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.