Trends in incidence of primary cutaneous malignancies in children, adolescents, and young adults: a population-based study.

BACKGROUND: Skin cancer incidence among young adults is rising; however, the epidemiological characteristics of primary cutaneous lymphomas and cutaneous soft tissue sarcomas (CSTS) in individuals <30 years old has not been investigated. We analyzed the incidence and time-trends of primary cutaneous malignancies in children and adolescents/young adults (AYA). PROCEDURE: SEER-17 and -13 data were used to assess the descriptive epidemiology and time-trends in incidence of primary cutaneous malignancies in children and AYA. SEERStat and Joinpoint softwares were utilized to estimate annual percent changes (APC) in incidence.
RESULTS: In total, 7,814 cases (ASR = 25.66/1,000,000 habitants) of primary skin cancers in <30 years old were diagnosed in 2000-2008. Females had a higher incidence of melanoma (risk ratio (RR) = 1.95; P < 0.001) and a lower risk of developing CSTS (RR = 0.64, P < 0.001). Compared to whites, blacks have a lower incidence of melanoma (RR = 0.03, P < 0.001), and higher risk of CSTS (RR = 2.28, P < 0.001). Melanoma increased in females over a 15-year period (1992-2006) (APC = 2.5, 95%CI = 1.8; 3.2), and the incidence of cutaneous T-cell lymphomas increased over the period 1992-2008 (APC = 9.5, 95% CI = 6.7; 12.4). CSTS incidence decreased among males over the period 1992-1999 (APC = -21.4, 95% CI -27.2; -15.1), particularly due to a decrease in Kaposi sarcoma incidence (AAPC 1992-2008 = -13.6, 95% CI = -22.4;-3.8), although with a notable racial disparity (whites, AAPC = -15.2, 95% CI = -23.2;-6.4; blacks, AAPC = -10.6, 95% CI = -13.2;-7.9).
CONCLUSIONS: Non-melanoma skin cancer is very rare in children and AYA. We have shown variation in time-trends in incidence as well as in incidence patterns by race, sex, age, and histologic type, highlighting the importance of descriptive epidemiology to better understand the characteristics of these malignancies.