Parathyroid Carcinoma: A National Cancer Database Analysis

Introduction: Parathyroid carcinoma is a rare diagnosis. The association of clinical and pathologic factors as well as treatment on overall survival (OS) is not well established. Methods: A retrospective review of patients with parathyroid carcinoma was performed using the National Cancer Database for patients diagnosed from 2004 through 2017. Clin-ical and demographic variables were assessed. A Cox proportional hazards model was used to assess for factors associated with survival. OS rates were determined for 5 and 10 y. Results: Data for 1057 patients were analyzed. The mean age at diagnosis was 57.5 y (standard deviation [SD] 14.0), and 542 (51.3%) were male. The median tumor size was 2.7 cm (inter -quartile range 2.0-3.7 cm). For the extent of surgery, 38 (3.6%) had no surgery, 568 (53.7%) had incomplete resection, 359 (34.0%) had complete resection, 58 (5.5%) had radical resection, and 34 (3.2%) did not have specified and were not used in the Cox proportional hazard regression model. For the cohort, 488 (46.2%) had lymph nodes resected with a mean of 5.5 (SD 6.6) removed. Of these, 32 (8.3%) had nodal metastases with one to six positive nodes. For adju-vant therapy, 159 (15.0%) had external beam radiation with a mean dose of 5463 cGy (SD 1464). Overall, 214 patients died (21.55%), and the estimated 5-and 10-y OS were 82.9% and 57.0%, respectively. In a Cox proportional hazard regression model, age at diagnosis as a continuous variable with hazard ratio (HR) 1.04, 95% confidence interval (CI) 1.01-1.06, P = 0.003, and extent of surgery as a categorical variable with no surgery as the referent group: incomplete surgery HR 0.05, 95% CI 0.01-0.19, P < 0.001; complete surgery HR 0.04, 95% CI 0.01-0.19, P < 0.001; radical surgery HR 0.10, 95% CI 0.02-0.45, P < 0.001; and tumor size as a continuous variable was not associated with OS with an HR of 1.00, 95% CI 0.99-1.00, P = 0.738. Conclusions: Patient age and extent of surgery are modestly associated with survival for para-thyroid carcinoma but not patient sex, nodal metastases, or adjuvant therapy in this cohort.(c) 2022 Elsevier Inc. All rights reserved.

Automated summary

This study retrospectively analyzed data from 1057 patients with parathyroid carcinoma and found that age at diagnosis and extent of surgery are modestly associated with survival, while patient sex, nodal metastases, and adjuvant therapy are not associated with survival in this cohort.