Quantitative Assessment of Melanoma Spread in Sentinel and Non-Sentinel Lymph Nodes and Survival.

9082 Background: We have recently shown that quantification of cancer dissemination from melanoma to sentinel nodes is feasible and can be combined with other characteristics of the primary tumor to improve outcome prediction. Here we asked whether quantitative assessment of cancer spread to non-sentinel nodes could further improve outcome prediction. Methods: The study includes 128 melanoma patients with microscopic positive sentinel nodes who underwent complete lymph node dissection at the University of Tubingen. We analyzed 267 sentinel nodes and 1129 non-sentinel nodes from these patients by pathology and by quantitative immunocytology. For immunocytology half of the node was disaggregated mechanically, single cell suspensions were dispensed onto slides, stained with the melanoma specific antibody gp100. For each node we recorded the disseminated cancer cell (DCC) density, defined as the number of gp100 positive cells per million lymph node cells examined. Results: Quantitative immunocytology showed m...