Parathyroid carcinoma: a 22-year experience.

PURPOSE: Because parathyroid carcinoma is rare, clear consensus is not available regarding the optimal management of patients with this condition. Treatment strategies generally derive from clinical and anecdotal experiences. We report our experience with this entity.

METHODS: We included all patients with parathyroid carcinoma seen at The University of Texas M. D. Anderson Cancer Center since January 1, 1980. The medical records and pathology specimens were reviewed and verified in all cases.

RESULTS: Since 1980, 27 patients (16 men and 11 women) registered at M. D. Anderson Cancer Center with parathyroid carcinoma and a minimum follow-up of 2 years. The age at initial diagnosis (mean +/- SD) was 46.7 +/- 15.3 years. All patients were seen with hypercalcemia (mean calcium, 13.4 +/- 1.5 mg/dL). Eighteen patients had locally invasive disease, eight had localized disease, and one had distant metastasis. Parathyroid cancer was treated with complete surgical excision with curative intent in 18 patients. In the other nine patients, who had clinical and/or radiographic evidence of soft tissue extension, the tumor was treated by comprehensive "en bloc" soft tissue resection. Of six patients who received adjuvant radiotherapy after initial surgery, only one had a local relapse. In contrast, of 20 patients who did not receive adjuvant radiotherapy, 10 had a local relapse, excluding the one patient who had distant metastases. The 5-year survival was 85%, and the 10-year survival was 77%. Five patients died of parathyroid carcinoma; all deaths were hypercalcemia related.

CONCLUSIONS: Parathyroid carcinoma can be an indolent disease with morbidity and mortality related to hypercalcemia. Adjuvant radiotherapy may improve local control and limit the occurrence of local relapse. A comprehensive multidisciplinary approach with surgery, radiation therapy, and medical treatment for hypercalcemia is needed to optimize patient outcome.