Racial and socioeconomic disparities in presentation and outcomes of well-differentiated thyroid cancer.

Abstract

Racial/ethnic minorities suffer disproportionate morbidity and mortality from chronic diseases. Our objective was to assess racial and socioeconomic status (SES) disparities in well-differentiated thyroid cancer (WDTC) patients. We conducted a retrospective cohort study on 25 945 patients with WDTC (1999-2008) from the California Cancer Registry (57% white, 4% black, 24% Hispanic, and 15% Asian-Pacific Islander [API]). We evaluated effect of race and SES variables on stage of cancer presentation and overall/disease-specific survival. Significant differences in stage of presentation between all racial groups were found (P<.001), with minority groups presenting with a higher percentage of metastatic disease as compared with white patients (black, odds ratio [OR]=1.36 with confidence interval [CI] 1.01-1.84; Hispanic, OR=1.89 [CI, 1.62-2.21], API, OR=1.82 [CI, 1.54-2.15]). Hispanic (OR=1.59, [CI, 1.48-1.72]) and API (OR=1.32 [1.22-1.44]) patients also presented with higher odds of regional disease. Patients with the lowest SES presented with metastatic disease more often than those with the highest SES (OR=1.45 [CI, 1.16-1.82]). Those that were poor/uninsured and/or with Medicaid insurance had higher odds of presenting with metastatic disease as compared with those with private insurance (OR=2.41, [CI, 2.10-2.77]). Unadjusted overall survival rates were higher among API and Hispanic patients and lower among black patients (P<.001 vs white patients). Adjusted overall survival also showed a survival disadvantage for black patients (hazard ratio=1.4, [CI, 1.10-1.73]) and survival advantage for API patients (hazard ratio=0.83, [CI, 0.71-0.97]). In disease-specific survival analyses, when only those patients with metastatic disease were analyzed separately, black patients again had the lowest survival rates, and Hispanic/API patients had the highest survival rates (P<.04). Black patients and those with low SES have worse outcomes for thyroid cancer. API and Hispanic patients may have a protective effect on survival despite presenting with more advanced disease.