Extreme toxicity

To determine whether, in this patient population, treatment with calcitriol and Naproxen is more effective in delaying the growth of prostate cancer than treatment with calcitriol alone as seen in historical controls.

In summary, in vitro and in vivo studies, as well as early phase clinical trial, have shown a promising role for both calcitriol and NSAIDs in the treatment of prostate cancer. Moreover, calcitriol and NSAIDs both exert their antiproliferative effect by decreasing prostaglandin levels, but they do so by different mechanisms. Thus, there is reason to believe that their combined effects on prostaglandins may be synergistic. Preliminary in vitro assays in which calcitriol is given in combination with one of two different NSAIDs (Naprosyn or sulindac) to LNCaP cell lines have indicated such synergy. This observation provides the rational for using them in combination for the treatment of prostate cancer. In addition, it is hoped that any synergy noted would allow for the use of lower doses of NSAIDs.

Inclusion Criteria:

• Must give written informed consent
• Histologically confirmed adenocarcinoma of the prostate
• Biochemical relapse after primary radiation therapy or surgery
• Normal testosterone levels
• 3 rising PSA after nadir, with interval between PSA determinations > 2 weeks

Exclusion Criteria:

• Local recurrence by CT scan
• Distant metastases by bone scan
• Hypercalcemia
• Nephrolithiasis
• Renal insufficiency (serum creatinine > 1.8 mg/dl)
• Pancreatitis
• History of ulcer or gastrointestinal bleeding
• More than 6 months of hormone ablation therapy
• Concurrent therapy for prostate cancer
• Uncontrolled HTN
• H/O MI, CVA, TIA
• Known coronary disease/cerebrovascular disease
• Platelet counts <50
• Patients on anticoagulants
• Patients on lithium