Studies
Prostate Cancer and Pomegranate Juice
A study that began in 2003 is starting to yield important information when it comes to treating men who have undergone standard treatment for prostate cancer. The findings of the study were recently presented at the 104th Annual Scientific Meeting of the American Urological Association.1
The presentation described the trial that included 48 men 60+ years old who underwent radiation therapy or surgery to treat localized prostate cancer. After treatment, the men in the study all had escalating prostate-specific antigen (PSA) levels. Men who fail initial prostate cancer treatment show a progressive PSA elevation.
A six-year follow-up of the men who drank eight ounces of pomegranate juice a day revealed that those who continued drinking the juice had lower PSA levels than those who quit drinking the juice and were no longer in the trial.2
Jon Finkel
Higher Vitamin E Levels Predict Improved Prostate Cancer Survival
An article in Cancer Research reported improved prostate cancer survival among men with high vitamin E levels.*
Participants in the ATBC study whose vitamin E levels were among the top fifth of participants were found to have a 33% lower risk of dying of prostate cancer compared to those whose levels were in the lowest fifth. Men who received vitamin E supplements in the trial and whose levels of vitamin E were highest experienced the lowest risk of prostate cancer mortality, which was 49% less than that of subjects with the lowest vitamin E levels.
When all-cause mortality was analyzed among those with prostate cancer, participants in the top fifth of serum vitamin E levels were shown to have a 33% lower risk of death over the course of follow-up, suggesting “a possible effect for alpha-tocopherol on other causes of death in men with prostate cancer.”
Dayna Dye
For some prostate tumors, ‘watchful waiting’ seems safe
Men diagnosed with early, low-risk prostate cancer face a choice about treatment. Some tumors will not grow larger, but other tumors will progress, making them candidates for surgery, radiation, or chemotherapy. A new clinical trial shows that men with low-risk prostate cancer who decided to defer treatment for almost eight years did no worse than similar men who decided to have treatment sooner.
A team from Beth Israel Deaconess Medical Center, Brigham and Women’s Hospital, and the University of California, San Francisco, analyzed medical records of more than 51,000 men enrolled in the Health Professionals Follow-up Study. Among the 3,331 men who were diagnosed with prostate cancer between 1986 and 2007, there were 342 men with low-risk tumors who chose not to have treatment in the first year. Half of those men still had not had treatment almost eight years after diagnosis.
There were few deaths from prostate cancer among the men who deferred treatment. Two percent of the men who deferred treatment died compared with 1 percent of the men with low-risk cancers who had treatment right away, a difference that was not statistically significant.
“I think it really brings some reassurance to the notion that it can be safe to defer treatment for the very low risk subset of prostate cancers,’’ said senior author Dr. Martin Sanda of Beth Israel Deaconess.
Active surveillance of patients based on prostate specific antigen screenings, repeated biopsies, and imaging tests can be used to track whether cancer is progressing, he said.
BOTTOM LINE: Men with low-risk prostate cancer who deferred treatment for a year or more fared no worse after eight years than men who chose early treatment.
CAUTIONS: The number of men who deferred treatment is small, so drawing conclusions about them should be done with caution. Patients were not randomly assigned to the waiting or immediate-treatment groups, so unknown differences among the men in the two groups might have biased the outcomes.
WHERE TO FIND IT: Journal of Clinical Oncology, Aug. 31
ELIZABETH COONEY
Selenium intake may worsen prostate cancer in some, study reports
BOSTON--Higher selenium levels in the blood may worsen prostate cancer in some men who already have the disease, according to a study by researchers at Dana-Farber Cancer Institute the University of California, San Francisco.
A higher risk of more-aggressive prostate cancer was seen in men with a certain genetic variant found in about 75 percent of the prostate cancer patients in the study. In those subjects, having a high level of selenium in the blood was associated with a two-fold greater risk of poorer outcomes than men with the lowest amounts of selenium. By contrast, the 25 percent of men with a different variant of the same gene and who had high selenium levels were at 40 percent lower risk of aggressive disease. The variants are slightly different forms of a gene that instructs cells to make manganese superoxide dismutase (SOD2), an enzyme that protects the body against harmful oxygen compounds.
The research findings suggest that "if you already have prostate cancer, it may be a bad thing to take selenium," says Philip Kantoff, MD, director of Dana-Farber's Lank Center for Genitourinary Oncology and senior author of the study that is published by the Journal of Clinical Oncology on its website now and later will be in a print journal. The lead author is June Chan, ScD, of the University of California, San Francisco.
The unexpected results are the first to raise concern about this potentially harmful consequence of taking supplemental selenium. Kantoff says, "These findings are interesting particularly in light of the recent negative results from the SELECT prevention study, which asked if selenium could protect against prostate cancer."
The new study reveals the strong interaction between selenium and SOD2 to influence the biology of prostate cancer, a finding that these investigators had shown in a previous study. The authors say the current research demonstrated that variations in the make up of the SOD2 gene dramatically alter the effects of selenium on the risk of aggressive prostate cancer.
Selenium is a mineral found widely in rocks and dirt. Small amounts of selenium are essential for health: 40 to 70 micrograms is the recommended daily intake. In recent years, supplemental selenium has been sold and promoted as a means of preventing prostate cancer, largely based on observational studies that found higher risk of prostate cancer incidence and mortality in areas of the country that are naturally low in selenium.
However, research aimed at confirming the benefits of selenium supplementation have been mixed. Recently, the SELECT study, which involved 35,000 men, was halted early when, after more than five years, it showed that the supplements didnt affect the incidence of prostate cancer.
Previous studies had found that the risk of developing prostate cancer was modified by a strong interaction between SOD2 and selenium. The new research was designed to look at the effect of this interaction on men already diagnosed with prostate cancer.
Scientists examined banked blood samples, DNA, and medical records of 489 male Dana-Farber patients diagnosed between 1994 and 2001 with localized or locally advanced prostate cancer. Their mean age was 62, and their mean PSA (prostate-specific antigen) measurement was 6.0 ng/mL. About half the men were assessed as having a good disease risk, one-third had an intermediate risk, and the remaining one-sixth were at poor risk. The researchers measured the level of selenium in the blood and, using the stored DNA, they determined the SOD2 genotype -- the specific form of the SOD2 gene carried by each patient.
Simply having a high level of selenium was associated with a slightly elevated risk of aggressive prostate cancer. But the risk was much more strongly affected by the interaction of selenium levels and whether the patient had a certain variant of the SOD2 gene. Men with the highest selenium levels and the "AA" form of the SOD2 gene were 40 percent less likely to have been diagnosed with aggressive prostate cancer than the men with same gene form but low levels of selenium.
But for men carrying the "V" form of the gene, selenium had the opposite effect. In these men, those with the highest levels of selenium in their blood were about twice as likely to have an aggressive type of prostate cancer as their counterparts with low selenium levels, says Kantoff, who is also a professor of medicine at Harvard Medical School.
The study couldnt determine whether any of the men had been taking selenium supplements or not. But the researchers noted that men in the large SELECT prevention trial had a much higher average selenium level than those in the current study. "Among the 25 percent of men with the AA genotype, having greater selenium levels may protect against aggressive disease," the authors concluded. "However, for the 75 percent of men who carry a V allele, higher selenium levels might increase the likelihood of having worse characteristics."
Therefore, they add, it is important to know which type of SOD2 gene a man has when considering the risks and potential benefits of taking selenium supplements. Additionally, the authors say the effects of the interaction between the SOD2 genotype and selenium may help explain apparently conflicting results of previous studies.
The results may seem counterintuitive to the public, who have been told for years that antioxidants can help people live longer, healthier lives with a lowered risk of cancer. However, Kantoff says, "There is some precedent to this research has suggested that antioxidants could be protective if you dont have cancer, but once you do, then antioxidants may be a bad thing."
In addition to Kantoff and Chan, other authors of the paper include William Oh, MD, Wanling Xie, PhD, Meredith Regan, ScD, and Miyako Abe, PhD, of Dana-Farber; Meir J. Stampfer DrPH, MD, of Brigham and Women's Hospital and the Harvard School of Public Health, and Irena King, PhD, of the Fred Hutchinson Cancer Research Center, Seattle.
The work was supported by grants from the National Cancer Institute and several foundations and charitable organizations.
Dana-Farber Cancer Institute (www.dana-farber.org) is a principal teaching affiliate of the Harvard Medical School and is among the leading cancer research and care centers in the United States. It is a founding member of the Dana-Farber/Harvard Cancer Center (DF/HCC), designated a comprehensive cancer center by the National Cancer Institute.
Green Tea Slows Prostate Cancer
Active compounds in green tea may slow the progression of prostate cancer, according to a new study published in Cancer Prevention Research.
The study, which was conducted at Louisiana State University, also showed that green tea might lower the incidence of prostate cancer in the first place.
The study is one of the few green tea trials that evaluated biomarkers in order to predict prostate cancer's progression, said study leader James A. Cardelli, director of basic and translational research in the Feist-Weiller Cancer Center at LSU University Health Sciences Center-Shreveport.
The biomarkers tracked were PSA (prostate specific antigen), HGF (hepatocyte growth factor), and VEGF (vascular endothelial growth factor).
The study, which used compounds of green tea polyphenols in the form of Polyphon E provided by Polyphenon Pharma, involved 26 men ages 41 to 72 who were scheduled for radical prostactectomies. For an average of about 35 days up until the day before surgery, each man took four capsules of Polyphenon E, which was equal to drinking 12 cups of normally brewed green tea.
The researchers found that the green tea compounds significantly reduced serum levels of PSA, HGF, and VEGF, with reductions as great as 30 percent in some patients.
There were few side effects, and other biomarkers were "positively affected," Cardelli said.
Referring to the LSU study and to a year-long clinical trial in Italy involving green tea polyphenols, Cardelli said, "These studies are just the beginning and a lot of work remains to be done. However, we think that the use of tea polyphenols alone or in combination with other compounds currently used for cancer therapy should be explored as an approach to prevent cancer progression and recurrence."
Selenium intake may worsen prostate cancer in some, study reports
BOSTON--Higher selenium levels in the blood may worsen prostate cancer in some men who already have the disease, according to a study by researchers at Dana-Farber Cancer Institute the University of California, San Francisco.
A higher risk of more-aggressive prostate cancer was seen in men with a certain genetic variant found in about 75 percent of the prostate cancer patients in the study. In those subjects, having a high level of selenium in the blood was associated with a two-fold greater risk of poorer outcomes than men with the lowest amounts of selenium. By contrast, the 25 percent of men with a different variant of the same gene and who had high selenium levels were at 40 percent lower risk of aggressive disease. The variants are slightly different forms of a gene that instructs cells to make manganese superoxide dismutase (SOD2), an enzyme that protects the body against harmful oxygen compounds.
The research findings suggest that "if you already have prostate cancer, it may be a bad thing to take selenium," says Philip Kantoff, MD, director of Dana-Farber's Lank Center for Genitourinary Oncology and senior author of the study that is published by the Journal of Clinical Oncology on its website now and later will be in a print journal. The lead author is June Chan, ScD, of the University of California, San Francisco.
The unexpected results are the first to raise concern about this potentially harmful consequence of taking supplemental selenium. Kantoff says, "These findings are interesting particularly in light of the recent negative results from the SELECT prevention study, which asked if selenium could protect against prostate cancer."
The new study reveals the strong interaction between selenium and SOD2 to influence the biology of prostate cancer, a finding that these investigators had shown in a previous study. The authors say the current research demonstrated that variations in the make up of the SOD2 gene dramatically alter the effects of selenium on the risk of aggressive prostate cancer.
Selenium is a mineral found widely in rocks and dirt. Small amounts of selenium are essential for health: 40 to 70 micrograms is the recommended daily intake. In recent years, supplemental selenium has been sold and promoted as a means of preventing prostate cancer, largely based on observational studies that found higher risk of prostate cancer incidence and mortality in areas of the country that are naturally low in selenium.
However, research aimed at confirming the benefits of selenium supplementation have been mixed. Recently, the SELECT study, which involved 35,000 men, was halted early when, after more than five years, it showed that the supplements didn’t affect the incidence of prostate cancer.
Previous studies had found that the risk of developing prostate cancer was modified by a strong interaction between SOD2 and selenium. The new research was designed to look at the effect of this interaction on men already diagnosed with prostate cancer.
Scientists examined banked blood samples, DNA, and medical records of 489 male Dana-Farber patients diagnosed between 1994 and 2001 with localized or locally advanced prostate cancer. Their mean age was 62, and their mean PSA (prostate-specific antigen) measurement was 6.0 ng/mL. About half the men were assessed as having a good disease risk, one-third had an intermediate risk, and the remaining one-sixth were at poor risk. The researchers measured the level of selenium in the blood and, using the stored DNA, they determined the SOD2 genotype -- the specific form of the SOD2 gene carried by each patient.
Simply having a high level of selenium was associated with a slightly elevated risk of aggressive prostate cancer. But the risk was much more strongly affected by the interaction of selenium levels and whether the patient had a certain variant of the SOD2 gene. Men with the highest selenium levels and the "AA" form of the SOD2 gene were 40 percent less likely to have been diagnosed with aggressive prostate cancer than the men with same gene form but low levels of selenium.
But for men carrying the "V" form of the gene, selenium had the opposite effect. In these men, those with the highest levels of selenium in their blood were about twice as likely to have an aggressive type of prostate cancer as their counterparts with low selenium levels, says Kantoff, who is also a professor of medicine at Harvard Medical School.
The study couldn’t determine whether any of the men had been taking selenium supplements or not. But the researchers noted that men in the large SELECT prevention trial had a much higher average selenium level than those in the current study. "Among the 25 percent of men with the AA genotype, having greater selenium levels may protect against aggressive disease," the authors concluded. "However, for the 75 percent of men who carry a V allele, higher selenium levels might increase the likelihood of having worse characteristics."
Therefore, they add, it is important to know which type of SOD2 gene a man has when considering the risks and potential benefits of taking selenium supplements. Additionally, the authors say the effects of the interaction between the SOD2 genotype and selenium may help explain apparently conflicting results of previous studies.
The results may seem counterintuitive to the public, who have been told for years that antioxidants can help people live longer, healthier lives with a lowered risk of cancer. However, Kantoff says, "There is some precedent to this – research has suggested that antioxidants could be protective if you don’t have cancer, but once you do, then antioxidants may be a bad thing."
In addition to Kantoff and Chan, other authors of the paper include William Oh, MD, Wanling Xie, PhD, Meredith Regan, ScD, and Miyako Abe, PhD, of Dana-Farber; Meir J. Stampfer DrPH, MD, of Brigham and Women's Hospital and the Harvard School of Public Health, and Irena King, PhD, of the Fred Hutchinson Cancer Research Center, Seattle.
The work was supported by grants from the National Cancer Institute and several foundations and charitable organizations.
Dana-Farber Cancer Institute (www.dana-farber.org) is a principal teaching affiliate of the Harvard Medical School and is among the leading cancer research and care centers in the United States. It is a founding member of the Dana-Farber/Harvard Cancer Center (DF/HCC), designated a comprehensive cancer center by the National Cancer Institute.
Fish Consumption Improves Survival in Prostate Cancer
Men who consume large amounts of fish have better survival from prostate cancer, according to a long-term follow-up study.*
More than 20,000 men who participated in the Physician’s Health Study answered questionnaires at enrollment in 1983 about medical history, lifestyle characteristics, and food intake, and then reported all new illnesses each year thereafter. During follow-up of 19 years, 2,161 cases of prostate cancer occurred and 230 men died of the disease.
Total fish intake was not a significant predictor of developing prostate cancer. However, consumption of fish and of fish-derived omega-3 fatty acids increased the likelihood of surviving prostate cancer. Men who ate fish at least five times per week (versus less than once per week) had a 48% lower risk of death from prostate cancer, and men with the highest fatty acid intake had a 35% lower risk.
The results suggest that fish consumption delays prostate cancer progression.
—Laura J. Ninger, ELS
(From Life Extension, March 2009)
Studies fail to settle prostate testing debate
"Regular screening for prostate cancer may prevent the deaths of a small number of men but exposes many more to potentially needless treatments accompanied by serious complications, according to two landmark studies that fail to settle a long-running debate about the value of screening." » Read More
More Evidence Prostate Tests Overdiagnose Cancer
As many as two of every five men whose prostate cancer was caught through a PSA screening test have tumors too slow-growing to ever be a threat, says a new study that raises more questions about the controversial tests...... » Read More
Pomegranate Juice Keeps Psa Levels Stable
Drinking an eight ounce glass of pomegranate juice daily increased by nearly four times the period during which PSA levels in men treated for prostate cancer remained stable, a three-year UCLA study has observed...... » Read More
New Study: Testosterone Replacement Therapy and Prostate Cancer
For the past 65 years, it has been axiomatic that higher serum testosterone (T) levels cause increased prostate cancer (PCa) growth and that T supplementation carries the risk for converting occult PCa into a clinical PCa..... » Read More
New Study: Two Years of Testosterone Therapy Associated with Decline in Prostate-Specific Antigen in a Man with Untreated
Prostate Cancer
Testosterone (T) therapy has long been considered contraindicated in men with prostate cancer (PCa). However, the traditional view regarding the relationship of T to PCa has come under new scrutiny, with recent reports suggesting that PCa growth may not be greatly affected by variations in serum T within the near-physiologic range..... » Read More
New study on side effects could help men choose a treatment
All prostate cancer treatments involve side effects but new American research may help men choose the best option. In one of the first large studies to examine quality of life after therapy.... » Read More
Vitamin D doesn't cut prostate cancer risk - Yahoo! News
Vitamin D -- the so-called sunshine vitamin -- does not appear to cut a man's risk of getting prostate cancer, researchers said on Tuesday.... » Read More
Improving Diet, Lifestyle Slows Prostate Cancer
Intensive diet and lifestyle changes slow the progression of low-grade prostate cancer, this new research indicates that diet can influence the outcome of established prostate cancer... » Read More
Study Details Effects of Prostate Cancer
One of the first large quality-of-life studies on today's prostate cancer treatments suggests that for some men, it's a matter of picking your poison and facing potential sexual, urinary or other problems..... » Read More
High Lycopene Level Reduces Risk of Advanced Prostate Cancer
A newly published European study indicates taht men with the highest blood levels of lycopene are 60% less likely to develop advanced prostate cancer, compared.... » Read More
Resveratrol Suppresses Prostate Cancer Development
Researchers from the University of Alabama at Birmingham have shown that prostate cancer-prone mice fed resveratrol experience significant protection against development of the disease.1 Found in red wine and some fruits and vegetables, resveratrol is a polyphenol antioxidant.... » Read More
Nonfat milk linked to prostate cancer
The amount of calcium and vitamin D in the diet appears to have little or no impact on the risk of prostate cancer, but the consumption of low-fat or nonfat milk may increase the risk of the malignancy, according to the results of two studies published in the American Journal of Epidemiology.... » Read More
Pectin lnduces Self-Destruction
Pectin lnduces Self-Destruction in Prostate Cancer Cells Pectin, a plant—produced compound used in the preparation of homemade jellies, may protect.... » Read More
Time Course and Predictors of Symptoms after Primary Prostate Cancer Therapy
Purpose: Understanding the distinctive patterns of treatment-related dysfunction after alternative initial treatments for early prostate cancer (PC) may improve patients' choice of treatment and later help them adjust to its consequences.... » Read More
Green tea for a healthy prostate?
New research suggests that phytochemicals in green tea may help prevent the spread of prostate cancer. Since earlier research suggests.... » Read More
Many prostate cancer patients receive improper or 'mismatched' therapies
Prostate cancer patients often receive treatment that is contraindicated by pre-existing conditions, like urinary or bowel dysfunction, according to a new study. Dr. James Talcott of the Massachusetts General Hospital in Boston and co-investigators found that patients with certain pretreatment dysfunctions often receive contraindicated or “mismatched” therapies, which can lead to....
» Read More
Green Tea Shown To Prevent Prostate Cancer
"Numerous earlier studies, including ours, have demonstrated that green tea catechins, or pure EGCG (a major component of GTCs), inhibited cancer cell growth in laboratory models," Bettuzzi explained. "We wanted to conduct a clinical trial to find out whether catechins could prevent cancer in men. The answer clearly is.... » Read More
