Recurrence, mortality rates better in nevus-associated vs. de novo acral melanoma

Key takeaways:

• Five-year recurrence-free survival was 55.1% with nevus-associated acral melanoma (NAAM) vs. 42.3% with de novo acral melanoma (DNAM).
• Overall 5-year survival was 75.1% vs. 63.2% in the NAAM vs. DNAM groups.

Recurrence-free survival and overall survival were more common in patients with nevus-associated acral melanoma compared with those with de novo acral melanoma, according to a study.

“Nevus-associated melanoma (NAM) refers to melanoma that either contains residual nevus components, as observed in histopathological examination, or originates from a pre-existing melanoma,” Yiqun Zhang, MM, of the department of oncology at the First Hospital of Jilin University, and colleagues wrote. “Patients with NAM show better overall survival (OS) compared to those with de novo melanoma (DNM).”

A subtype of NAM, acral melanoma (AM) occurs on the palms, soles and nails and is more common in people with skin of color.

Zhang and colleagues conducted a multicenter, retrospective study of 684 native Chinese patients with AM, of whom 482 were included in the final analysis. Nevus-associated acral melanoma (NAAM) was present in 34% of patients and de novo acral melanoma (DNAM) was diagnosed in 66%. All patients were undergoing radical surgery.

Using the Kaplan-Meier method, the researchers estimated survival curves and calculated recurrence-free survival and overall survival.

The median recurrence-free survival was 46.6 months, with rates of 74.8% for 1 year, 53.5% for 3 years and 46.9% for 5 years. The median overall survival was 106.9 months, with rates of 95.9% at 1 year, 80.6% at 3 years and 67.6% at 5 years.

Recurrence-free survival rates were better in the NAAM group, with a median survival of 96.1 months and survival rates of 77.7% for 1 year, 61.6% for 3 years and 55.1% for 5 years. This compared with a median survival of 34.2 months and rates of 73.2%, 49% and 42.3%, respectively, in the DNAM group.

Median overall survival was 89.4 months in the DNAM group and was not reached in the NAAM group. Overall survival at 1, 3 and 5 years was 98.1%, 87.4% and 75.1% in the NAAM group and 94.7%, 76.8% and 63.2% in the DNAM group.

In a multivariate analysis, the authors found nevus association was linked to better recurrence-free and overall survival. Thicker Breslow thickness and positive sentinel node status were noted predictors of poorer recurrence-free survival. These were also predictors of worse overall survival, along with older age, lymphovascular invasion and ulceration.

The authors said the study was limited by its retrospective design and missing data.

“This study highlighted notable differences in recurrence and survival outcomes between patients with NAAM and DNAM,” the authors wrote. “However, the biological mechanisms behind these differences remain unclear.”

Further studies are warranted to explore how nevus association affects recurrence and survival, they added.