Clinical characteristics of melanoma in an ethnically diverse population of adolescents and young adults.

Abstract

e21043 Background: Melanoma is the third most common cancer among adolescents and young adults (AYAs; aged 15-39). Disease characteristics have not been well-described in this age group, particularly among diverse populations. We describe clinical features of AYAs diagnosed with melanoma at a large public hospital serving an ethnically diverse population. Methods: We reviewed medical chart data from patients diagnosed with melanoma between 2001-2016 at Los Angeles County + USC Medical Center. We describe clinical characteristics of AYA patients and compare to non-AYAs (aged ≥40) using Fisher’s exact test. A p-value < 0.05 was considered statistically significant. Results: Of the 273 melanoma patients identified, 47 (17.3%) were AYAs (mean age 32.3; SD±4.45; lower age range 18). The majority of patients were Hispanic (AYA, 53.2%; non-AYA, 51.1%), followed by non-Hispanic whites (AYA, 38.3%; non-AYA, 38.7%). A greater proportion of AYA patients were female (59.6%) compared to non-AYAs (38.2%) (p < 0.01). No AYA patients reported prior skin cancer compared to 19.9% of non-AYAs; 8.5% of AYAs reported family history of melanoma compared to 6.3% of non-AYAs. For all patients, superficial spreading melanoma was the most common histological subtype (AYA, 21.3%; non-AYA, 20.9%). Nodular melanoma was the second most common subtype in AYAs (17.02%) in contrast to acral lentiginous melanoma among non-AYAs (20.9%). Median Breslow depth was 3.0 mm for AYAs and 2.55 mm among non-AYAs. A slightly higher percentage of AYAs were diagnosed with regional disease (31.9%) than non-AYAs (24.4%), and a greater proportion of non-AYAs presented with distant metastases (AYA, 6.4%; non-AYA, 18.7%). The most common site of diagnosis were the extremities for all patients (AYA, 45.0%; non-AYA, 29.3%). Conclusions: We found similar clinical characteristics between AYA and non-AYA melanoma patients. However, we found a statistically significant difference for gender. The increased incidence of melanoma in female AYAs may be driven by biological factors such as sex hormones or genotype, or tanning behaviors. Further research is warranted to identify predictive and prognostic factors of melanoma among diverse AYAs, particularly females.