DISEASE CHARACTERISTICS: Histologically proven adenocarcinoma of the prostate Previously treated with radical prostatectomy at least 3 months ago HLA-A2 positive PSA greater than 0.5 ng/mL and rising At least 0.3 ng/mL greater than post-prostatectomy nadir Confirmed by at least 2 additional PSA levels at least 2 weeks apart No bone metastases by bone scan within past 3 months No clinical evidence of local disease recurrence (no palpable mass or induration in prostatic fossa)

PATIENT CHARACTERISTICS: Age: Over 18 Performance status: ECOG 0-1 OR Karnofsky 70-100% Life expectancy: More than 1 year Hematopoietic: WBC at least 3,000/mm3 Hepatic: Bilirubin normal AST and ALT no greater than 2.5 times upper limit of normal Renal: Creatinine normal Cardiovascular: No symptomatic congestive heart failure No unstable angina pectoris No cardiac arrhythmia Other: Fertile patients must use effective contraception HIV negative No clinical immune dysfunction illness (e.g., rheumatoid arthritis) No ongoing or active infection No other concurrent uncontrolled illness that would preclude study No concurrent psychiatric illness or social situation that would preclude study

PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: No prior chemotherapy Endocrine therapy: Neoadjuvant hormonal therapy prior to prostatectomy allowed No concurrent hormonal therapy for recurrent prostate cancer Radiotherapy: No prior radiotherapy to the prostate No prior radiotherapy to the pelvis Surgery: See Disease Characteristics Other: No other concurrent investigational agents No concurrent commercial agents intended to treat the malignancy No concurrent immunosuppressive therapy