Fatal thin melanoma: thickness of 0·80–1·00 mm are more hazardous thin lesions
April 19, 2020
Summary
Background: Thin cutaneous melanomas (≤ 1·00 mm) are increasing worldwide, causing around a quarter of all melanoma deaths in the U.S.A. and Australia. Identification of predictive factors for potentially fatal thin melanomas could allow better use of resources for follow-up.
Objectives: To identify the clinicopathological factors associated with fatal thin melanomas.
Methods: This large, nested case–case study extracted data from the population-based Queensland Cancer Registry, Australia. Our cohort consisted of Queensland residents aged 0-89 years who were diagnosed with a single, locally invasive thin melanoma (≤ 1·00 mm) between 1995 and 2014. Fatal cases (eligible patients who died from melanoma) were individually matched to three nonfatal cases (eligible patients who were not known to have died from melanoma) according to sex, age, year of diagnosis and follow-up interval. Using conditional logistic regression, we calculated odds ratios (ORs) for melanoma-specific death, adjusting for all collected clinicopathological variables.
Results: In the cohort, 27 660 eligible patients were diagnosed with a single, thin melanoma. The final case-case series included 424 fatal cases and 1189 nonfatal cases. Fatal cases were sixfold as likely to arise on the scalp as on the back [OR 6·39, 95% confidence interval (CI) 2·57–15·92] and six times as likely to be of thickness 0·80-1·00 mm as of < 0·30 mm (OR 6·00, 95% CI 3·55–10·17).
Conclusions: Scalp location is a strong prognostic factor of death from thin melanoma. Further, this study provides support that melanomas with a thickness of 0·80-1·00 mm are the more hazardous thin lesions. Patients with these tumour characteristics require specific attention during follow-up.
Source:
Claeson, M., Baade, P., Brown, S., Soyer, H., Smithers, B., Green, A., Whiteman, D. and Khosrotehrani, K. (2020), Clinicopathological factors associated with death from thin (≤ 1·00 mm) melanoma. Br J Dermatol, 182: 927-931. doi:10.1111/bjd.18560