Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically confirmed adenocarcinoma of the prostate

- Underwent prior radical prostatectomy as local definitive therapy for prostate cancer

- Meets criteria for 1 of the following strata:

- Has received ≥ 9 months of androgen blockade therapy (either single-agent
luteinizing hormone-releasing hormone or combined androgen blockade) for
serologic progression after surgery

- Serologic progression defined as a rising prostate-specific antigen, which
has risen serially on two determinations (from baseline) ≥ 1 week apart,
and no objective evidence of metastatic disease

- Prior radiotherapy for serologic progression allowed

- Did not receive any form of androgen blockade therapy within the past 9 months

- No metastatic disease by abdominal/pelvic CT scan and whole-body scan

PATIENT CHARACTERISTICS:

- Able to tolerate CT scanning in the supine position

- No prior medical condition known to have effects on the thymus, including myasthenia
gravis, lymphoma, hyperthyroidism, or cachexia

- No autoimmune disorders

- No acute illness, including active infection requiring antibiotics

PRIOR CONCURRENT THERAPY:

- See Disease Characteristics

- No prior systemic chemotherapy

- No prior immunological therapy

- No prior single-agent antiandrogen (e.g., high-dose bicalutamide)

- No prior or concurrent 5-alpha reductase inhibitors (e.g., finasteride), PC-SPES, or
estrogen-containing nutraceuticals

- No concurrent systemic steroid therapy (topical steroids allowed)