Absence of disruptive TP53 mutations in high-risk human papillomavirus-driven neck squamous cell carcinoma of unknown primary.

Background: To enforce the evidence for causality between high-risk human papillomavirus (hrHPV) infections and neck squamous cell carcinoma from unknown primary (NSCCUP) and provide biological basis for treatment de-intensification, we searched for TP53 mutations in association with HPV status.

Methods: TP53 mutations were searched for by amplification of exons 4 to 10.

Results: Of the 70 NSCCUP, 27 (39%) harbored HPV infection. TP53 sequencing resulted in the identification of 19 patients harboring single mutations including 16 disruptive alterations (84%). The association of TP53 mutations and HPV could be evaluated in 48 NSCCUP including those with disruptive mutation in any exon (n = 16) and those without mutations but with complete sequence of exons 4 to 9 (n = 32): no disruptive mutations were found in the 17 HPV-driven NSCCUP but in 16 of the 31 non-HPV-driven NSCCUP (P = .0002).

Conclusion: In a fraction of cases, NSCCUP is an HPV-driven entity harboring wild-type TP53 gene or nondisruptive TP53 mutations. HPV-driven NSCCUP might benefit from treatment de-intensification.