Human Papillomaviruses 16 and 18 E6 Oncoprotein Detection Test in Primary Oropharyngeal Carcinomas and Metastatic Lymph Nodes: A Cross-Sectional Study.

PURPOSE

Accuracy in the diagnosis of HPV-associated oropharyngeal carcinoma (OPSCC) of a rapid, low-cost lateral flow immunochromatographic assay for detecting E6 oncoprotein of HPV-16 and HPV-18 was previously evaluated in a small pilot study. This cross-sectional study aimed to assess on a large case series the sensitivity and specificity of E6 oncoprotein as a diagnostic marker for HPV-associated carcinogenesis in OPSCC.

METHODS

137 consecutive patients with histologically confirmed OPSCC were enrolled in two hospitals in Northeast Italy. HPV status was determined by PCR for HPV DNA and p16 immunohistochemistry on primary tumor biopsies. An OPSCC was defined as HPV-associated when double positive for high-risk HPV-DNA and p16 overexpression in primary lesion. Cytological samples from primary tumors and metastatic lymph nodes were obtained and tested for HPV16/18 E6 oncoproteins using the lateral flow immunochromatographic assay, which requires between 90 and 120 min to provide a result. Diagnostic performances were calculated as percentage with confidence intervals (CI).

RESULTS

Of the 137 OPSCC cases, 68 (49.6%) were HPV-associated, testing positive for both high-risk HPV-DNA and p16, with HPV16 predominating (82.4%). An average waiting time of 22 days was observed to obtain the results of p16 and HPV-DNA after primary lesions biopsy. In patients with HPV16/18-associated OPSCC, the HPV16/18 E6 oncoprotein was detected in 59 out of 60 cytological samples from the primary lesion (sensitivity: 98.3%; 95% CI: 91.1-100%) and in 45 out of 51 cytological samples from lymph node metastases (sensitivity: 88.2%; 95% CI: 76.1-95.6%). The E6 oncoprotein assay showed a specificity of 100% in both primary tumors and lymph node metastases.

CONCLUSION

The low-cost lateral flow immunochromatographic assay for detecting HPV16/18 E6 oncoproteins confirmed high accuracy for identifying HPV-associated OPSCC, particularly in primary tumors, suggesting its potential as a valuable diagnostic tool in clinical practice. Its rapid diagnostic capability could significantly accelerate the process of treatment decision-making, enhancing the timely management of patients.