Evaluation of an HPV16-L1 antibody rapid test for oropharyngeal cancer diagnosis: diagnostic accuracy and challenges in real-world settings

Background: Diagnostic assays have been introduced to diagnose human papillomavirus (HPV)-driven oropharyngeal cancer (HPV-OPC), including those identifying HPV16-L1 antibodies. This study aims to evaluate the diagnostic accuracy of an HPV16-L1 antibody rapid test for HPV-OPC, and its performance in individuals likely to have HPV16-L1 antibodies from causes other than HPV-OPC. Methods: Serum samples (n = 235) from three study populations were tested using a CE-certified serological HPV16-L1 antibody rapid test (Prevo-Check®) at the German National Reference Center for Papillomaviruses. Laboratory personnel were blinded to participant characteristics and followed the manufacturer's instructions. The three study populations consisted of: (1) patients with HPV16-positive or -negative OPC (n = 83), (2) bivalent (HPV16/18) vaccine recipients (n = 50), with paired baseline and one-month post-third-dose serum samples, and (3) naturally HPV16 infected young adults (n = 26), with paired serum samples before and after HPV16 seroconversion. Findings: In the study population with patients with OPC, the sensitivity of the HPV16-L1 antibody rapid test to detect HPV-OPC was 25.0% (95% CI: 13.6, 39.6), and its specificity was 97.1% (95% CI: 85.1, 99.9). The positive predictive value was 92.3% (95% CI: 64.0, 99.8) and negative predictive value 48.6% (95% CI: 36.4, 60.8). In the other study populations, the test was negative for all pre-vaccination samples, and all samples collected before incident natural HPV16 infection. Nearly all post-vaccination samples (98.0%), and one-third of the samples after natural HPV16 infection (34.6%) tested positive in the HPV16-L1 antibody rapid test. Interpretation: The HPV16-L1 antibody test has low diagnostic accuracy and cannot reliably distinguish different sources of HPV16-L1 antibodies. Therefore, this type of assays is not suitable for screening and detection of HPV16-driven OPC. Funding: This study is supported by the Ministry of Research, Technology and Space (BMFTR) core bvfunding provided to DKFZ. The NRC for Papilloma- and Polyomaviruses is supported by the Ministry of Health (BMG, grant no. 1369-401).