Parathyroid Carcinoma: A 43-Year Outcome and Survival Analysis

Context: Parathyroid carcinoma is a rare but ominous cause of primary hyperparathyroidism. Objectives and Main Outcome Measures: The objective of the study was to review the outcomes of parathyroid cancer patients and to evaluate the factors associated with mortality. Design, Setting, and Patients: This was a retrospective review performed on 37 patients with parathyroid cancer treated at a single university tertiary care center between 1966 and 2009. Results: The average age at cancer diagnosis was 53 yr (range 23-75 yr), and 23 patients (62%) were men. Eighteen patients (49%) recurred after their initial cancer operation. The average number of neck dissections done for cancer was three (range 1-11). After initial diagnosis, 22 patients (60%) eventually developed complications, including unilateral (n = 11) or bilateral (n = 3) vocal cord paralysis (38%). Eight patients (22%) had, at some point, an associated benign parathyroid adenoma. Median overall survival was 14.3 yr (range 10.5-25.7 yr) from the date of diagnosis. Factors associated with increased mortality included lymph node or distant metastases, number of recurrences, higher calcium level at recurrence, and a high number of calcium-lowering medications. Factors not associated with mortality included age, race, tumor size, time to first recurrence, and extent of initial operation. Initial operations done at our center had improved survival (P = 0.037) and decreased complication rates (P < 0.001) vs. those done elsewhere. Conclusion: Parathyroid cancer patients typically have a long survival, which often includes multiple reoperations for recurrence and thus a high rate of surgical complications. Patients in whom there is a high index of suspicion for parathyroid cancer should be referred to a dedicated endocrine surgery center for their initial operation. (J Clin Endocrinol Metab 96: 3679-3686, 2011)