Trends by race and ethnicity in incidence and mortality of acral lentiginous melanoma: analysis of Surveillance, Epidemiology, and End Results 2000-2020.

ABSTRACT

Limited data describe the epidemiology and risk factors of acral lentiginous melanoma (ALM). In this retrospective analysis, we examined trends in incidence and mortality of ALM among racial and ethnic minoritized populations. We queried 22 Surveillance, Epidemiology, and End Results registries for cases of ALM among Hispanics, non-Hispanic Asians or Pacific Islanders (NHAPIs), non-Hispanic Blacks (NHBs), and non-Hispanic Whites (NHWs) from 2000 through 2020. Age-adjusted incidence and annual percentage changes (APCs) were estimated. Kaplan-Meier curves were stratified by race and ethnicity and compared with log-rank tests. Cox proportional hazard regression models were adjusted for age, sex, race, ethnicity, income, urban-rural residence, stage, and treatment. Of 4188 total cases of ALM with complete data, our study cohort was comprised of 792 (18.9%) Hispanics, 274 (6.5%) NHAPIs, 336 (8.0%) NHBs, and 2786 (66.5%) NHWs. The age-adjusted incidence of ALM increased by 2.48% (P < 0.0001) annually from 2000 to 2020, which was driven by rising rates among Hispanics (APC 2.34%, P = 0.001) and NHWs (APC 2.69%, P < 0.0001). Incidence remained stable among NHBs (APC 1.15%, P = 0.1) and NHAPIs (APC 1.12%, P = 0.4). From 2000 through 2020, 765 (18.3%) patients died from ALM. Compared to NHWs, Hispanics, NHAPIs, and NHBs had significantly increased ALM-specific mortality (all P < 0.0001). Unadjusted and adjusted cause-specific mortality modeling revealed significantly elevated risk of ALM-specific mortality among Hispanics (hazard ratio [HR] 1.46, 95% confidence interval [CI] 1.22-1.75; adjusted hazard ratio [aHR] 1.38, 95% CI 1.14-1.66), NHAPIs (HR 1.80, 95% CI 1.41-2.32; aHR 1.58, 95% CI 1.23-2.04), and NHBs (HR 1.98, 95% CI 1.59-2.47; aHR 2.19, 95% CI 1.74-2.76) (all P < 0.001). Our study finds rising incidence of ALM among Hispanics and NHWs along with elevated risk of ALM-specific mortality among racial and ethnic minoritized populations. Future strategies to mitigate health inequities in ALM are warranted.