Importance: Identification of the primary site in head and neck squamous cell carcinoma (HNSCC) is crucial because it improves the patient's prognosis and minimizes morbidity from treatment.
Objectives: To determine the efficacy of transoral robotic surgery (TORS) in identifying unknown primary sites of head and neck squamous cell carcinoma.
Design, setting, and participants: Retrospective, multi-institutional case series from January 1, 2010, to February 28, 2013, in which data were pooled from the following 6 institutions: University of Washington Medical Center, The University of Texas MD Anderson Cancer Center, University of Alabama-Birmingham Hospital, The University of Texas Medical School at Houston, Johns Hopkins Hospital, and Oregon Health Sciences University. All patients diagnosed as having HNSCC of an unknown primary site who underwent TORS to identify the primary site were included in the study. We excluded those with recurrent disease, a history of radiation therapy to the head and neck, or evidence of a primary tumor site based on previous biopsy results.
Main outcome and measure: Identification of the primary tumor site.
Results: Forty-seven patients were eligible for the study. The tumor site was identified by TORS in 34 of 47 patients (72.3%). The primary site was located in the base of tongue for 20 patients (58.8%) and the palatine tonsil for 13 patients (38.2%), with 1 patient having a primary site in both the base of tongue and the palatine tonsil. Suspicious physical examination findings were present in 23 of 47 patients (48.9%), with positive and negative predictive values of 56.5% and 25.0%, respectively. Of those who underwent any imaging, 16 patients had suspicious findings, with positive and negative predictive values of 50.0% and 16.7%, respectively. In 18 of 47 patients (38.3%), both preoperative radiographic and physical examination failed to suggest a primary site. Of these 18 patients, 13 (72.2%) were identified after undergoing TORS.
Conclusions and relevance: We demonstrate that TORS is a useful approach to identify and treat the primary site in patients with HNSCC who present with an unknown primary site.