Exploring tonsillar cancer associations in patients with base of tongue cancer: insights from a single-center study.

Purpose: To explore the prevalence of synchronous and metachronous tonsillar cancer in patients with base of tongue cancer, as well as identifying potential risk factors linked to these secondary malignancies. We aim to answer the following question: Should bilateral tonsillectomy be recommended to patients diagnosed with base of tongue cancer?

Methods: A case-series study was conducted at Aarhus University Hospital, including all patients with histologically confirmed base of tongue squamous cell carcinoma treated between January 2012 and December 2021. Data from electronic patient records, including diagnosis of prior, synchronous or metachronous tonsillar cancer, demographics, and clinical features were analysed. Fisher's exact test was performed to assess factors associated with synchronous and metachronous tonsillar cancer.

Results: Among 198 patients with base of tongue cancer, 5.6% had a history of tonsillar cancer, either prior to (4.5%), synchronous (0.5%), or metachronous (0.5%) to the base of tongue diagnosis. The prevalence of synchronous or metachronous tonsillar cancer among patients without previous bilateral tonsillectomy was 1.2%. Patients with tonsillar cancer were older, had heavier smoking histories, and exhibited less frequent P16-overexpression.

Conclusion: Our findings deepen understanding of tonsillar cancer in patients with base of tongue cancer. The prevalence of synchronous or metachronous tonsillar cancer was found to be relatively low, suggesting that routine tonsillectomy for all base of tongue cancer patients is not warranted.