The lifetime risk of white patients developing melanoma is currently estimated at 1 in 50, compared with 1 in 1,000 for black patients. Although darker-pigmented populations are consistently reported to have lower melanoma risk--possibly related to protection from ultraviolet radiation provided by melanin--darker skinned patients have been consistently shown to have worse outcomes than whites.
While less common in blacks, malignant melanoma is nonetheless an aggressive, deadly disease and presents at a more advanced stage at diagnosis and with a decreased chance of survival than in white patints. Underlying etiologies for the disparity in prognosis are still poorly understood.
Many of the public health interventions for melanoma prevention have focused predominantly on whites. However, recent studies in blacks and Hispanics that have elucidated advanced stage of melanoma at presentation and a higher mortality rate have led to increased efforts to characterize melanoma in ethnic minorities.
One such study found that ethnic disparities persist in the incidence of melanoma and its stage at diagnosis (Arch Dermatol. 2009;145:1369-74). Researchers analyzed information in the Florida Cancer Data System, a statewide, population-based cancer registry. They looked at three 5-year periods: 1990 to 1994, 1995 to 1999, and 2000 to 2004.
Of 41,072 cases of melanoma diagnosed from 1990 to 2004, 39,670 were in whites, 1,148 in Hispanics, and 254 in blacks. Advanced melanoma diagnosed at either regional or distant stages were seen in 26.4% of black patients, compared with 17.8% of Hispanics and 11.6% of whites. Blacks and Hispanic patients had advanced cancer odd ratios of 2.7 and 1.6, respectively, compared with whites.
The authors of the study concluded that public health efforts are one of the primary sources of ethnic disparities. However the question still remains: is race (and in essence a more aggressive tumor biology) an independent prognostic indicator?
Multiple studies have elucidated worse prognosis in blacks even when controlling for socioeconomic status, stage, tumor thickness, ulceration, anatomic site, and histological type. This data has been refuted in other studies that show no survival advantage in whites; however, the controversy still remains.
This study is a much needed reminder that increased surveillance is needed, as well as more targeted public health efforts, prevention models, and educational programs specific to the culture and languages of ethnic groups. We also need to continue to investigate the unique genetic and biologic markers of melanoma in different ethnic populations to improve clinical detection and develop targeted therapies.