Lymph node retrieval rates in melanoma: a quality assessment parameter.

INTRODUCTION: Regional lymph node dissection (rlnd) for melanoma with nodal metastasis is a specialized procedure that is associated with improved disease-specific survival in selected patients. Furthermore, there is evidence that a higher lymph node retrieval rate (lnrr) is associated with improved local control. Currently, no consensus has been reached on the definition of an adequate lnrr. A minimum lnrr has been proposed as a quality assessment parameter that has to be validated. METHODS: We conducted a retrospective cohort analysis at the Princess Margaret Cancer Centre (University Health Network, Toronto, ON). The lnrrs for all patients who underwent rlnd for malignant cutaneous melanoma during 2000-2010 were recorded. Indications for rlnd were a positive sentinel lymph node biopsy or clinical lymphadenopathy (palpable or radiologically detected). RESULTS: Of the 207 identified rlnds, 146 (70.5%) were subsequent to a positive sentinel lymph node biopsy, and 61 (29.5%) were performed for clinical lymphadenopathy. The median lnrr was 24 nodes (range: 9-47 nodes; 10th percentile: 14 nodes) for axillary rlnd, 12 nodes (range: 5-30 nodes; 10th percentile: 8 nodes) for inguinal rlnd, and 16 nodes (range: 10-21 nodes; 10th percentile: 11 nodes) for ilioinguinal rlnd. The results were similar when comparing patients with positive sentinel lymph nodes and those with clinical lymphadenopathy, and the same surgical techniques were used in both groups. CONCLUSIONS: The lnrrs at our institution are similar to rates reported at other tertiary-care melanoma centres. A minimum acceptable lnrr can be considered a quality assessment parameter in the surgical management of melanoma with nodal metastasis.