The aim of this phase IV interventional study is to evaluate variation in bone mineral density and lean and fat body composition in patients with prostate cancer without bone metastasis, treated with Degarelix. These variations are evaluated at time 0 (before starting androgen deprivation therapy with Degarelix) and after 12 months of therapy by dual-energy X-ray absorptiometry (DXA scan).

Gonadotropin-releasing hormone (GnRH) agonists decrease bone mineral density (BMD) and increase fracture risk in men with prostate carcinoma. GnRH agonists also increase fat mass and decrease lean body mass. These treatment-related changes in body composition may contribute to fatigue, emotional distress, and decreased quality of life. Whereas the consequences of initial GnRH agonist on BMD and body composition are well characterized, less is known regarding the effects of GnRH antagonists. At the best of our knowledge the changes in body composition induced by Degarelix in prostate cancer patients has never been explored. Dual-energy X-ray absorptiometry (DXA) is a reliable and accurate method to determine the changes in body composition in patients with prostate cancer (PCa) undergoing androgen deprivation therapy (ADT).

The change in body composition is a major determinant of increased morbidity and mortality induced by ADT and DXA provides the most precise measure of body composition. This study is designed to obtain explorative information on changes in bone mineral density, fat body mass and lean body mass by DXA scan after administration of Degarelix. These preliminary data compared with historical data of patients submitted to GnRH agonists could provide a rationale for a subsequent prospective randomized clinical trial.

Inclusion Criteria:

• male outpatients, aged 18 or older, willing and able to provide written informed consent;
• histological diagnosis of prostate carcinoma;
• more than 6-month survival prospect;
• no bone metastases as assessed by bone scintigraphy;
• eligibility to ADT with Degarelix in the opinion of the clinical investigator.

Exclusion Criteria:

• patients with absolute or relative contraindication for prescription of Degarelix. In particular:
• hypersensitivity towards any component of Firmagon®
• patients who receive concomitant medications that might prolong the QT interval, in particular class I A (such as quinidine, procainamide, disopyramide,) or class III antiarrhythmics (such as amiodarone, sotalol, dofetilide, ibutilide)
• patients with history of or risk factors for Torsades de Pointes
• patients who take either methadone or moxifloxacin or antipsychotic
• patients with alteration in electrolyte blood levels (such as sodium, potassium, calcium and magnesium)
• patients with severe kidney and/or liver dysfunctions;
• concomitant bone metabolic disease, such as Paget's disease, primary hyperparathyroidism or chronic hypercortisolism, as recorded by medical history;
• renal failure (baseline serum creatinine more than 1.5 mg/dl);
• prior hormonal treatment;
• prior or concomitant treatment with bisphosphonates or other drugs known to affect bone metabolism (for example steroids, calcitonin);
• patients participating in an interventional clinical trial in which any treatment or follow-up is mandated;