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.