Are Thin, Early-Stage Nodular Melanomas Really Low-Risk?

May 23, 2019

A recent study evaluated whether longstanding assumptions that thin nodular melanomas are less aggressive than thicker ones are accurate.

Even thin T1 nodular primary melanomas are associated with “a constellation of aggressive characteristics” that might worsen patient prognosis compared with superficial spreading melanoma, according to findings from an international study published in the Journal of the National Cancer Institute.

The findings challenge longstanding assumptions about the life-threatening aggressiveness of nodular melanomas.

Nodular melanoma accounts for a disproportionate number of melanoma deaths. That has long been widely assumed to be due to greater Breslow thickness at the time of diagnosis, Alexander J. Stratigos, MD, of the National and Kapodistrian University of Athens, Andreas Sygros Hospital, in Athens, told Cancer Network.

But the study’s results indicate that nodular melanomas, even when thin and early-stage, are a high-risk disease subtype, Stratigos said.

“The study puts the spotlight on the nodular melanoma subtype, highlighting the distinct clinicopathological and prognostic features independent of Breslow thickness and at an early stage of its evolution,” noted Stratigos.

The study included 20,132 melanomas diagnosed at 17 cancer centers in Europe, the United States, and Australia, including 5,062 nodular tumors. Multivariate analysis confirmed more than a two-fold risk for melanoma-specific death for patients with thin T1 (≤ 1.0 mm Breslow thickness) nodular melanomas compared with those with superficial spreading melanoma (T1 tumors: hazard ratio [HR], 2.10; 95% CI, 1.24–3.56; T2 tumors: HR, 1.30; 95% CI, 1.01–1.68).

“This work adds to the literature suggesting that nodular melanoma is a distinct and more aggressive biological melanoma subtype that may warrant closer surveillance for disease recurrence and may need to be incorporated into prognostic classification of this disease,” commented Richard Carvajal, MD, medical oncologist at the Columbia University Irving Medical Center in New York.

“The 5-year melanoma specific survival for superficial spreading melanoma was 97.6% versus 91.4% for nodular melanoma, although the median follow-up of these patients was limited to 32.1 months,” Carvajal cautioned.