A Randomized Study to Investigate the Presence of Tocopherol Metabolites in the Prostate
试验速览
- 阶段
- 1 期
- 状态
- 已完成
- 入组人数
- 65
- 试验地点
- 1
- 主要终点
- Effect of tocopherol supplementation on plasma and urine levels of α-, γ-, and δ-tocopherols, PSA, and prostaglandin E2
研究概览
简要总结
RATIONALE: Vitamin E supplements may stop or delay the development of prostate cancer in patients who are at risk of prostate cancer or who have prostate cancer. It is not yet known which vitamin E regimen is more effective in preventing prostate cancer.
PURPOSE: This randomized phase I trial is comparing vitamin E supplement regimens to see how well they work in preventing cancer in patients at risk of prostate cancer or who have prostate cancer.
详细描述
OBJECTIVES:
- Determine the effect of tocopherol supplementation on plasma and urine levels of α-, γ-, and δ-tocopherols, PSA, and prostaglandin E_2 by comparing the blood and urine samples collected before and after the supplementation in patients with prostate cancer.
- Test the hypothesis that the supplementation reduced oxidative and nitrosative stress by measuring plasma levels of F_2-isoprostane, C-reactive protein, and 3-nitrotyrosine as well as urinary levels of 8-hydroxy-2-deoxyguanosine (8-OHdG).
- Determine the levels of α-, γ-, and δ-tocopherols in prostate tissues and analyze immunohistochemically (IHC) for cell proliferation, apoptosis, cyclooxygenase-2, 8-OHdG, and 3-nitropyrosine levels in prostate cancer/tissue slides.
OUTLINE: Patients are randomized into 1 of 3 arms.
- Arm I: Patients receive no supplementation.
- Arm II: Patients receive oral high γ-tocopherol vitamin E supplementation once daily for 1 week.
- Arm III: Patients receive oral high γ-tocopherol vitamin E supplementation once daily for 2 weeks.
Blood, urine, and tissue samples are collected periodically and analyzed for oxidative/nitrosative stress and other markers (i.e., F2-isoprostane, 8-OHdG, 3-nitrotyrosine, prostaglandin E2, C-reactive protein, and PSA), biomarkers in prostate tumors and nontumorous tissues (i.e., 8-OHdG, 3-nitrotyrosine, and cyclooxygenase-2) by IHC, and pharmacokinetics by high-performance liquid chromatography.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Prevention
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- Male
- 接受健康志愿者
- 否
入选标准
- •DISEASE CHARACTERISTICS:
- •Meets one of the following criteria:
- •Abnormal digital rectal examination or abnormal prostate specific antigen (> 4.0 ng/mL)
- •Obstructing prostate
- •Biopsy-proven prostate cancer
- •Scheduled to undergo prostate surgery (i.e., transurethral prostatectomy or prostatectomy)
- •PATIENT CHARACTERISTICS:
- •No uncontrolled diabetes, uncontrolled blood pressure, chronic congestive heart failure, or history of renal insufficiency
- •No personal or family history of a bleeding disorder
- •No known history of problems absorbing dietary fats (e.g., Crohn's disease, cystic fibrosis)
- •PRIOR CONCURRENT THERAPY:
- •More than 2 weeks since prior NSAIDs or corticosteroids
- •No concurrent supplementation of vitamin E (a multivitamin containing ≤ 60 IU of vitamin E is allowed)
- •No concurrent colestipol or orlistat
- •No concurrent warfarin or dicumarol
排除标准
- 未提供
研究组 & 干预措施
Arm I
Patients receive no supplementation.
干预措施: sham intervention (Procedure)
Arm II
Patients receive oral high γ-tocopherol vitamin E supplementation once daily for 1 week.
干预措施: vitamin E (Dietary Supplement)
Arm III
Patients receive oral high γ-tocopherol vitamin E supplementation once daily for 2 weeks.
干预措施: vitamin E (Dietary Supplement)
结局指标
主要结局
Effect of tocopherol supplementation on plasma and urine levels of α-, γ-, and δ-tocopherols, PSA, and prostaglandin E2
时间窗: 4 years
Oxidative stress and nitrosative stress as assessed by plasma levels of F2-isoprostane, C-reactive protein, and 3-nitrotyrosine as well as urinary levels of 8-hydroxy-2-deoxyguanosine (8-OHdG)
时间窗: 4 years
Levels of α-, γ-, and δ-tocopherols in prostate tissues and cell proliferation, apoptosis, cyclooxygenase-2, 8-OHdG, and 3-nitropyrosine levels as assessed by IHC
时间窗: 4 years
次要结局
未报告次要终点