AJCC-8ed nodal staging does not predict outcomes in surgically managed HPV-associated oropharyngeal cancer.

OBJECTIVE: To assess the pathological outcomes of surgically-managed human papillomavirus (HPV) positive oropharyngeal squamous cell carcinoma (OPSCC) using the 8th Edition of the American Joint Committee on Cancer Staging Manual (AJCC-8ed). MATERIALS AND METHODS: A retrospective review was conducted of 156 patients with previously untreated OPSCC who underwent primary TORS between March 2010 and February 2015 to evaluate the impact of the new AJCC-8ed pathologic staging system. Only patients who had complete pathologic staging with neck dissection and at least 2 years of follow-up records or disease recurrence within 2 years were included for analysis. RESULTS AND CONCLUSIONS: Of the 156 patients, 116 patients had neck dissections and adequate follow-up data. There were 10 total recurrences, including 2 regional recurrences and 1 local recurrence. Lymph node size, number of positive lymph nodes, and presence of any positive nodes were not associated with recurrence for HPV-positive patients. The presence of extranodal extension approached significance. Pathologic N-stage was not predictive of recurrence under the AJCC-7ed or the AJCC-8ed systems. Cancer staging under the AJCC-8ed, but not the AJCC-7ed system was significantly associated with recurrence. In conclusion, pathologic node status as defined in the AJCC-8ed pathologic staging system does not appear to drive prognosis for surgically managed patients. While the new AJCC-8ed staging is an improvement in prognostication, the use of T-stage alone is still a better predictor of recurrence. TORS with adjuvant therapy determined by pathologic findings provides excellent locoregional control for HPV-positive OPSCC.