[528] Significance of Sentinel Lymph Node Isolated Tumor Cell Clusters in Overall Survival of Melanoma Patients.

Jeremy G Vincent, Joshua A Wisell, Jonathan D Cuda, Alexander T Hillel, William H Westra, Janis M Taube. The Johns Hopkins Hospital, Baltimore, MD; The University of Colorado, Denver; Stanford University, Palo Alto, CA

Background: Sentinel lymph node micrometastases are of prognostic significance in melanoma, and the 2010 AJCC classification cites no minimum volume criteria. Despite this recent codification, the prognostic significance of isolated tumor cells remains in question by many investigators and practitioners.
Design: Patients undergoing sentinel lymph node biopsy (SLNB) for Stage I/II melanoma at our institution between 1996 and 2005 were reviewed to identify patients with negative sentinel lymph nodes, those with micrometastases less than 0.2 mm in size, and those greater than 0.2 mm in size. Histologic and prognostic features of the primary melanoma were collected. The mean follow-up for patients was 4 years, with a median of 1.7 years.
Results: Of 122 patients who had a SLNB performed, 19 had micrometastases less than 0.2 mm in size in their SLN, and 53 had metastases greater than 0.2 mm. All microdeposits of melanoma stained positive with the melanocytic markers Melan-A and HMB-45 by immunohistochemistry. The Kaplan-Meier analysis of overall patient survival at 5 years was 94% in patients with negative SLN, 80% in patients with metastases <0.2mm, and 62% in patients with metastases>0.2mm (p=0.0037).

Conclusions: Patients with isolated tumor cells and very small deposits of melanoma less than 0.2 mm in size have a worse prognosis than patients with a negative SLNB. Accordingly, even isolated tumor cells in the lymph nodes of patients with melanoma should be interpreted as positive, allowing for additional therapeutic options including completion lymphadenectomy and experimental protocols.
Category: Dermatopathology

Tuesday, March 1, 2011 9:30 AM

Poster Session III # 109, Tuesday Morning


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