Testosterone in Castration-Resistant Prostate Cancer

Inclusion Criteria:

* Patients must have a history of histologically or cytologically confirmed adenocarcinoma of the prostate.
* Patients must have had a history of a response to medical or surgical castration therapy for prostate cancer with a serum PSA nadir of \</= 0.2 ng/ml and must not have had any known subsequent rise in serum PSA level of any magnitude above this nadir within the first 24 months of hormonal therapy. Nadir PSA value following hormonal therapy in combination with non-hormonal therapy such as radical prostatectomy, radiation therapy or chemotherapy do not count towards eligibility.
* Patients must have current evidence of progressive castration-resistant disease that is asymptomatic. Progressive disease is defined by a) radiological evidence of progression: any increase of \> 25% in the products of diameters or 30% in maximum diameter of any measurable lesion; or appearance of an unequivocally new lesion OR b) two consecutive rises in serum PSA of any magnitude measured at least 2 weeks apart, to a level above 2 ng/ml.
* Patients must have a minimum serum PSA level of 1 ng/ml.
* Patients may have palpable disease or radiological evidence of metastatic disease but without the following high-risk features: lymphangitic lung disease on chest X-ray or CT scan; bilateral hydronephrosis related to prostate cancer, palpable disease in the prostate, known brain metastases or suspicion of impending spinal cord or nerve root compression.
* Patients must have a documented castrate level of testosterone (\</= 50ng/ml). For patients who are medically castrated, luteinizing hormone releasing hormone analog will continue. The purpose is to simplify and harmonize exogenous testosterone therapeutics.
* Patients on anti-androgens should be discontinued from such therapy for at least 4 weeks (for bicalutamide for at least 6 weeks), prior to initiation of testosterone therapy and must have had documented progression of disease as in #3.
* Patients must satisfy the following laboratory criteria: serum total bilirubin \< 2 \* institutional upper limit of normal (ULN) and serum aspartate aminotransferase (AST or SGOT) and alanine aminotransferase (ALT or SGPT) \</= 2.5 \* institutional ULN.
* The Eastern Cooperative Oncology Group (ECOG) performance status 0-3.
* Ability to understand and the willingness to sign a written informed consent document.

Exclusion Criteria:

* Small cell or sarcomatoid prostate cancers are not eligible.
* No prior chemotherapy for CRPC.
* Patients may not be receiving any other investigational agents or hormonal therapy besides that specified in the study.
* Uncontrolled angina, severe uncontrolled ventricular arrhythmias, or electrocardiographic evidence of acute ischemia.
* Uncontrolled intercurrent illness including, but not limited to, ongoing or active infections defined as requiring IV antibiotics on day 1 of treatment or psychiatric illness/social situations that would limit compliance with study requirements.
* Unwilling or unable because of comorbid conditions to tolerate intramuscular injections of testosterone every 2 weeks.
* Overt psychosis, mental disability or otherwise incompetent to give informed consent or history of non-compliance.