Although uncommon, melanoma is associated with poor survival characteristics among African Americans and Hispanics compared with non-Hispanic whites (NHWs). Low socioeconomic status (SES) is also associated with poor survival among patients with melanoma, but it is not known whether this is because of SES itself or because of treatment disparities. We set out to determine this by using the large, population-based California Cancer Registry (CCR) database as a model.
We conducted a case-only analysis of CCR data (1993 to 2003), including a descriptive analysis of relevant clinical variables and SES. The SES variable used has been derived from principle component analysis of census block-level CCR data that was linked to census data to address seven indicators of SES. Univariate analyses of overall survival (OS) were conducted using the Kaplan-Meier method. Multivariate survival analyses were performed using Cox proportional hazard ratios (HRs).
A total of 39,049 incident patient cases of cutaneous melanoma, including 36,694 in NHWs; 127 in African Americans; 1,996 in Hispanics; and 262 in Asian-Americans, were analyzed. Higher SES was associated with an early stage at presentation (P < .0001), with treatment with surgery (P = .0005), and with prolonged survival (P < .0001). After adjustments for age, sex, histology, American Joint Committee on Cancer stage, anatomic site, treatment, and SES, a statistically significant increased risk of death was observed for African Americans compared with NHWs (HR, 1.60; 95% CI, 1.17 to 2.18); no survival differences were noted for Asians or Hispanics compared with NHWs in the adjusted analysis.
Low SES independently predicts poor outcome among patients with cutaneous melanoma. However, the poor OS observed for African American patients with melanoma is not explained by differences in treatment or SES.