Prediction score for lymph node metastasis from cutaneous squamous cell carcinoma of the external ear

AimsThe frequency of lymph node metastasis (LNM) is higher in cutaneous squamous cell carcinoma (cSCC) of the ear than in other head and neck cSCCs. Nodal dissemination is associated with a significantly worse prognosis and disease-specific survival. The aim of this study was to establish a prediction model for LNM in patients with cSCC of the ear.Materials and methodsTumour characteristics of 353 patients with ear cSCC were analysed to assess differences between those with and without LNM and to calculate a prediction score for LNM occurrence.ResultsRegional LNM occurred in 10.5% of patients. Five-year disease-specific survival was significantly lower in the LNM group than in the control group (59% vs. 99%; p < 0.001). Recurrence number, invasion of cartilage, tumour depth, and tumour grading were the most important predictors for LNM, with correct prediction of LNM in 94.0% of cases. Our prediction score stratified patients into high and low risk groups (p < 0.001) with a sensitivity of 89.2%, a specificity of 94.6%, and an overall accuracy of 94.1%.ConclusionOur new prediction model was able to accurately identify patients at high risk of LNM who may benefit from elective lymph node surgery.