mRNA in FFPE tissue is nearly equivalent to qRT-PCR in fresh tissue, providing a reliable method for clinical HPV status determination.
• The study fills a knowledge gap by providing prevalence and genotype data of HPV-driven HNSCC in Malaysia, informing public health policies.

Clinical Implications

Clinicians should incorporate molecular testing such as RNAISH for E6/E7 mRNA to accurately identify HPV-driven HNSCC, as reliance on p16INK4a IHC alone may misclassify tumors and affect prognosis and treatment decisions. Understanding the local prevalence and HPV genotypes involved can guide targeted prevention strategies, including vaccination and screening programs tailored to the regional epidemiology.

Conclusion

This study establishes the prevalence of truly HPV-driven HNSCC in a Malaysian cohort using RNAISH, emphasizing the necessity of molecular confirmation for accurate diagnosis and prognostication. These findings support the integration of advanced HPV testing methods in clinical practice and public health planning in diverse developing nations.

References

1. Global Cancer Statistics 2018 -- HPV-Attributable Cancers
2. Head and Neck Cancer Subsites and Epidemiology
3. HPV and Oropharyngeal Squamous Cell Carcinoma
4. AJCC Staging for HPV-Driven OPSCC
5. HPV Epidemiology in Malaysia
6. p16INK4a IHC as a Surrogate Marker for HPV
7. False Positivity of p16INK4a IHC and Geographic Variation
8. Clinical Importance of Combined HPV Testing
9. E6/E7 mRNA Detection by RNAISH vs qRT-PCR