ES02PARATHYROID SURGERY. A TRUE MARRIAGE OF SKILL, TECHNOLOGY AND SCIENCE

Parathyroid cancer has hitherto been regarded as an exceedingly rare tumour. Most surgeons have never seen a case, nor is it classified as a separate entity on many Cancer registries. Diagnosis has been difficult with few clear histological criteria. It has also been difficult to manage as, if not completely resected progressive, potentially fatal, hypercalcaemia is likely to ensue. The aim of this study was to examine the current incidence and management of parathyroid cancer. This is a retrospective cohort study with data obtained from the University of Sydney Endocrine Surgical Unit database from 1959 to 2008. Over the first four decades, only two cases were ever diagnosed (0.5 cases/ decade), however the last decade has seen 22 cases treated (40X increase - p < 0.001). This is only partly explained by the increase in parathyroid surgery overall (259 cases/ decade in the first period vs. 2,335 cases in the last decade - a 9X increase). In half the recently diagnosed cases, a confident diagnosis was facilitated by parafibromin and PGP9.5 immunohistochemistry, or a family history of hyperparathyroidism jaw-tumour syndrome (HPJT). In all the recent cases long-term normocalcaemia has been achieved with surgical excision and/or calcimimetic therapy (Cinacalcet). The increased incidence of parathyroid cancer is probably due to a number of factors including the increase in parathyroid surgery associated with the minimally invasive approaches, improvements in histopathological criteria, and recognition of familial disease. The availability of calcimimetics has enabled hypercalcaemia to be appropriately managed in the long-term. [PUBLICATION ABSTRACT]