Study to Evaluate the Safety and Efficacy of Switching From Zoladex® Monthly or Quarterly, to Eligard® Semiannual.

Inclusion Criteria: 1. Patient able to understand the process of the informed consent form (ICF); 2. Male aged ≥18 years old; 3. Having a histologically confirmed diagnosis of prostate adenocarcinoma; 4. Having an indication of androgen deprivation treatment: 1. Being on treatment with monthly or quarterly goserelin acetate depot formulation for at least 3 months and for a maximum of 18 months OR; 2. Having an indication to start treatment with quarterly goserelin acetate depot formulation. 5. Patient with ECOG (Eastern Cooperative Oncology Group) performance status 0 to 2; 6. Patient with appropriate castration level, defined by a serum testosterone level ≤50 ng/dL (≤1.73 nmol/L) demonstrated before V1. 7. Appropriate hematologic function in the screening period: neutrophil count \>1,500/μL, platelets \>100,000/μL, hemoglobin \>10 g/dL; 8. Appropriate liver function in the screening period of the study: total serum bilirubin ≤1.5 x upper normal limit, AST (aspartate aminotransferase) or ALT (alanine aminotransferase) ≤40 U/L, alkaline phosphatase \<130 U/L, gamma-GT (glutamyl transferase) \<100 U/L; 9. Appropriate kidney function in the screening period of the study: serum urea within normal limits for the method used at the institution, serum creatinine between 0.6 and 1.3 mg/dL, creatinine clearance calculated by the Cockroft- Gault formula \> 40 mL/min; Exclusion Criteria: 1. Patients who did not have or do not have an indication for treatment with goserelin acetate; 2. Patients with goserelin treatment for over 18 months; 3. Patients who have received previous chemotherapy; 4. Patient unable to follow the foreseen study visit schedule; 5. Suspected or proven brain metastasis or active leptomeningeal disease; 6. Uncontrolled arterial hypertension defined as systolic pressure ≥160 mmHg or diastolic pressure ≥95 mmHg; 7. Long-term use of estrogen therapy or peripheral blockade; 8. Another concomitant neoplasm; 9. Any medical condition which, at the investigator's discretion, offers risk to the patient's participation in the study; 10. Having participated in another clinical study within less than 12 months.