Clinical presentation and survival outcomes of well‐differentiated thyroid cancer in Filipinos

BACKGROUND: Filipinos have higher recurrence rates compared to other racial/ethnic groups, which might suggest a higher propensity for aggressive disease. The goal of this study was to perform a population‐based analysis of disease extent at diagnosis and survival outcomes in Filipino patients with well‐differentiated thyroid cancer relative to other racial/ethnic groups. METHODS: The study cohort comprised adult patients with well‐differentiated thyroid cancer diagnosed between 2004 and 2015, identified in the California Cancer Registry. Rates of extrathyroidal extension, nodal metastasis, and distant metastasis were compared between Filipinos, Non‐Filipino Asians, and Non‐Asians using multilevel logistic regression models. Survival outcomes were compared using Cox regression models, utilizing a sequential modeling approach. RESULTS: Filipino ethnicity was associated with extrathyroidal extension (OR 1.35, 95% CI 1.11–1.63) compared with non‐Asians and non‐Filipino Asians. Filipino ethnicity was also associated with nodal metastasis (OR 1.32, 95% CI 1.18–1.46), and with worse OS (Hazard Ratio [HR] 1.45, 95% CI 1.20–1.75) and DSS (HR 1.51, 95% CI 1.12–2.04). After adjusting for demographic and clinical factors, Filipino ethnicity was no longer associated with OS (HR 1.03, 95% CI 0.84–1.25) or DSS (HR 0.93, 95% CI 0.68–1.28). CONCLUSION: Filipino patients with thyroid cancer are more likely to present with locoregionally advanced disease compared with non‐Filipino Asians and non‐Asians. Furthermore, Filipino patients have worse survival outcomes compared with non‐Filipino Asians and non‐Asians. However, this appears to be driven by the higher rates of locoregionally advanced disease in Filipino patients.