[Secondary hyperparathyroidism in advanced prostate cancer]

Abstract

Background and objective: High parathyroid hormone (PTH) concentrations are associated with increased bone resorption and bone matrix degradation. Some studies show elevated PTH concentrations and hypocalcemia in patients with advanced prostate carcinoma, although the pathophysiological significance of these findings is not well defined.

Materials and methods: We performed a retrospective study of 60 patients diagnosed with advanced prostate cancer (44 nonmetastatic and 16 metastatic) treated with androgen deprivation. In all patients, PTH, calcium, phosphorus, 25 (OH) vitamin D and prostate-specific antigen (PSA) were determined. Bone scintigraphy had previously been performed.

Results: In patients with bone metastases, mean concentrations were as follows: calcium 9.19 mg/dl, phosphorus 3.47 mg/dl, 25 (OH) vitamin D 13.85 ng/ml, PTH 66.8 pg/ml and total PSA 101.27 ng/ml. For those without bone metastases, the results were calcium 9.39 mg/dl, phosphorus 3.38 mg/dl, 25 (OH) vitamin D 20.50 ng/ml, PTH 52.23 pg/ml and total PSA 2.52 ng/ml. PTH levels were significantly higher in patients with prostate cancer and bone metastases than in those without metastases (p=0.03). Vitamin D levels were also significantly lower in this group (p=0.03). There were no differences in other values.

Conclusions: The present study found increased PTH concentrations in patients with advanced prostate cancer. This finding could be useful to predict disease progression.