Hurthle cell carcinoma: a population-level analysis of 3311 patients.

BACKGROUND: Hurthle cell carcinoma (HCC) is an uncommon and more aggressive thyroid cancer. To date, there is a paucity of data at a population level. In this study, demographic, clinical, and pathologic characteristics of HCC were investigated and compared with other types of differentiated thyroid cancers (ODTCs). The authors also evaluated disease-specific survival and compliance with American Thyroid Association (ATA) management guidelines from 2009.

METHODS: The Surveillance, Epidemiology, and End Results (SEER) database from 1988 to 2009 was used to obtain data on patients with thyroid cancer. Data analyses were performed using chi-square tests, analysis of variance, Kaplan-Meier analysis, binary logistic regression, and Cox proportional hazards regression.

RESULTS: In total, 3311 patients with HCC and 59,585 patients with ODTC were identified. Compared with ODTC, HCC was more common among men (31.1% vs 23.0% for ODTC; P < .001) and among older patients (mean age, 57.6 years vs 48.9 years for ODTC; P < .001). Patients with HCC presented with higher SEER disease stage (P < .001), and their tumors were larger (36.1 mm vs 20.2 mm for ODTC; P < .001). Fewer patients underwent total thyroidectomy (P = .028). Both overall and disease-specific survival were lower for patients with HCC (P < .001), and neither improved over the last 2 decades (P = .689). After adjustment, age ≥45 years, not undergoing surgery, and metastatic disease were strongly associated with a worse prognosis (hazard ratio >3.0). Compliance with recommended surgical treatment according to ATA guidelines was lower among patients with HCC aged ≥65 years (odds ratio [OR], 1.43; P = .002) and among unmarried patients (OR, 1.29; P = .004). Predictors of noncompliance with ATA guidelines for treatment with radioactive implants or radioisotopes were age ≥65 years (OR, 1.31; P = .017), diagnosis between 1988 and 1997, no surgery, and partial thyroidectomy (OR, 1.81, 19.48, and 4.02, respectively; P < .001).

CONCLUSIONS: HCC has more aggressive behavior and compromised survival compared with ODTC. The current results indicated that it may be important to consider a different staging system or separate practice guidelines.