The purpose of this study is to compare how subjects feel after receiving injections of two different types of GnRH six months apart. One injection is given under the skin of the abdomen, and the other one into the muscle of the buttock or thigh.

GnRH is given as an injection. Injections of GnRH can be uncomfortable, causing a feeling of burning or stinging. The uncomfortable feeling may be caused by differences in the types of GnRH and the site of the injection (under the skin of the abdomen, or into the muscle of the buttock or thigh).

Inclusion Criteria:

• Male patients with a diagnosis of advanced prostate cancer for whom treatment with triptorelin pamoate or leuprolide acetate is indicated;
• At least 18 years of age;
• Life expectancy of at least 1 year;
• Capable of completing the study questionnaires without assistance.

Exclusion Criteria:

• Patients for whom treatment with triptorelin pamoate or leuprolide acetate is contraindicated;
• Known hypersensitivity to triptorelin, leuprolide or any other GnRH or luteinizing hormone releasing hormone (LHRH) agonists, or GnRH or LHRH;
• Clinically significant systemic disease or condition that would, in the investigator's opinion, lead to undue risk following administration of either triptorelin or leuprolide;
• History of alcohol/drug abuse within the past year;
• History of significant medical problems that may confound the outcome of this study;
• Requires concomitant medications that may affect study assessments (e.g., topical medications used for pretreatment of injection site pain);
• Participated in another investigational drug study within 30 days
• Judged by the investigator to be unsuitable for enrollment in this study for any reason