Parathyroid carcinoma in more than 1,000 patients: A population-level analysis.

BACKGROUND: Parathyroid carcinoma (PC) is a rare malignancy with a moderate prognosis. The staging system, prognostic indicators, and optimal surgical management are still under debate. This large cohort explores prognostic factors for PC. METHODS: 1,022 cases of PC in the 1998-2011 National Cancer Data Base that underwent surgery were examined for predictors of lower overall survival (OS) and relative risk (RR) of death at 5 years. RESULTS: The 5-year OS was 81.1% in 528 patients with ≥ 60 months of follow-up. The overall cohort was mainly non-Hispanic (96.5%), white (77.4%), and insured (94.3%), with a median age of 57 years. Mean OS was lower and RR of death greater in older (P < .001), black (P = .007) patients with a secondary malignancy (P = .015) and ≥ 2 comorbidities (P = .005), whose surgical specimen had positive surgical margins (P = .026) or positive lymph nodes (P < .001). Multivariate cox regression demonstrated that positive lymph nodes (hazard ratio [HR], 6.47; 95% CI, 1.81-23.11) and older age (HR, 2.35; 95% CI, 1.25-4.43) were associated with lower OS. CONCLUSION: PC is a rare malignancy with a 5-year OS of 81.1%. Positive lymph nodes and older age predict lower OS and an increased risk of death.