The general hypothesis put forward in this study is that the degree of cohesion (agreement) in the relationship, or dyadic adjustment affects a patient's quality of life and clinical course during the first few critical months following diagnosis and the introduction of treatment. The level of cohesion in the relationship is certainly not the only parameter associated with changes in the quality of life. Other factors must also be investigated such as level of education, circumstances surrounding the diagnosis (new diagnosis or relapse), management (single therapy or adjuvant therapy), the level of physical activity, the patient's age and the presence of functional disorders, etc.

Inclusion Criteria:

• Patient presenting with histologically confirmed prostate cancer.
• Patient eligible to start GnRH agonist therapy, either as monotherapy or adjuvant therapy, and for whom one of these treatments was selected voluntarily by the urologist, prior to the start of the study.
• Patient currently living with the same partner for at least 6 months.
• Patient and partner capable of reading, understanding and returning an evaluation self-questionnaire 6 months after the initial consultation.
• Patient giving its written consent to participate to the study.

Exclusion Criteria:

• The subject is participating in another clinical trial.
• Patient who has received a GnRH agonist therapy during the last 2 years.

Prostate cancer patients and their partners recruited by urologists.