Transoral Robotic Surgery-Assisted Endoscopy With Primary Site Detection and Treatment in Occult Mucosal Primaries.

Importance: Management of cervical lymph node metastasis without a known primary tumor is a diagnostic and treatment challenge for head and neck oncologists. Identification of the occult mucosal primary tumor minimizes the morbidity of treatment.

Objective: To analyze the role of transoral robotic surgery (TORS) in facilitating the identification of a primary tumor site for patients presenting with squamous cell carcinoma of unknown primary (CUP). In addition, we assessed treatment deintensification by determining the number of patients who did not undergo definitive radiation therapy and chemotherapy.

Design, Setting, and Participants: In this retrospective case series from January 2011 to September 2015, 60 consecutive patients with squamous cell CUP who underwent TORS-assisted endoscopy and ipsilateral neck dissection were included from an academic medical center and studied to study the rate success rate of TORS identifying occult mucosal malignancy.

Main Outcomes and Measures: Success rate of identifying occult mucosal malignancy; usage of radiation therapy and chemotherapy.

Results: Overall, 60 patients (mean [SD] age, 55.5 [8.9] years) were identified; 48 of the 60 patients (80.0%) had a mucosal primary identified during their TORS-assisted endoscopic procedure. The mean (SD) size of the identified mucosal primary lesions was 1.3 (0.1) cm. All mucosal primaries, when found, originated in the oropharynx including the base of tongue in 28 patients (58%), palatine tonsil in 18 patients (38%), and glossotonsillar sulcus in 2 patients (4%). Among patients in this study, 40 (67%) did not receive chemotherapy, and 15 (25%) did not receive radiation therapy.

Conclusions and Relevance: Advances in transoral surgical techniques have helped identify occult oropharyngeal malignancies that traditionally have been treated with comprehensive radiation to the entire pharyngeal axis. We demonstrate the efficacy of a TORS-assisted approach to identify and surgically treat the primary tumor in patients presenting with CUP. In addition, patients managed with the TORS-assisted endoscopic approach benefit from surgical and pathological triage, which in turn results in deintensification of treatment by eliminating the need for chemotherapy in the majority of patients, as well as avoiding radiation therapy in select patients.