December 06 Newsletter Articles

PHASE II STUDY OF POMEGRANATE JUICE FOR MEN WITH RISING PROSTATE-SPECIFIC ANTIGEN FOLLOWING SURGERY OR RADIATION FOR PROSTATE CANCER

Pantuck AJ, Leppert JT, Zomorodian N, Aronson W, Hong J, et al

Clin Cancer Res 12: 4018-26, 2006 (July)

Purpose: Phytochemicals in plants may have cancer preventive benefits through antioxidation and via gene-nutrient interactions. We sought to determine the effects of pomegranate juice (a major source of antioxidants) consumption on prostate-specific antigen (PSA) progression in men with a rising PSA following primary therapy.

Experimental Design: A phase II, Simon two-stage clinical trial for men with rising PSA after surgery or radiotherapy was conducted. Eligible patients had a detectable PSA >0.2 and <5 ng/mL and Gleason score < 7. Patients were treated with 8 ounces of pomegranate juice daily (Wonderful variety, 570 mg total polyphenol gallic acid equivalents) until disease progression. Clinical end points included safety and effect on serum PSA, serum-induced proliferation and apoptosis of LNCaP cells, serum lipid peroxidation, and serum nitric oxide levels.

Results: The study was fully accrued after efficacy criteria were met. There were no serious adverse events reported and the treatment was well tolerated. Mean PSA doubling time significantly increased with treatment from a mean of 15 months at baseline to 54 months posttreatment (P < 0.001). In vitro assays comparing pretreatment and posttreatment patient serum on the growth of LNCaP showed a 12% decrease in cell proliferation and a 17% increase in apoptosis (P = 0.0048 and 0.0004, respectively), a 23% increase in serum nitric oxide (P = 0.0085), and significant (P < 0.02) reductions in oxidative state and sensitivity to oxidation of serum lipids after versus before pomegranate juice consumption.

Conclusions: We report the first clinical trial of pomegranate juice in patients with prostate cancer. The statistically significant prolongation of PSA doubling time, coupled with corresponding laboratory effects on prostate cancer in vitro cell proliferation and apoptosis as well as oxidative stress, warrant further testing in a placebo-controlled study.

ADOPTION OF A PLANT-BASED DIET BY PATIENTS WITH RECURRENT PROSTATE CANCER

JY Nguyen, JM Major, CJ Knott, KM Freeman, TM Downs, and GA Saxe

Integr Cancer Ther 5: 214-23, 2006 (September)

The Western diet has been associated with prostate cancer incidence as well as risk of disease progression after treatment. Conversely, plant-based diets have been associated with decreased risks. A pilot clinical trial of a 6-month dietary change and stress reduction intervention for asymptomatic, hormonally untreated patients experiencing a consistently rising PSA level, the first sign of recurrence of prostate cancer after surgery or radiation therapy, was conducted to investigate the level of intake of plantbased foods and the relationship between intake and the change in the rate of PSA rise. A pre-post design was employed in which each patient served as his own control. In this multifaceted intervention, patients and their spouses were encouraged to adopt and maintain a plant-based diet.

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Rotating-shift work tied to prostate cancer risk

NEW YORK (Reuters Health) -- The results of a study published in the American Journal of Epidemiology suggest there is a significant association between rotating-shift work and prostate cancer.

"Shift workers are known to be a high-risk population
for...some cancers," such as breast cancer and colorectal
cancer Dr. Tatsuhiko, of the University of Occupational and Environmental Health, Kitakyushu. Japan, and colleagues write. The researchers looked for a link between shift work and the incidence of _prostate cancer among 14,052 male workers enrolled in the Japan Collaborative Cohort Study for Evaluation of Cancer Risk. A survey on lifestyle factors was conducted between 1998 and 1990.

The subjects were asked what their most common work schedule was: day work, rotating-shift work or night work. Overall, 11,269 (80.2 percent) were day workers, 982 (7.0 percent) were night workers, and 1801 (12.8 percent) worked a rotating-shift. Thirty-one cases of prostate cancer were reported over an average follow-up period of 8 years. When the data were adjusted for the effect of age, the researchers noted a three-fold increase in the risk of prostate cancer among the rotating-shift workers. A slight increase was also observed among the night workers.

These results were not significantly altered by further adjusting the date to account for other possible risk factors including _family history of cancer, body mass index, smoking, alcohol consumption job type, physical activity at work perceived stress educational level and mar"4status.

Kubo's team suggests that reduced secretion of the hormone melatonin may be involved, since it helps induce sleep and has anticancer effects. Because this is the first time that shift work has been identified as a risk factor for prostate cancer, they add that the "association needs to be replicated and confirmed in other settings.'

American Journal of Epidemiology, Sep. 2006.

The prestudy rate of PSA rise (from the time of posttreatment recurrence to the start of the study) was ascertained by review of patients' medical records. Dietary assessments were performed and prostate-specific antigen (PSA) levels ascertained at baseline, prior to the start of intervention, and at 3 and 6 months. Changes in numbers of servings of plant-based food groups were calculated and compared with rates of PSA rise over the corresponding time intervals. Median intake of whole grains increased from 1.7 servings/d at baseline to 6.9 and 5.0 servings/d at 3 and 6 months, respectively. Median intake of vegetables increased from 2.8 servings/d at baseline to 5.0 and 4.8 servings/d at 3 and 6 months, respectively. The rate of PSA rise decreased when comparing the prestudy period (0.059) to the period from 0 to 3 months (-0.002, P < .01) and increased slightly, though not significantly, when comparing the period from 0 to 3 months to the period from 3 to 6 months (0.029, P .4316). These results provide preliminary evidence that adoption of a plant-based diet is possible to achieve as well as to maintain for several months in patients with recurrent prostate cancer. Changes in the rate of rise in PSA, an indicator of disease progression, were in the opposite direction as changes in the intake of plant-based food groups, raising the provocative possibility that PSA may have inversely tracked intake of these foods and suggesting that adoption of a plant-based diet may have therapeutic potential in the management of this condition.