Long-term results of ultrasound guided fine needle aspiration cytology in conjunction with sentinel node biopsy support step-wise approach in melanoma

BACKGROUND: US-FNAC is a common diagnostic tool in the work-up of many cancers. Results in melanoma were initially poor (sensitivity 20-40%). Introduction of the Berlin Morphology criteria has shown potential improvement up to 65-80% in selected patients. AIM: This cohort study evaluates the long-term survival outcome of melanoma patients undergoing Ultrasound (US) guided Fine Needle Aspiration Cytology (FNAC) prior to sentinel node biopsy (SNB) or direct lymphadenectomy. METHODS: Between 2001 and 2010 over 1000 consecutive melanoma patients prospectively underwent targeted US-FNAC prior to SNB. The Berlin US morphology criteria: peripheral perfusion (PP), loss of central echoes (LCE) and balloon shape (BS) were registered. FNAC was performed if any factor was present. All patients underwent SNB or lymphadenectomy in case of positive FNAC. RESULTS: Median follow-up was 61 months (IQR 40-95). SN positivity rate was 21%. Survival analyses demonstrated that patients with positive US-FNAC had poor survival. After adjustment for SN status and other known prognostic features, patients with positive US-FNAC (hazard ratio (HR) 1.80, 95% CI 1.10-2.96) had worse survival than patients with normal US (reference). Patients with suspicious US and negative FNAC (HR 1.13, 95% CI 0.71-1.78) had survival comparable to patients with normal US. CONCLUSIONS: The long-term US-FNAC results support this step-wise approach to melanoma patients. Patients with positive US-FNAC have a poor survival and can be spared a SNB. Patients with suspicious US and negative FNAC should undergo SNB to detect microscopic occult disease. Completely US-FNAC negative patients might only require follow-up and no SN staging at all