Characteristics and Prognosis Associated With Thin Nodular Primary Melanomas
In a study reported in the Journal of the National Cancer Institute, Dessinioti et al found that thin nodular primary melanomas are associated with aggressive characteristics that may portend poorer prognosis vs superficial spreading melanomas.
Study Details
The study involved data on 5,062 nodular melanomas and 15,070 superficial spreading melanomas diagnosed at 17 centers in Europe, the United States, and Australia between 2006 and 2015. Analysis was focused on thin melanomas (T1 ≤ 1.0 mm).
Features and Prognosis for Nodular Melanomas
Compared with T1 superficial spreading melanomas, T1 nodular melanomas were less likely to exhibit regression (odds ratio [OR] = 0.46, 95% confidence interval [CI] = 0.29–0.72) or nevus remnants (OR = 0.60, 95% CI = 0.42–0.85) and more likely to have mitoses (OR = 1.97, 95% CI = 1.33–2.93) and regional metastasis (OR = 1.77, 95% CI = 1.02–3.05). T1 nodular melanomas exhibited a higher mitotic rate vs T1 superficial spreading melanomas (adjusted geometric mean 2.2 vs 1.6 per mm2, P < .001).
On multivariate analysis, risk of melanoma-specific death was higher for both T1 nodular melanomas vs T1 superficial spreading melanomas (hazard ratio [HR] = 2.10, 95% CI = 1.24–3.56) and T2 nodular melanomas vs T2 superficial spreading melanomas (HR = 1.30, 95% CI = 1.01–1.68); however, risk remained significantly higher only for T1 melanomas after adjustment for center heterogeneity (HR = 2.20, 95% CI = 1.28–3.78). On multivariate analysis stratified for tumor spread, no increased risk of melanoma-specific death for nodular melanomas vs superficial spreading melanomas among each T stratum was observed among localized melanomas (OR = 1.08, 95% CI = 0.89–1.30) or cases of regional metastasis (OR =1.11, 95% CI = 0.94–1.32).
The investigators concluded, “T1 [nodular melanomas] (compared to T1 superficial spreading melanomas) [were] associated with a constellation of aggressive characteristics that may confer a worse prognosis. Our results indicate nodular melanoma is a high-risk melanoma subtype that should be considered for inclusion in future prognostic classifications of melanoma.”
Alexander J. Stratigos, MD, of the 1st Department of Dermatology-Venereology, National and Kapodistrian University of Athens, is the corresponding author for the Journal of the National Cancer Institute article.
Disclosure: Τhe study was supported by the Institute of Dermatologic Research and Education, the US National Institutes of Health, and others. The study authors’ full disclosures can be found at academic.oup.com.
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