Histologic margin status predicts relapse in lentigo maligna melanoma

Histologic margin status shows a robust association with progression for lentigo maligna melanoma, suggest the results of a recent study.

To determine whether histologic margin status independently predicted progression, the authors analysed the clinicopathologic information of 268 patients with an invasive lentigo maligna melanoma diagnosis between 1990 and 2019. A Cox proportional hazards model and the Boruta method were used to carry out statistical analyses.

Of the lesions assessed, 75 percent were located on the head and neck. Patients had a median follow-up of 10.2 years (range 0 to 31.8 years). The median time to local recurrence was 3 years (range 0 to 20 years). Fifty-four individuals (20.1 percent) developed progression.

Of the patients, 36 (13.4 percent) had local recurrence only, seven (2.6 percent) had both local recurrence and subsequent metastasis, and 11 (4.1 percent) had metastasis only.

Histologic margin status (positive and close/<3 mm) and tumour site (head and neck location) were significantly associated with worse progression-free survival.

“Histologic margin status is the strongest predictor of progression for lentigo maligna melanoma,” the authors said. “Patients with positive or close/<3 mm histologic margins should consider a re-excision due to the increased risk of relapse.”

The study was limited by its single-institution and retrospective design.