Outcomes of HPV+ Oropharyngeal Carcinoma of Unknown Primary Following Transoral Robotic Surgery

Treatment of patients with head and neck squamous cell carcinoma of unknown primary (CUP) is challenging. Given the relative rarity of this condition and the recent use of primary transoral robotic surgery (TORS) in modern diagnostic and treatment algorithms, long-term oncologic outcomes are unclear. The objectives were to evaluate oncologic outcomes of patients treated with TORS for management of CUP.

This retrospective case series was conducted at a tertiary care academic medical center from 2010 to 2021. All patients with HPV-mediated CUP who underwent TORS-assisted endoscopy were included. CUP was defined as biopsy-proven squamous cell carcinoma in a cervical lymph node with uncertain primary location following standard-of-care clinical and radiologic assessment. Primary outcomes were recurrence-free survival and overall survival. Secondary outcomes included usage of radiation and chemotherapy.

In total, 157 patients were included in the study. Median follow-up time was 62 months. Primary tumor was identified in 88% of patients. Surgery alone was performed in 21%, although adjuvant therapy was recommended but declined in 13%. Adjuvant radiation was completed in 46% and adjuvant chemoradiation in 33%. Two-thirds of patients avoided chemoradiation. Overall survival was 94% and recurrence-free survival was 92% at 5 years.

In the largest reported experience to date of TORS-assisted management of CUP, we demonstrate that this approach facilitates a high rate of identification of occult mucosal malignancies and can eliminate the need for chemotherapy and potentially radiation therapy in select patients without compromising excellent oncologic and functional outcomes.