Melanoma in US Hispanics: Recommended Strategies to Reduce Disparities in Outcomes
Cutaneous melanoma is the most fatal form of skin cancer and presents a considerable public health concern in the United States. Although the age-adjusted incidence of melanoma among US Hispanics is lower than that of non-Hispanic whites (NHWs), Hispanics who are diagnosed with melanoma are more likely to present with thicker primary tumors, metastatic disease, and lower 5-year melanoma-specific survival rates than NHWs. Melanoma risk factors and reasons for late presentation among Hispanics are not completely understood. In this review, the epidemiology and clinical presentation of melanoma in Hispanics is summarized, and recommendations for a research agenda to advance understanding of this disease in the most rapidly growing segment of the US population is provided.
Practice Points
- Although the age-adjusted incidence of melanoma among US Hispanics is lower than among non-Hispanic whites, Hispanics with melanoma are more likely to present with stage III disease and have distant metastases.
- Late presentation of melanoma in Hispanics is not completely understood but may be attributed to socioeconomic factors, lack of skin cancer awareness and knowledge, lower rate of self- and physician-performed skin examinations, and differences in tumor biology, among other variables.
- Research is needed to address gaps in knowledge about the risk of melanoma and comparatively poor outcomes among Hispanics so interventional efforts for prevention, early detection, and treatment can be implemented.
Demographic and Clinical Characteristics of Melanoma in Hispanic Patients
Among Hispanics, white Hispanics comprise the majority of melanoma cases.5 Median age at diagnosis is younger in Hispanics compared to whites.5,6 Hispanic men typically are older (median age, 61 years) than Hispanic women (median age, 52 years) at diagnosis.5 Similar to what is seen in NHWs, young Hispanic women experience a higher melanoma incidence than young Hispanic men.5 Among older Hispanics, melanoma is more common in men.5,8
Melanomas located on the lower extremities and hips are more prevalent in Hispanics than in NHWs.5,8,18 Among Hispanics, there are age- and sex-based variations in the anatomic location of primary tumors: in Hispanic men, truncal tumors predominate, and in Hispanic women, tumors of the lower extremities are most common across all age groups.5 The incidence of melanomas located in the head and neck region increases with age for both Hispanic men and women.
For melanomas in which the histologic type is known, superficial spreading melanoma is the most common subtype among Hispanics.5,17,19 Acral lentiginous melanomas and nodular melanomas are more common among Hispanics than among NHWs.5,17,19
,The observation that Hispanics with melanoma are more prone to lower-extremity tumors and nodular and acral lentiginous melanoma subtypes than NHWs suggests that UV exposure history may be of less importance in this population. Although numerous studies have explored melanoma risk factors in NHWs, there is a striking paucity of such studies in Hispanics. For example, there are conflicting data regarding the role of UV exposure in melanoma risk among Hispanics. Hu et al20 found that UV index and latitude correlated with melanoma risk in this population, whereas Eide et al21 found no association between UV exposure and melanoma incidence in Hispanics. A prospective study involving a multiethnic cohort (of whom 40 of the 107 participants were Hispanic) found no clear association between a history of sunburn and melanoma risk in Hispanics.18
Strategies for Reducing Disparities in Outcomes
Our knowledge of melanoma epidemiology in Hispanics derives mainly from secondary analyses of state-level and national cancer registry data sets.5-8,13-15,17,19,20 These administrative data sources often are limited by missing data (eg, tumor thickness, histologic subtype) or lack important patient-level information (eg, self-identified race and ethnicity, health insurance status). Additionally, the manner in which data are collected and integrated into research varies; for example, socioeconomic measures often are reported as either area-based or composite measures.
The host phenotypic characteristics of melanoma in NHWs are well understood, but the biological and environmental determinants of melanoma risk in Hispanics and other minorities are unknown. For example, fair complexion, red hair, blue eyes, increased freckling density, and the presence of numerous dysplastic and common melanocytic nevi indicate a propensity toward cutaneous melanoma.23,24 However, the relevance of such risk factors in Hispanics is unknown and has not been widely investigated in this patient population. Park et al18 found that a person’s sunburn susceptibility phenotype (defined as hair and eye color, ability to tan, and skin reaction to sunlight) was associated with an increased risk of melanoma among nonwhite, multiracial individuals. However, this study was limited by a small number of minority cases, which included only 40 Hispanic participants with melanoma.18 There is a need for rigorous observational studies to clearly define the phenotypic characteristics, sun-exposure behavior patterns, and genetic contributors to melanoma genesis in Hispanics.
The biologic determinants of postdiagnosis survival in Hispanics with melanoma are not well understood. It is unknown if genetic predisposition modifies melanoma risk in Hispanics. For example, the frequency of BRAF gene mutation or other driver mutations in US Hispanics has been understudied. It is important to know if mutation frequency patterns differ in Hispanics patients compared to NHWs because this knowledge could have considerable implications for treatment. Several recommendations should be considered to address these knowledge gaps. First, there is a need for development or enhancement of melanoma biorepositories, which should include tumor and nontumor specimens from a diverse sample of melanoma patients.
