[Correspondence] Misclassification of p16-positive, HPV-negative patients biases de-escalation trials – Authors' reply

We appreciate the important points raised by Jessica T Lovett and colleagues regarding p16 immunohistochemistry as a surrogate for HPV status in oropharyngeal squamous cell carcinoma in de-escalation studies such as MC1675.1 As they noted, the prognostic implications of p16 and HPV discordance have been previously analysed, such as in a multinational study by Mehanna and colleagues.2 Patients who were p16-positive and HPV-negative had an increased rate of cancer recurrence (hazard ratio 1·92, 95% CI 1·42–2·60).