There is evidence that melanoma patients from poorer socioeconomic backgrounds present with thicker lesions. We compared the strength of this association between men and women and examined whether a similar trend exists for nodular melanoma, the most common type of thick melanoma and the most aggressive of all melanomas.
A population-based retrospective analysis was performed on 35,640 adult melanoma cases notified to the Queensland cancer registry between 1995 and 2009. Patients were divided into deciles of socioeconomic status (SES) based on 2006 census data. Melanoma thickness and the likelihood of nodular melanoma diagnosis were regressed against SES decile controlling for age and stratified by sex.
There is a significant linear trend between melanoma thickness and decreasing socioeconomic status in men, with lesions becoming 0.020 mm thicker with every unit drop in SES decile (95% confidence interval [CI] 0.01-0.03, p < 0.001). The trend is much weaker in women (0.005 mm, CI -0.02-0.02, p = 0.325). Similarly, the frequency of nodular melanoma increased with decreasing socioeconomic index in men (relative risk ratio [RRR] 1.05 per SES decile drop, CI 1.03-1.07, p < 0.001) but only slightly in women (RRR 1.02, CI 0.99-1.04, p = 0.139). Nodular melanoma rates do not account for the relationship between lesion thickness and SES in men, however, as the association remains even when all nodular melanomas are excluded (0.021 mm, CI 0.01-0.03, p < 0.001). The trends suggest that men from the lowest SES decile present with 18% thicker lesions and 1.6 times higher rate of nodular melanoma than men from the highest SES decile.
Men from socioeconomically disadvantaged areas have the highest risk of developing the most invasive form of melanoma, and even those with less aggressive forms tend to present with thicker lesions. Melanoma prevention measures and initiatives could have immediate outcomes if targeted at this group.