calcitriol and dexamethasone in treating patients with prostate cancer who have undergone surgery or radiation therapy

Conditions: Prostate Cancer

Summary: rationale: calcitriol may help tumor cells develop into normal cells. dexamethasone may increase the effectiveness of calcitriol by making tumor cells more sensitive to the drug. purpose: phase ii trial to study the effectiveness of combining calcitriol with dexamethasone in treating patients with prostate cancer who have undergone surgery or radiation therapy.

objectives: * determine whether calcitriol and dexamethasone can slow the rise in prostate-specific antigen (psa) levels in patients with early, recurrent prostate cancer after prior radical prostatectomy or radiotherapy. * determine the safety of this regimen in these patients. * determine the utility of serum psa in monitoring the therapeutic effect of calcitriol in these patients. outline: patients are stratified according to prior therapy (radical prostatectomy vs radiotherapy). patients receive oral calcitriol once daily on days 1-3 alone on week 1. beginning on week 3, patients receive calcitriol as in week 1 and oral dexamethasone on days 0-4. courses repeat every 2 weeks in the absence of disease progression or unacceptable toxicity. projected accrual: a total of 56 patients (28 per stratum) will be accrued for this study.

Eligibility criteria:
disease characteristics: * histologically confirmed adenocarcinoma of the prostate meeting all of the following criteria: * curatively treated with radical prostatectomy or definitive radiotherapy * no signs of clinical recurrence or dissemination of prostate cancer by digital rectal examination without tumor * no local recurrence by ct scan or mri of the pelvis * no metastases by bone scan and chest x-ray note: prior prostascint scans allowed regardless of results * at least 3 prostate-specific antigen (psa) measurements obtained over at least 90 days after radical prostatectomy on post-radiotherapy psa nadir must be available * psa at least 2 ng/ml after prostatectomy or at least 4 ng/ml after prior radiotherapy * patients previously treated with radiotherapy must have a psa clearly rising from lowest value within 6 months after completion of therapy patient characteristics: age * 18 and over performance status * ecog 0-1 life expectancy * at least 12 months hematopoietic * platelet count at least 100,000/mm\^3 * hemoglobin at least 10 g/dl hepatic * bilirubin no greater than upper limit of normal (uln) * alkaline phosphatase no greater than 2 times uln renal * creatinine less than 1.8 mg/dl * phosphorus normal * no hypercalcemia (albumin-corrected calcium greater than uln) * no nephrolithiasis * single episode of renal lithiasis allowed provided episode occurred more than 5 years prior to study other * fertile patients must use effective double-barrier contraception for at least 1 week before, during, and for at least 2 weeks after study * no symptomatic pancreatitis * no uncontrolled diabetes * no known or suspected inability to comply with study requirements (e.g., abuse of alcohol/drugs or psychotic states) * curatively treated condition associated with renal stones (e.g., hyperparathyroidism, bladder dysfunction, or obstructive uropathy) allowed provided patient has been free of stone formation for more than 5 years prior concurrent therapy: biologic therapy * not specified chemotherapy * no prior chemotherapy for prostate cancer * at least 24 months since prior chemotherapy for other diseases endocrine therapy * more than 6 months since prior hormonal therapy, including neoadjuvant or adjuvant androgen deprivation therapy (e.g., luteinizing hormone-releasing hormone analogue or antiandrogen) * no prior androgen deprivation therapy of more than 8 months duration * no prior hormonal therapy for prostate cancer more than 3 months after definitive local therapy * no concurrent androgen therapy radiotherapy * see disease characteristics * more than 3 months since prior radiotherapy for locally recurrent prostate cancer * no concurrent radiotherapy, including for pain control surgery * see disease characteristics other * more than 4 weeks since prior investigational drugs * no concurrent medication known to affect systemic calcium metabolism, including any of the following: * more than 400 iu of cholecalciferol supplements * more than 500 iu of vitamin a supplements * calcium supplements * fluoride * antiepileptics

Keywords: adenocarcinoma of the prostate recurrent prostate cancer