Transoral robotic surgery for human papillomavirus-associated oropharynx squamous cell carcinoma: Recurrence and survival in the Veterans Affairs health system.
Authors: Abhishek Kumar, Daniel R. Cherry, Rohith S. Voora, Farhoud Faraji, Patrick Travis Courtney, Andrey Finegersh, Theresa Guo, Ezra E.W. Cohen, Joseph A. Califano, Loren K. Mell, Brent S. Rose, Ryan K. Orosco
Journal: Journal of Clinical Oncology (2021)

6054 Background: Most transoral robotic surgery (TORS) literature comes from single and multi-institutional studies at tertiary-care academic intuitions. Long-term outcomes for patients with HPV-mediated oropharyngeal squamous cell carcinoma (HPV-OPSCC) treated with upfront TORS in other hospital settings across the United States are largely unknown. We present long-term recurrence and survival outcomes from a novel Veterans Health Administration (VHA) longitudinal dataset that includes patient-level data. Methods: Retrospective analysis of national VHA patients with p16-positive OPSCC diagnosed between January 2010 and December 2016, treated with TORS primary tumor resection with neck dissection. Outcome measures included: Cancer-specific survival (CSS), progression free survival (PFS), overall survival (OS), recurrence, extranodal extension (ENE), positive surgical margin (PSM), and adjuvant therapy regimen. Results: One hundred sixty-one patients were included of whom 29 (18%) were low-risk [0-1 metastatic lymph nodes, negative margins]; 45 (28%) intermediate-risk [close surgical margins, 2 to 4 metastatic nodes, LVI or PNI, pathologic T3 or T4 tumor]; and 87 (54%) high-risk [PSM, ENE, and/or ≥ 5 metastatic nodes]. ENE was present in 41% of cases and 24% of cases had positive surgical margins. Median follow-up was 5.6 years (95% CI 3.0-9.3). The 5-year CSS rates for low, intermediate, and high-risk groups were: 100%, 90.0% (95% CI 75.4-96.1%), and 88.7% (78.3-94.2%). On univariable analysis, pathologic factors associated with inferior CSS were: pT3-T4 tumor category (HR 3.81, 95% CI 1.31-11; p = 0.01), presence of more than four metastatic lymph nodes (HR 3.41, 95% CI 1.20-11; p = 0.02), and ENE (HR 3.53, 95% CI 1.06-12; p = 0.04). Close or PSM were not associated with CSS (HR 0.67, 95% CI 0.21 – 2.14; p = 0.50). In the low-risk group, 48% avoided adjuvant therapy and although there were five recurrences, none died from cancer. The intermediate-risk group was treated with adjuvant radiation in 64% of cases, and chemoradiation in 29% of cases; and there were five locoregional recurrences and three distant recurrences. Adjuvant chemoradiation was used in 68% of high-risk cases. Of the seven total patients with distant recurrences, six died of their disease. Conclusions: Our findings in this national cohort of Veterans with HPV-OPSCC demonstrate that TORS followed by adjuvant therapy yields favorable survival outcomes. Tumor-category, ENE, and more than four nodal metastases were the strongest adverse features in our data, and surgical margins did not have a significant impact on survival. Further investigations with large cohorts and prospective clinical trials are needed to elucidate the true oncologic implications of high-risk features and to identify patients best suited for de-intensified treatment.