Digital monitoring by whole body photography and sequential digital dermoscopy detects thinner melanomas

Abstract

Introduction: Population screening for melanoma remains controversial. There are no studies demonstrating that population screening increases survival. As prognosis of melanoma is directly related to Breslow thickness, a surrogate marker of survival is thickness of melanoma. The development of several self-referred, whole-body photography and sequential digital dermoscopy imaging services reflects the public's concern regarding melanoma.

Aim: To assess the ability of one of these services to detect melanoma at an early, thin stage.

Methods: Demographic and histological details from 100 melanomas diagnosed through self-referred whole-body photography and sequential digital dermoscopy imaging service compared to those diagnosed through traditional methods from data held by the New Zealand Cancer Registry.

Results: There were 52 invasive and 48 in-situ melanomas: 90% superficial spreading type, 6% lentigo-maligna type and 4% nodular on histology. Forty-eight were diagnosed on first visit; the remainder by serial digital dermoscopy. Thirty-five percent of patients reported having had previous primary melanoma. In 60%, patients had been concerned by the lesion, the rest (40%) detected solely by screening. Patients diagnosed by whole-body photography and sequential digital dermoscopy screening had thinner melanomas compared to the Registry data: 69% <0.75 mm Breslow thickness compared to 52% (p=0.0216); only 1.9% thicker than 3 mm compared to 10.8% (p=0.067).

Discussion: Melanomas detected by self-referred, whole-body photography with sequential digital dermoscopy service are thinner than melanomas detected by traditional diagnostic methods. It remains to be determined whether earlier diagnosis results in improved survival.