Factors associated with late recurrence after parathyroidectomy for primary hyperparathyroidism

A recent study with unusually lengthy follow-up after surgery for primary hyperparathyroidism reported higher recurrence rates than previously appreciated. We sought to identify specific factors associated with late recurrence after seemingly curative parathyroidectomy.

Prospectively collected data were retrieved for patients who had surgical treatment of sporadic primary hyperparathyroidism with ≥ 3-year follow-up (3-17.6 years). Recurrence was defined by 6 months of eucalcemia with subsequent hypercalcemia and a high or unsuppressed parathyroid hormone. Recurrent patients were compared with cured patients (defined by consistent eucalcemia).

Among 261 patients, 28 (10.7%) had recurrence and 233 (89.3%) were cured. The mean time to recurrence was 77 months (range 13-170). The mean final intraoperative parathyroid hormone (49.0 pg/mL vs 37.5 pg/mL, P < .01), 6-month calcium levels (9.6 mg/dL vs 9.2 mg/dL, P = .02) and mean 6-month parathyroid hormone levels (86.5 pg/mL vs 59.6 pg/mL, P = .04) were higher for recurrence. By multivariable analysis, 6-month calcium ≥ 9.7 and eucalcemic elevation of the parathyroid hormone at 6 months were independently associated with recurrent primary hyperparathyroidism.

Long-term follow-up after apparent curative surgery for primary hyperparathyroidism identified a high late recurrence rate (10.7%), up to 17 years later. A 6-month calcium >9.7 mg/dL and eucalcemic parathyroid hormone elevation at 6 months may be associated with recurrence, and such findings may help guide management.