Second Primary Tumors in Patients Presenting With Unilateral HPV-Associated Tonsillar Squamous Cell Carcinoma

Objective To describe and compare rates of metachronous and synchronous second primaries of the contralateral tonsil in patients with primary HPV(+) tonsillar squamous cell carcinoma (SCC). Study Design Retrospective cohort study. Materials and Methods This is a single tertiary care center retrospective case series, from 2006 to 2019, of HPV(+) tonsillar SCC patients who underwent primary surgical resection with unilateral wide-field tonsillectomy or bilateral tonsillectomy for diagnostic or therapeutic purposes. A metachronous second primary is one diagnosed >6 months after completion of surgical treatment. A synchronous second primary is one diagnosed during bilateral tonsillectomy for unilateral HPV(+) tonsillar SCC. Rates of second primary and patient characteristics were compared using chi-square tests. Results About 303 patients underwent unilateral surgical resection +/- adjuvant therapy for HPV(+) tonsillar SCC. One (0.3%) developed a metachronous second primary in the contralateral tonsil 11.9 years following treatment. Fifty-seven patients with HPV(+) tonsillar SCC underwent bilateral tonsillectomy, and 37/57 (65%) had no clinical signs for contralateral disease. Of these, only 1/37 (2.7%) was incidentally found to have a synchronous second primary. Twenty patients underwent bilateral tonsillectomy due to clinical concern for contralateral disease. Of these, 3/20 (15%) were found to have a synchronous HPV(+) SCC in the contralateral tonsil. Conclusions The prevalence of metachronous second primary after appropriate treatment of HPV(+) tonsillar SCC is very low (0.3%) and so is the chance of incidentally discovering a synchronous second primary during bilateral tonsillectomy (2.7%). We do not recommend bilateral tonsillectomy as a part of the routine algorithm in the surgical management of these patients. Level of Evidence 3 Laryngoscope, 2021

Automated summary

The study compared rates of metachronous and synchronous second primaries of the contralateral tonsil in patients with primary HPV(+) tonsillar squamous cell carcinoma. The prevalence of metachronous second primaries after appropriate treatment was very low (0.3%), as was the chance of incidentally discovering a synchronous second primary during bilateral tonsillectomy (2.7%). It was concluded that bilateral tonsillectomy should not be routine in the surgical management of these patients.