Outcomes of thyroid cancer in African Americans.

Context: Thyroid cancer, the most common endocrine cancer, is on the rise. It is less common in the African American (AA) population in the United States. Few studies have looked at outcome disparities for different patient populations, particularly those involving race.

Objective: Using data from the SEER registry, we sought to determine whether five-year survival differed significantly between AA and White patients and, whether differences were due to patient or disease characteristics.

Design: Retrospective cohort analysis. Univariate comparisons were made using Student-t tests for continuous variables, chi-square tests for categorical variables. Survivor functions were estimated using Kaplan-Meier curves, and comparisons were made by log rank tests.

Setting And Patients: 26,902 patients (25,210 White and 1,692 AA) were diagnosed with thyroid cancer between 1992 and 2006.

Main Outcome Measure(s): Five-year survival defined as time from diagnosis to death from cancer within five years.

Results: AA had a significantly lower rate of five-year survival compared to Whites (96.5% vs 97.4%, P = .006). AA patients were 2.3 times more likely to be diagnosed with anaplastic disease (Risk ratio [RRI = 2.33 (95% CI: 1.52-3.58), P = .0001), and were also nearly 80% more likely to be diagnosed with follicular disease (RR = 1.78 [95% CI: 1.59-1.99], P < .0001). They were nearly twice as likely to have larger tumors (> or = 4 cm) than White patients (RR = 1.94 [95% CI: 1.78-2.12], P < .0001).

Conclusions: AA had poorer survival from thyroid cancer relative to White patients; this difference may be explained by differences in disease characteristics such as a relatively higher rate of anaplastic thyroid cancer, follicular cancer and larger tumors at presentation.