Can cinacalcet replace parathyroid intervention in severe secondary hyperparathyroidism?

A 6-month observational study was conducted in 61 patients (33 men and 28 women, mean age 54.8 +/- 12.4 years) treated with cinacalcet in whom parathyroid intervention was indicated. Thirty-seven patients had baseline intact parathyroid hormone (iPTH) levels of >500 pg/mL, but only five still had levels this high after 6-month cinacalcet therapy. No patients had phosphorus (P), calcium (Ca), or iPTH levels within the target range at baseline, but six patients (9.8%) reached all three target ranges after treatment. The stratum with many patients who had 2-4 enlarged parathyroid glands shifted toward the low PTH groups (iPTH < 300 pg/mL) with treatment. There was less of a tendency for patients with more enlarged glands, that is, 10 mm or larger at baseline, to have a higher PTH level after cinacalcet treatment. There was no significant difference in the total volume of parathyroid glands after treatment, since some glands enlarged while others shrank. These findings indicate cinacalcet to be a potentially useful treatment. Our results suggest that 80% of cases indicated for parathyroid intervention could avoid such interventional therapies with cinacalcet administration. However, the variability in the gland-shrinking effect of cinacalcet on parathyroid glands merits further study.