Melanocytic Clefting Observed Using LC-OCT

tumor recurrence and metastasis.We evaluated the association of CNS metastasis with the 31-GEP test result.Methods: A retrospective analysis of stage I-II CM patients clinically tested with the 31-GEP (2013-2017) (n=1,662).Kaplan-Meier analysis was used to estimate 5-year recurrence-free survival (RFS), and the log-rank test was used to compare survival between groups.Patients without CNS metastasis were censored at the time of last follow-up.Univariate analysis to identify predictors of CNS metastasis was performed for tumor location, mitotic rate, Breslow thickness, ulceration, tumor-infiltrating lymphocytes, age, sex, regression, lymphovascular invasion, tumor subtype, and 31-GEP result.Only significant (p<0.01)factors in univariate analysis were included in Cox multivariable analysis.Results: Median follow-up time was 4.6 years (range=0.02-14.5 years).Patients with CNS metastasis had thicker tumors (median 1.1 vs. 0.8, p=0.003), higher mitotic rate (median 2.5 vs. 1.0, p<0.001), and a higher proportion of males (73 vs. 55%, p=0.03) than those without CNS metastasis.Patients with a Class 2B result were significantly more likely to develop CNS metastasis (7.4%, 15/ 202) than those with a Class 1B/2A (1.7%, 5/291) or Class 1A (0.9%, 10/1,169; p<0.001).Patients with a Class 2B had significantly lower 5-year RFS than patients with a Class 1B/2A or Class 1A (91.6% vs. 98.2% vs. 99.1%,p<0.001) and shorter times to CNS metastases (1.5, 4.2, vs. 3.4 yrs.p<0.001).In multivariable analysis, only the 31-GEP Class 2B (HR=9.42,p<0.001) was a significant predictor of CNS metastasis; mitotic rate, Breslow thickness, and ulceration were not significantly predictive.Conclusions: In multivariable analysis, the 31-GEP was the only significant predictor of CNS metastasis, and CNS metastasis occurred early (1.5 yrs).Patients with stage I-II CM and a Class 2B result should be considered for imaging to enable asymptomatic detection of CNS metastasis and, thus, improve survival relative to symptomatic CNS metastasis.