Non-radical primary diagnostic biopsies affect survival in cutaneous head and neck melanoma

Background: It is unclear if a non-radical diagnostic biopsy entails a higher risk for metastasis and poorer survival for patients with cutaneous head and neck melanoma (cHNM). Aims/objectives: To assess whether or not initial diagnostic biopsy modality and radicality (clear, positive, or narrow histopathological margins) influence recurrence and survival in patients with cHNM. Materials and methods: Histopathological radicality of initial diagnostic biopsies and outcome for 368 consecutive cHNM patients, clinically asymptomatic of metastatic disease and referred to a tertiary care academic center for sentinel lymph node staging from 2004 through 2018, were retrospectively analyzed. Results: Patients with positive (n = 133) or narrow (0.1–0.5 mm) (n = 34) histopathological margins had significantly worse loco-regional (p=.004) and distant control (p=.004) as well as lower overall (p=.017) and melanoma specific (p=.0002) survival than 201 patients with clear margins. Multivariate analysis indicated positive or narrow histopathological margins as independent negative prognostic factors for melanoma specific survival (HR 2.16, p=.015), together with deeper Breslow (HR 1.17, p=.00001) and ulceration (HR 2.49, p=.003). Conclusions and significance: Non-radical primary diagnostic biopsies increase the risk for metastatic disease and impair survival in cHNM. Accordingly, radical melanoma diagnostic procedures should be encouraged in the head and neck region when possible.