Congratulations to Andrea Maurichi for publication of his paper, ‘Factors Affecting Sentinel Node Metastasis in Thin Cutaneous Melanomas’, in the current issue of Journal of Clinical Oncology! I am thrilled to be a co-author.
This paper provides a nomogram that assists the clinician in determining the likelihood of positive results of sentinel lymph node biopsy (SNB) for thin melanoma (T1, ≤1 mm). https://ascopubs.org/doi/abs/10.1200/JCO.19.01902. We propose the nomogram as a decision aid in patients with T1 melanoma being considered for SNB.
The development cohort included 3,666 patients with T1 disease treated at the Istituto Nazionale Tumori (Milan, Italy) between 2001 and 2018. Patients treated at 13 other European centres formed the validation cohort (4,227 patients with T1 disease).
Within the development cohort, 1,635 underwent SNB; 108 patients (6.6%) were SN positive. Age, growth phase, Breslow thickness, ulceration, mitotic rate, regression, and lymphovascular invasion were significantly associated with SN status by univariable analysis. The random forest procedure selected 6 variables (not growth phase) for inclusion in the logistic model and nomogram. The nomogram proved well-calibrated and had good discriminative ability in both cohorts.