Impact of Soft Palate Involvement on the Outcome of Definitive (Chemo)radiotherapy for Tonsillar Squamous Cell Carcinoma

ABSTRACT Background To analyze the impact of soft palate involvement on survival outcomes of patients with tonsillar carcinoma treated with definitive (chemo)radiotherapy. Methods A total of 402 patients treated between January 2010 and December 2023 were included. Results Soft palate was involved in 170 patients. A complete response was achieved in 381 patients. Locoregional recurrence occurred in 26 patients (6.5%) and distant metastasis in 56 patients (13.9%). For the whole group, the 5‐year rates for local control, disease‐free survival, disease‐specific survival, and overall survival were 92.6%, 74.6%, 80.6%, and 74.8%, respectively. Smoking status, nodal stage, systemic treatment and soft palate involvement were identified as prognostic factors. The rate of distant metastasis was significantly higher in patients with soft palate involvement (19.4% vs. 9.9%; p = 0.0066). Conclusion To the best of authors' knowledge, we report the first study to analyze the impact of soft palate involvement on outcomes for patients with tonsillar cancer treated with (chemo)radiotherapy. The incidence of local recurrence is low; however, the rate of distant metastasis is high and is significantly higher in patients with soft palate involvement.