Comparison of Thin Nodular Primary Versus Superficial Spreading Melanomas
Posted: Tuesday, May 14, 2019
Thin nodular melanomas, compared with thin melanomas of other subtypes, seem to be associated with worse outcomes, according to a study by Clio Dessinioti, MD, PhD, of the National and Kapodistrian University of Athens, and colleagues. Of the four melanoma subtypes, data on thin nodular melanomas, in particular, are sparse. The authors’ findings, which were published in the Journal of the National Cancer Institute, suggest “aggressive screening for earlier detection of this [melanoma] subtype” may benefit patients.
In this international study, data from 20,132 nodular and superficial spreading melanomas were culled from 17 centers and analyzed using multivariate logistic regression analysis. Of the 9,681 T1 melanomas, defined as having a Breslow thickness of up to 1.0 mm, 3.2% were nodular melanomas. The majority of these tumors (72.4%) were 0.8 mm or thicker, whereas the majority of superficial spreading melanomas were less than 0.5 mm thick.
Compared with T1 superficial spreading melanomas, T1 nodular melanomas had higher mitotic rates (P < .001), were less likely to regress, and were less likely to be associated with nevus remnants. Furthermore, T1 nodular melanomas were more commonly associated with the head and/or neck and were more likely to exhibit regional metastasis. The 5-year melanoma-specific survival rate was also lower in T1 and T2 nodular melanomas (P < .001 and P = .009, respectively).
“Our results indicate [nodular melanoma] is a high-risk melanoma subtype that should be considered for inclusion in future prognostic classifications of melanoma,” the authors concluded.
Disclosure: The study authors’ disclosure information may be found at academic.oup.com.