Researchers in San Francisco have discovered a new virus inside the tumors of some men with prostate cancer, raising the possibility that a viral infection may play a role in that disease as it does in a handful of other cancers.
The virus, a close relative of a microbe known to cause cancer in mice, was spotted by UCSF researchers using the same molecular screening equipment that helped find the SARS virus in 2003.
UCSF researcher Joseph DeRisi, who won a 2004 MacArthur Foundation "genius grant" after his work on the SARS investigation, said he did not expect to see a virus in any of the prostate tumors. "To my amazement, we found it," he said. "And it was a new virus, which was more amazing.''
Although the discovery may be an important break in the long effort to implicate a virus in prostate cancer, this new virus was found only in a small percentage of prostate tumors -- almost exclusively among men who are missing genes that normally help cells fight off viruses.
It will take more studies to determine whether the new virus, dubbed XMRV, plays any role at all in causing prostate cancer, or is merely a microbial bystander found at the tumor site.
As a result of the findings, researchers are developing a blood test to detect antibodies to the XMRV. The test would be used at first only in the laboratory so scientist can learn more about it.
The work was reported on Friday by Dr. Eric Klein, a prostate cancer specialist at the Glickman Urologic Institute of the Cleveland Clinic, during an American Society of Clinical Oncology symposium in San Francisco.
Klein has been hunting a prostate cancer-causing virus for nearly a decade, and 18 months ago began collaborating with DeRisi and his UCSF colleague, Dr. Don Ganem.
"Ten years ago, research suggested that certain genes predispose some men to prostate cancer,'' Klein said.
These men were missing a gene that produced a natural virus-fighting chemical. That suggested to Klein that prostate cancer might be caused by a virus that could exploit this weakness, and the hunt for a culprit was on.
Samples of prostate tumors were run in DeRisi's screening test, which can detect up to 2,000 known plant and animal viruses. After the test found evidence of a virus similar to one that infects mice, the UCSF researchers used additional lab work to fish out a copy of XMRV.
Some viruses have been clearly implicated in cancer. Hepatitis B increases the risk of liver cancer 100 fold. Cervical cancer is caused by infection with the human papilloma virus, which also causes genital warts.
Klein concedes that the evidence for a viral role in prostate cancer is not nearly as strong.
The XMRV virus was found in half of a small group of men with prostate cancer who also inherited from both parents the trait that disables the virus fighting enzyme. Only about 13 percent of males have such a genetic vulnerability.
Still, Klein would like to find out whether the virus infects a much larger portion of the population, and only lingers in those who lack the virus-fighting enzyme. Blood tests for exposure to the virus among prostate cancer sufferers may eventually show whether XMRV could have infected them long ago, possibly causing enough damage to start a slow-growing prostate tumor that shows up years after the virus has been cleared from their systems.
Monday, February 27, 2006
Prostate Cancer Treatment And Bone Loss - Common Osteoporosis Treatment May Help
Men with prostate cancer who experience bone loss from cancer treatment could benefit from a weekly oral therapy commonly given to women with osteoporosis, according to a study presented by the University of Pittsburgh Medical Center (UPMC) at the American Society of Clinical Oncology Prostate Cancer Symposium, Feb. 24 to 26 at the San Francisco Marriott. The study, abstract number 139, will be featured in a press program at the meeting, 7:30 a.m., Sunday, Feb. 26.
"In previous studies, we have determined that men who receive androgen deprivation therapy, a frequently used treatment for prostate cancer, suffer from severe drops in bone mass and are at an increased risk for fracture," said study principal investigator Susan Greenspan, M.D., professor of medicine, University of Pittsburgh and director, Osteoporosis Prevention and Treatment Center, UPMC. "In an attempt to mitigate these effects, we gave men using this therapy a once-weekly oral agent called alendronate that is commonly used to treat osteoporosis. We found that men who received it had significantly increased bone mass compared to those who did not receive the therapy."
The study included 112 men with prostate cancer with an average age of 71. After an average of two years androgen deprivation therapy for prostate cancer, only 9 percent of the men had normal bone mass, while 52 percent had low bone mass and 39 percent developed osteoporosis. To study the effect of alendronate on these men, they were randomized into two groups to receive either alendronate once a week through an orally administered pill or a placebo. At one year follow-up, bone mass in the spine and hip increased significantly in the men treated with alendronate, 4.9 percent and 2.1 percent respectively. By comparison, men in the placebo group had significant losses of bone mass in the spine and hip, 1.3 percent and .7 percent respectively. In addition, the therapy was well-tolerated and easily administered.
"Since most men with prostate cancer remain on androgen deprivation therapy for an indefinite amount of time, bone loss can be a serious and long-term side effect from therapy," said Joel Nelson, M.D., co-author of the study and professor and chairman of the department of urology at the University of Pittsburgh School of Medicine. "With more than 230,000 men being diagnosed with prostate cancer each year, the addition of alendronate therapy could help to prevent the incidence of debilitating bone fractures."
Androgen deprivation therapy works by depriving the body of testosterone, an androgen hormone that increases the growth of prostate tumors. However, testosterone also is essential to maintaining bone mass in men. While doctors have been using this type of therapy for more than a decade to treat men with late-stage metastatic prostate cancer, they have begun using it more recently in men with earlier-stage disease and for longer periods of time; this increased exposure increases the risk for developing osteoporosis.
"These results suggest to us that men who are under treatment for prostate cancer should be encouraged to get a bone density test and that those at risk could benefit greatly from bone-preserving therapy," said Dr. Greenspan.
"In previous studies, we have determined that men who receive androgen deprivation therapy, a frequently used treatment for prostate cancer, suffer from severe drops in bone mass and are at an increased risk for fracture," said study principal investigator Susan Greenspan, M.D., professor of medicine, University of Pittsburgh and director, Osteoporosis Prevention and Treatment Center, UPMC. "In an attempt to mitigate these effects, we gave men using this therapy a once-weekly oral agent called alendronate that is commonly used to treat osteoporosis. We found that men who received it had significantly increased bone mass compared to those who did not receive the therapy."
The study included 112 men with prostate cancer with an average age of 71. After an average of two years androgen deprivation therapy for prostate cancer, only 9 percent of the men had normal bone mass, while 52 percent had low bone mass and 39 percent developed osteoporosis. To study the effect of alendronate on these men, they were randomized into two groups to receive either alendronate once a week through an orally administered pill or a placebo. At one year follow-up, bone mass in the spine and hip increased significantly in the men treated with alendronate, 4.9 percent and 2.1 percent respectively. By comparison, men in the placebo group had significant losses of bone mass in the spine and hip, 1.3 percent and .7 percent respectively. In addition, the therapy was well-tolerated and easily administered.
"Since most men with prostate cancer remain on androgen deprivation therapy for an indefinite amount of time, bone loss can be a serious and long-term side effect from therapy," said Joel Nelson, M.D., co-author of the study and professor and chairman of the department of urology at the University of Pittsburgh School of Medicine. "With more than 230,000 men being diagnosed with prostate cancer each year, the addition of alendronate therapy could help to prevent the incidence of debilitating bone fractures."
Androgen deprivation therapy works by depriving the body of testosterone, an androgen hormone that increases the growth of prostate tumors. However, testosterone also is essential to maintaining bone mass in men. While doctors have been using this type of therapy for more than a decade to treat men with late-stage metastatic prostate cancer, they have begun using it more recently in men with earlier-stage disease and for longer periods of time; this increased exposure increases the risk for developing osteoporosis.
"These results suggest to us that men who are under treatment for prostate cancer should be encouraged to get a bone density test and that those at risk could benefit greatly from bone-preserving therapy," said Dr. Greenspan.
Treatment For Prostate Cancer Helps Older Men Live Longer, Versus Observation
A new study shows older men with early stage prostate cancer survive longer if they are treated versus not being treated in favor of the "watchful waiting" approach advocated by many physicians for older men with other health problems. In addition, the study revealed a survival benefit for men treated with radiation therapy making it the first study to demonstrate a survival advantage in an older population. The study was presented by Fox Chase Cancer Center medical oncologist Yu-Ning Wong, M.D., at the 2006 Prostate Cancer Symposium Feb. 25 in San Francisco.
The study examines survival data of more than 48,606 men between 65 and 80 years old who survived at least one year after a diagnosis of localized prostate cancer (cancer that has not spread beyond the prostate).
Since the advent of the PSA (prostate-specific antigen) blood test about 20 years ago, many more cases of prostate cancer have been diagnosed at earlier stages.
"Some prostate cancers grow so slowly that they never become life-threatening, especially in elderly men who may die of other causes before the cancer causes problems," explained Wong. "But other men develop complications and die from their cancer making the decision to treat quite difficult."
It remains unclear whether detecting early prostate tumors translates into an equivalent benefit of saving lives and whether the benefits of early detection outweigh the risks of complications from follow up diagnostic tests and cancer treatments.
The cases examined in this study were diagnosed between 1991 and 1999. The men ranged from 65 to 80 years old at diagnosis. Median age at diagnosis was 72. A total of 34,046 men received treatment with either radiation therapy (19,948) or surgery--radical prostatectomy--to remove the prostate (14,098). The remaining 14,560 men were only observed (watchful waiting).
More than half the treated men were alive by the end of the study, with a median survival of 13 years. Median survival for the group receiving observation was about 10 years.
"This large, population-based study demonstrates a survival advantage for men treated with either radical prostatectomy or radiation therapy compared to observation," Wong said. "Eligible men should be considered for both treatment options."
The study examines survival data of more than 48,606 men between 65 and 80 years old who survived at least one year after a diagnosis of localized prostate cancer (cancer that has not spread beyond the prostate).
Since the advent of the PSA (prostate-specific antigen) blood test about 20 years ago, many more cases of prostate cancer have been diagnosed at earlier stages.
"Some prostate cancers grow so slowly that they never become life-threatening, especially in elderly men who may die of other causes before the cancer causes problems," explained Wong. "But other men develop complications and die from their cancer making the decision to treat quite difficult."
It remains unclear whether detecting early prostate tumors translates into an equivalent benefit of saving lives and whether the benefits of early detection outweigh the risks of complications from follow up diagnostic tests and cancer treatments.
The cases examined in this study were diagnosed between 1991 and 1999. The men ranged from 65 to 80 years old at diagnosis. Median age at diagnosis was 72. A total of 34,046 men received treatment with either radiation therapy (19,948) or surgery--radical prostatectomy--to remove the prostate (14,098). The remaining 14,560 men were only observed (watchful waiting).
More than half the treated men were alive by the end of the study, with a median survival of 13 years. Median survival for the group receiving observation was about 10 years.
"This large, population-based study demonstrates a survival advantage for men treated with either radical prostatectomy or radiation therapy compared to observation," Wong said. "Eligible men should be considered for both treatment options."
Thursday, February 16, 2006
Vitamin supplements don’t prevent prostate cancer
Taking the vitamins E and C or the nutrient beta-carotene doesn’t protect against prostate cancer, says the latest study in the continuing, confusing quest to determine when supplements really help health.
The government research, published Tuesday in the Journal of the National Cancer Institute, is among many large studies examining whether these antioxidants play a role in prostate cancer when taken as pills - instead of when they’re consumed as part of an overall healthy diet.
The government research, published Tuesday in the Journal of the National Cancer Institute, is among many large studies examining whether these antioxidants play a role in prostate cancer when taken as pills - instead of when they’re consumed as part of an overall healthy diet.
Monday, February 13, 2006
Saw Palmetto Won't Ease Enlarged Prostate
Millions of older American men use the herbal supplement saw palmetto to treat an enlarged prostate, but a new study concludes the product doesn't work.
A few smaller studies had suggested the extract might be of limited benefit to men with enlarged prostate, clinically known as benign prostatic hyperplasia (BPH).
However, this controlled, blinded study of 225 men found that, "over a 12-month period, saw palmetto was no better than placebo in changing symptoms for this condition," said lead researcher Dr. Stephen Bent, an assistant professor of medicine at the University of California, San Francisco.
For more on benign prostatic hyperplasia, head to the U.S. National Institute of Diabetes and Digestive and Kidney Diseases.
Monday, February 06, 2006
High-risk Black Men Least Likely To Get Screening For Prostate Cancer
The men most at risk for aggressive prostate cancer - black men with a family history - are the least likely to get screening even during peak ages of risk, researchers say.
Only 25 percent of black men during peak ages of 60-69 are screened using the common blood test that measures prostate specific antigen levels and 36 percent get annual digital rectal exams, according to a study published in the Feb. 15 issue of Cancer.
Black males are diagnosed with prostate cancer at an average age of 65.
Just under 50 percent of all high-risk black males get blood tests and 38 percent get physical exams. Sixty-five percent of black males without a family history get the blood test and 45 percent get physical exams. By comparison, 81 percent of white males age 60-69 get blood tests and 68 percent get physical exams.
"Healthy black men who have several first-degree relatives with prostate cancer are much less likely to have ever gotten a prostate screening than black men without a family history and white men in the general population," says Dr. Sally Weinrich, a nursing professor and Georgia Cancer Coalition Distinguished Cancer Scholar. "However, these are the men who have a higher-than-average risk because of their positive family histories. Hereditary forms of prostate cancer are usually diagnosed at an earlier age than non-hereditary prostate cancer."
Dr. Weinrich and her husband, Dr. Martin Weinrich, an MCG biostatistician, identified black males with positive family histories through the national African American Hereditary Prostate Cancer Study, funded by the National Institutes of Health and concluded in 2004. Comparable black males and white males were identified through the Centers for Disease Control and Prevention's 1998 and 2000 National Health Interview Surveys.
Prior research has shown that black men have a 50 percent higher incidence of prostate cancer and more than double the mortality rate of white men. This research further suggests a glaring health disparity with access to health care and economics as key factors, Dr. Weinrich says.
"Black men have the right to be informed about prostate cancer screening options," she says. "We need additional research to study the reasons why black men with a positive family history have lower screening rates than black men in general."
Physicians should ask men specific questions about their family history. Men should also ask their families questions about who has had cancer and at what age they were diagnosed, experts say.
"While doctors cannot conclusively diagnose hereditary prostate cancer because no prostate cancer gene has been identified, answers to those questions are critical to our genetic revolution," says Dr. Weinrich.
Scientists are discovering more each day about the disease, she says. "People should also pay attention to the research. Thanks to genetic and scientific knowledge, we know more today about prostate cancer than we did five years ago and we will learn even more in the next five years."
Other co-authors on the study include Dr. Georgia Dunston, Howard University; Dr. Francis Collins, National Human Genome Research Institute; Dr. James Bennett, an Atlanta urologist; and other participants of the African American Hereditary Prostate Cancer Study.
"We at the School of Nursing are pleased that the Weinrichs have such depth in this area of much-needed research," says Dr. Lucy Marion, dean of the MCG School of Nursing. "They have a long history of research for detection of cancer among older African-American men."
Only 25 percent of black men during peak ages of 60-69 are screened using the common blood test that measures prostate specific antigen levels and 36 percent get annual digital rectal exams, according to a study published in the Feb. 15 issue of Cancer.
Black males are diagnosed with prostate cancer at an average age of 65.
Just under 50 percent of all high-risk black males get blood tests and 38 percent get physical exams. Sixty-five percent of black males without a family history get the blood test and 45 percent get physical exams. By comparison, 81 percent of white males age 60-69 get blood tests and 68 percent get physical exams.
"Healthy black men who have several first-degree relatives with prostate cancer are much less likely to have ever gotten a prostate screening than black men without a family history and white men in the general population," says Dr. Sally Weinrich, a nursing professor and Georgia Cancer Coalition Distinguished Cancer Scholar. "However, these are the men who have a higher-than-average risk because of their positive family histories. Hereditary forms of prostate cancer are usually diagnosed at an earlier age than non-hereditary prostate cancer."
Dr. Weinrich and her husband, Dr. Martin Weinrich, an MCG biostatistician, identified black males with positive family histories through the national African American Hereditary Prostate Cancer Study, funded by the National Institutes of Health and concluded in 2004. Comparable black males and white males were identified through the Centers for Disease Control and Prevention's 1998 and 2000 National Health Interview Surveys.
Prior research has shown that black men have a 50 percent higher incidence of prostate cancer and more than double the mortality rate of white men. This research further suggests a glaring health disparity with access to health care and economics as key factors, Dr. Weinrich says.
"Black men have the right to be informed about prostate cancer screening options," she says. "We need additional research to study the reasons why black men with a positive family history have lower screening rates than black men in general."
Physicians should ask men specific questions about their family history. Men should also ask their families questions about who has had cancer and at what age they were diagnosed, experts say.
"While doctors cannot conclusively diagnose hereditary prostate cancer because no prostate cancer gene has been identified, answers to those questions are critical to our genetic revolution," says Dr. Weinrich.
Scientists are discovering more each day about the disease, she says. "People should also pay attention to the research. Thanks to genetic and scientific knowledge, we know more today about prostate cancer than we did five years ago and we will learn even more in the next five years."
Other co-authors on the study include Dr. Georgia Dunston, Howard University; Dr. Francis Collins, National Human Genome Research Institute; Dr. James Bennett, an Atlanta urologist; and other participants of the African American Hereditary Prostate Cancer Study.
"We at the School of Nursing are pleased that the Weinrichs have such depth in this area of much-needed research," says Dr. Lucy Marion, dean of the MCG School of Nursing. "They have a long history of research for detection of cancer among older African-American men."
Thursday, February 02, 2006
Better Prostate Cancer Detection
BACKGROUND: According to the American Cancer Society, more than 232,000 men in the United States will be diagnosed with prostate cancer this year. More than 30,300 men will die from the disease. While one man in six will get prostate cancer during his lifetime, only one man in 34 will die from it. If a man is suspected of having prostate cancer with an abnormal PSA test or by a digital rectal exam, doctors will then do a transrectal ultrasound-guided biopsy (TRUS). A TRUS biopsy - which is the current standard - removes a few samples of the prostate to determine whether cancer is present.
CAN YOU TRUST THE TRUS?
Gary Onik, M.D., the Director of Florida Hospital/Celebration Health's Prostate Cancer Research Program, says, "Unfortunately, we're finding that [the TRUS biopsy] is really not very effective at all. When you look at the statistics of a normal size gland ... the chances of actually finding that tumor are about 15 percent. So, 85 percent of patients by that biopsy method may be missing their cancer." You might be asking -- how can this possibly be the gold standard? Dr. Onik says, "Because we didn’t have any other way of knowing that we were doing it incorrectly." Now, there is a new, much more reliable way to get an accurate diagnosis.
3D MAPPING
A new biopsy method, called 3D mapping, uses a grid placed over the prostate to determine exactly how much cancer there is and exactly where it is in the prostate. Dr. Onik explains, "It's like playing Battleship with the prostate. Every hole that we have has a coordinate, and we can place the needle through that. We have a picture that overlays and shows us the prostate and where that biopsy's being taken from. Then, we can basically look at the picture when we get a positive biopsy back and see exactly where the cancer is in the gland.” In a TRUS biopsy, the samples are taken through the rectum, so doctors can only get about 12 samples. With the new 3D mapping method, biopsies are taken through the skin so doctors are able to get many more -- even up to 100 -- samples. By getting so many more samples, doctors can determine how widespread the cancer is. If only one or two samples out of 100 come back with a slight percentage of cancer, it could be a much different prognosis and treatment regimen than if half of the samples came back showing significant cancer.
BENEFITS FOR PATIENTS
Dr. Onik says, "A lot of patients are being treated inappropriately with the wrong therapies because they’re either under-diagnosed or over-diagnosed." He says many men who choose watchful waiting as a therapy may be doing so with a very inaccurate diagnosis. He says, "When we biopsy them [with 3D mapping], we find that a lot of them have very significant cancer that needs to be treated but wouldn’t have been treated unless we had done this biopsy." On the other hand, Dr. Onik says some men may get an inaccurate or incomplete diagnosis with a TRUS biopsy and decide to have a radical prostatectomy. He says, "Sometimes, we see patients who are ready to have their prostate gland and everything removed, and we do this [3D mapping] biopsy, and we can’t even find their tumor."
WHERE IS IT?
Currently, Dr. Onik says there are about five centers in Florida doing the 3D mapping biopsy method. More studies are planned, and Dr. Onik expects that this method will become widespread across the country within a few years. He adds, "This is one of those times where I think this will possibly change the way we look at prostate cancer."
FOR MORE INFORMATION
http://www.hopeforprostatecancer.com/
CAN YOU TRUST THE TRUS?
Gary Onik, M.D., the Director of Florida Hospital/Celebration Health's Prostate Cancer Research Program, says, "Unfortunately, we're finding that [the TRUS biopsy] is really not very effective at all. When you look at the statistics of a normal size gland ... the chances of actually finding that tumor are about 15 percent. So, 85 percent of patients by that biopsy method may be missing their cancer." You might be asking -- how can this possibly be the gold standard? Dr. Onik says, "Because we didn’t have any other way of knowing that we were doing it incorrectly." Now, there is a new, much more reliable way to get an accurate diagnosis.
3D MAPPING
A new biopsy method, called 3D mapping, uses a grid placed over the prostate to determine exactly how much cancer there is and exactly where it is in the prostate. Dr. Onik explains, "It's like playing Battleship with the prostate. Every hole that we have has a coordinate, and we can place the needle through that. We have a picture that overlays and shows us the prostate and where that biopsy's being taken from. Then, we can basically look at the picture when we get a positive biopsy back and see exactly where the cancer is in the gland.” In a TRUS biopsy, the samples are taken through the rectum, so doctors can only get about 12 samples. With the new 3D mapping method, biopsies are taken through the skin so doctors are able to get many more -- even up to 100 -- samples. By getting so many more samples, doctors can determine how widespread the cancer is. If only one or two samples out of 100 come back with a slight percentage of cancer, it could be a much different prognosis and treatment regimen than if half of the samples came back showing significant cancer.
BENEFITS FOR PATIENTS
Dr. Onik says, "A lot of patients are being treated inappropriately with the wrong therapies because they’re either under-diagnosed or over-diagnosed." He says many men who choose watchful waiting as a therapy may be doing so with a very inaccurate diagnosis. He says, "When we biopsy them [with 3D mapping], we find that a lot of them have very significant cancer that needs to be treated but wouldn’t have been treated unless we had done this biopsy." On the other hand, Dr. Onik says some men may get an inaccurate or incomplete diagnosis with a TRUS biopsy and decide to have a radical prostatectomy. He says, "Sometimes, we see patients who are ready to have their prostate gland and everything removed, and we do this [3D mapping] biopsy, and we can’t even find their tumor."
WHERE IS IT?
Currently, Dr. Onik says there are about five centers in Florida doing the 3D mapping biopsy method. More studies are planned, and Dr. Onik expects that this method will become widespread across the country within a few years. He adds, "This is one of those times where I think this will possibly change the way we look at prostate cancer."
FOR MORE INFORMATION
http://www.hopeforprostatecancer.com/
Waistline Protection for the Prostate
New studies claim prostate cancer can be predicted by a man's waist size
Highlight:
Registered dietitian Karen Collins looks at recent studies that have suggested waist size is an effective predictor of prostate cancer.
Highlight:
Registered dietitian Karen Collins looks at recent studies that have suggested waist size is an effective predictor of prostate cancer.
In one of the new studies that show the risk from excessive body fat, among men treated for prostate cancer, those who had gained more than about three-and-a-half pounds a year between the ages of 25 and 40 were twice as likely to have this cancer recur as men who gained less weight. According to this study, men who were obese when diagnosed with prostate cancer were more likely to have the cancer return than leaner men. The impact on recurrence was even stronger if they were obese by age 40.
Original source:
http://www.infozine.com/news/stories/op/storiesView/sid/12085/
Fatty Acid: Link to Prostate Cancer?
Prostate cancer tumors may get a growth spurt from omega-6 fatty acids, scientists report in Cancer Research.
In lab tests, researchers exposed human prostate cancer cells to arachidonic acid, a common type of omega-6 fatty acid. Those cells grew about twice as quickly as prostate cancer cells not exposed to arachidonic acid.
Full article here.
In lab tests, researchers exposed human prostate cancer cells to arachidonic acid, a common type of omega-6 fatty acid. Those cells grew about twice as quickly as prostate cancer cells not exposed to arachidonic acid.
Full article here.
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