The accuracy of clinical neck staging for p16-positive and negative oropharyngeal cancer and its therapeutic implications

Purpose Oropharyngeal squamous cell carcinoma (OPSCC) may be treated with primary surgery or primary (chemo)radiation. While surgery with concurrent neck dissection provides definitive pathological staging of the neck, non-surgical treatment relies on clinical staging for treatment planning. To assess the accuracy of clinical neck staging, we compared clinical to surgical staging after primary surgery in patients with p16-negative and p16-positive OPSCC. Methods Retrospective analysis of clinical, pathological, and oncologic outcome data of patients with OPSCC treated with primary surgery and bilateral neck dissection. Clinical and pathological nodal status were compared for p16-negative and p16-positive patients. Patients with occult metastatic disease were analyzed in detail. Results 95 patients were included . 60.5% of p16-negative patients and 66.6% of p16-positive patients had pathologically confirmed metastatic neck disease. p16-positive patients had improved 24-month recurrence-free survival compared to p16-negative patients at 93.3% vs. 69.6%. Pathological N-status differed from clinical N-status in 36.8% of p16-negative patients vs. 31.6% of p16-positive patients. Occult metastatic disease was more common in p16-negative patients at 18.4% vs. 8.8% for p16-positive patients. Clinical detection sensitivity for extranodal extension was low overall; sensitivity was 27.3% and specificity was 91.6% for p16-negative patients vs. 61.5% and 80.0% for p16-positive patients, respectively. Conclusion Our data show a considerable degree of inaccuracy of clinical neck staging results in all OPSCC patients which needs to be taken into consideration during therapy planning. For p16-positive patients, these findings warrant attention in the context of therapy deintensification to avoid undertreatment.