Muscle invasion in oropharyngeal carcinoma undergoing transoral robotic surgery.

Abstract

Pathologic features of oropharyngeal squamous cell carcinoma (OPSCC) treated with trans-oral robotic surgery predict prognosis and adjuvant therapy. We hypothesized that pathologic muscle invasion (pMI) is associated with poor pathological markers. Retrospective review of surgically treated OPSCC to identify pMI and its association with poor pathologic markers. pMI was present in 12/37 patients, and compared to non-pMI, was associated with higher rates of lymphovascular invasion (75% vs. 36%, p = 0.03), perineural invasion (16.7% vs. 0%, p = 0.04), extranodal extension (66.7% vs. 20%, p < 0.01), and tumor stage (8.3% vs. 48% pT1, 75% vs. 52% pT2 and 16.7% vs. 0% pT3). pMI was associated with having a positive margin on main specimen (41.7% vs. 12%, p = 0.04) but not after considering additional margins. Muscle invasion was associated with higher pathologic tumor staging, poor pathologic factors, and higher rates of positive margin on main specimen.