Risk of Pathologic Extranodal Extension and Other Adverse Features After Transoral Robotic Surgery in Patients With HPV-Positive Oropharynx Cancer

Importance Understanding patient-specific risk of adverse histopathologic findings after primary surgery for human papillomavirus (HPV)-positive oropharynx squamous cell carcinoma (OPSCC) may help guide patient consultations. Objective To determine the likelihood of adverse histopathologic features that may indicate adjuvant radiotherapy or chemoradiotherapy after primary surgery for HPV-positive OPSCC according to 2021 National Comprehensive Cancer Network guidelines. Design, Setting, and Participants This retrospective cohort study was performed at a single academic tertiary care center. Of 258 patients who underwent transoral robotic surgery (TORS) from March 1, 2012, to March 1, 2021, 136 consecutive, treatment-naive patients with HPV-positive OPSCC without obvious clinical extranodal extension (ENE) who underwent definitive TORS and neck dissection were included in the analysis. Indications for surgical treatment included non–deeply infiltrative oropharynx tumors, minimal soft palate involvement, and low suspicion for pathologic ENE. Exposures Primary site TORS with neck dissection. Main Outcomes and Measures The primary outcomes were the adverse histopathologic features of pathologic ENE and positive surgical margins (PSM) that are indications for possible adjuvant chemoradiotherapy. Outcomes were compared among varying American Joint Committee on Cancer 7th edition (AJCC-7) T and N categories and patient clinical characteristics. Results Of the 136 patients included in the analysis (113 men [83.1%]; median age, 63 [interquartile range, 55-70] years), 109 (80.1%) had at least 1 indication for possible adjuvant radiotherapy. Twenty-seven patients (19.9%) had pathologic ENE and 10 (7.3%) had PSM. Thirty-four patients (25.0%) had pathologic ENE and/or PSM, whereas 3 (2.2%) had both. Age, smoking history, history of alcohol consumption, and clinical T category were not associated with pathologic ENE, PSM, lymphovascular invasion, perineural invasion, or pN2 category or greater. The proportion of pathologic ENE varied by clinical N category: 0 of 16 for cN0, 8 of 48 (16.7%) for cN1, 3 of 23 (13.0%) for cN2a, and 16 of 45 (35.6%) for cN2b. Compared with patients with cN1-cN2a disease, patients with cN2b disease had higher odds of pathologic ENE (odds ratio, 3.01; 95% CI, 1.14-8.10). Clinical and pathologic N category were concordant in 77 patients (56.6%), whereas 42 (30.9%) were upstaged and 17 (12.5%) were downstaged. Conclusions and Relevance In this cohort study, approximately one-quarter of carefully selected patients with HPV-positive OPSCC without obvious clinical ENE undergoing primary surgery had pathologic ENE and/or PSM. Patients with AJCC-7 cT0-cT2 cN0-cN2b disease, especially cN0-cN2a, without signs of clinical ENE may represent appropriate candidates for primary surgery when avoidance of adjuvant chemotherapy and/or reduction of adjuvant radiotherapy dose/extent are the goals.