8005 Introduction: The SN procedure has become a widely used staging procedure for stage I/II melanoma patients. We previously reported on the high SN+ identification rate with the use of the EORTC MG group pathology protocol (van Akkooi et al., Eur J Cancer: 2006, in press). Because only approximately 20% of SN positive patients have additional non-SN lymph node involvement in the cLND specimen, we have proposed to identify a SN+ patient group, which can be spared a cLND. Therefore further microanatomic analyses of the metastatic SNs has been performed to identify patient/tumor or SN factors which predict DFS and OS as well as additional non-SN nodal positivity. Methods: 262 stage I/II pts were included into the SN database between 10/97 and 5/04. 77 were SN+ (29%). 74 pts had SN material for re-evaluation in this study. Microanatomic analysis categorized a.o. the location of tumor cells; subcapsular, parenchymal (or combined), multifocal or extensive; the Starz classification and the measurement of the amount of tumor load (in mm). Tumor load was quantified by size: <0.1mm (single melanoma cells), 0.1 - 1.0mm, >1.0mm. DFS, OS and additional non-SN positivity was calculated for all the microanatomic analyses. Results: Mean/Median Breslow was 3.5/3.0 (0.8 - 12.0) mm, mean/median FU was 35/30 (6 - 81) months. There were no signif. differences in OS or additional non-SN positivity for the different loc. of involvement. The estimated 5yr OS rates were 100%, 63% and 35% for the different groups of tumor load, <0.1mm, 0.1 - 1.0mm, >1.0mm respectively (Figure)(P=0.03). There were no patients with add. non-SN positivity in the group with involvement <0.1mm. On multivariate analysis the tumor load was the most important prognostic factor for DFS (P=0.005) and OS (P=0.03). DFS, OS and add. non-SN positivity of all other analyses will be presented at the meeting. Conclusions: It is questionable whether SN with onlysingle cells involvement (<0.1mm) should be considered positive. Dist. mets are exceedingly rare (1/16 = 6.3%) and was identical to the SN- patient pop., and non-sentinel node involvement was not observed at all. These patients should probably not undergo add. LND and may not be considered stage III patients. No significant financial relationships to disclose.
Corrigendum to “Timing of sentinel node biopsy independently predicts disease-free and overall survival in clinical stage I-II melanoma patients: A multicenter study of the Italian Melanoma Intergroup (IMI)” [Eur J Canc 137 (2020). Pages 30–39]
