Open AccessPrognostic Role of Serum Parathyroid Hormone Levels in Advanced Prostate Cancer Patients Undergoing Zoledronic Acid Administration
Author(s) -
Berruti Alfredo,
Cook Richard,
Saad Fred,
Buttigliero Consuelo,
Lipton Allan,
Tampellini Marco,
Lee KerAi,
Coleman Robert E.,
Smith Matthew R.
Publication year - 2012
Publication title -
the oncologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.176
H-Index - 164
eISSN - 1549-490X
pISSN - 1083-7159
DOI - 10.1634/theoncologist.2011-0448
Subject(s) - medicine , zoledronic acid , prostate cancer , hazard ratio , parathyroid hormone , placebo , urology , bone remodeling , gastroenterology , oncology , cancer , endocrinology , confidence interval , pathology , calcium , alternative medicine
Background. Secondary hyperparathyroidism is frequent in prostate cancer patients with bone metastases, and this condition is worsened by the administration of potent bisphosphonates. Serum parathyroid hormone (PTH) elevation can impair the efficacy of these drugs in terms of survival. Methods. The prognostic role of elevated serum PTH levels at baseline and after 3 months of zoledronic acid administration was assessed prospectively in 643 bone metastatic prostate cancer patients enrolled in a prospective randomized, placebo‐controlled study. Results. On multivariate analysis, after adjusting for major prognostic factors and bone turnover markers, elevated baseline serum PTH level was negatively associated with overall survival (hazard ratio [HR], 1.448; 95% confidence interval [CI], 1.045–2.006; p < .03) in zoledronic acid–treated patients but not in placebo‐treated patients. In patients with normal baseline PTH levels, there was a trend but insignificant association between zoledronic acid administration and a better survival outcome than with placebo (HR, 0.81; 95% CI, 0.65–1.01; p = .065), whereas a trend in the opposite direction was observed in patients with elevated PTH levels (HR, 1.45; 95% CI, 0.87–2.39; p = .151); interaction test, p = .040. Elevated serum PTH level after 3 months of zoledronic acid treatment was not significantly associated with survival outcome. Conclusions. Secondary hyperparathyroidism has a negative prognostic impact in metastatic prostate cancer patients undergoing zoledronic acid administration. Counteracting elevated PTH levels by adequate doses of vitamin D may improve the efficacy of this drug.