Oct 26, 2010
The Wall Street Journal Health Blog: "The United States Preventive Services
Task Force has canceled a meeting set for early next month at which the
thorny issue of prostate-cancer screening was due for a vote. ... [W]hen
prostate-cancer screening came up last fall, the USPSTF initially voted to
recommend against screening for men of all ages before opting instead to
re-vote on the issue. . Currently the USPSTF has an 'I' rating for
prostate-cancer screening, which means the current evidence is insufficient
to assess the balance of benefits and harms, for men younger than 75. For
older men, the rating is 'D,' which means the USPSTF recommends against
screening. The group last issued recommendations in August 2008, but in
2009, results from two large screening trials were published. The studies
provided no clear answer of whether the benefits of screening outweighed the
harms" (Hobson, 10/26).
This is part of Kaiser Health News' Daily Report - a summary of health
policy coverage from more than 300 news organizations. The full summary of
the day's news can be found here and you can sign up for e-mail
subscriptions to the Daily Report here. In addition, our staff of reporters
and correspondents file original stories each day, which you can find on our
home page.
Tuesday, October 26, 2010
Monday, October 25, 2010
Important New PSA Research
MONDAY, Oct. 25 (HealthDay News) -- Having a prostate-specific antigen (PSA) test to screen for prostate cancer reduces the risk that if cancer develops it will spread to other parts of the body, new research indicates.
The finding adds to the ongoing debate on whether PSA screenings actually improve survival rates or, by contrast, lead to unnecessary treatment.
"Our study shows that routine screening not only improves the patient's quality of life by stopping metastatic disease, but it also decreases the burden of care for this advanced disease that must be provided by the health-care system," study author Chandana Reddy, a senior biostatistician at the Cleveland Clinic in Ohio, said in a news release from the American Society for Radiation Oncology.
"This demonstrates that the PSA test is extremely valuable in catching the disease earlier and allowing men to live more productive lives after treatment," Reddy said.
Reddy and his colleagues are to report their findings Monday at the American Society for Radiation Oncology annual meeting, in San Diego.
PSA tests are blood tests that have been available and widely used since 1993. They measure levels of the prostate-specific antigen protein produced by the prostate; high levels are thought to be an indication of prostate cancer.
However, critics have cautioned that some patients diagnosed with early prostate cancer are subjected to aggressive treatments -- and their unwelcome side effects, such as incontinence and erectile dysfunction -- for a disease that is often slow-moving and of no real consequence to survival if left untreated among older patients who are likely to die of other, unrelated causes.
However, the researchers pointed out that prostate cancer is not curable when it is caught late and has spread (or metastasized) to other parts of the body. They suggested that assessing to what degree a PSA diagnosis might reduce the risk of metastasis could be the best way to determine the value of the test.
To that end, Reddy and his team analyzed data on more than 1,700 prostate cancer patients who between 1986 and 1996 had been treated with either radiation therapy or surgery to take out their prostate gland and the surrounding tissue.
Noting that in the first half of the study period, PSA tests were not yet available, the authors compared the spread of the disease over the course of 10 years among those who had been diagnosed with a PSA test and those who had not.
Over the 10-year period, metastatic disease took hold among 13 percent of all the patients. However the researchers found that regardless of whether patients were categorized as having high-, medium-, or low-risk disease, those who had been diagnosed as a result of a PSA screening were significantly less likely than those who weren't to have seen their cancer spread during the decade following their original treatment.
Dr. Lionel L. Banez, an assistant professor of urologic surgery at Duke University Medical Center, said that the current study leans toward the relative benefits of prostate cancer screening.
"There is compelling evidence that PSA testing saves lives, especially when performed in an optimized strategy," he said. "For example, getting an initial PSA measurement at age 40 to properly assess baseline prostate cancer risk has been proven to be quite beneficial.
Nevertheless, Banez acknowledged that doctors need to interpret test results judiciously.
"The challenge," he stressed, "lies in ensuring that the risks for over-diagnosis and over-treatment, as well as potential decline in quality of life, are minimized or avoided."
More
The finding adds to the ongoing debate on whether PSA screenings actually improve survival rates or, by contrast, lead to unnecessary treatment.
"Our study shows that routine screening not only improves the patient's quality of life by stopping metastatic disease, but it also decreases the burden of care for this advanced disease that must be provided by the health-care system," study author Chandana Reddy, a senior biostatistician at the Cleveland Clinic in Ohio, said in a news release from the American Society for Radiation Oncology.
"This demonstrates that the PSA test is extremely valuable in catching the disease earlier and allowing men to live more productive lives after treatment," Reddy said.
Reddy and his colleagues are to report their findings Monday at the American Society for Radiation Oncology annual meeting, in San Diego.
PSA tests are blood tests that have been available and widely used since 1993. They measure levels of the prostate-specific antigen protein produced by the prostate; high levels are thought to be an indication of prostate cancer.
However, critics have cautioned that some patients diagnosed with early prostate cancer are subjected to aggressive treatments -- and their unwelcome side effects, such as incontinence and erectile dysfunction -- for a disease that is often slow-moving and of no real consequence to survival if left untreated among older patients who are likely to die of other, unrelated causes.
However, the researchers pointed out that prostate cancer is not curable when it is caught late and has spread (or metastasized) to other parts of the body. They suggested that assessing to what degree a PSA diagnosis might reduce the risk of metastasis could be the best way to determine the value of the test.
To that end, Reddy and his team analyzed data on more than 1,700 prostate cancer patients who between 1986 and 1996 had been treated with either radiation therapy or surgery to take out their prostate gland and the surrounding tissue.
Noting that in the first half of the study period, PSA tests were not yet available, the authors compared the spread of the disease over the course of 10 years among those who had been diagnosed with a PSA test and those who had not.
Over the 10-year period, metastatic disease took hold among 13 percent of all the patients. However the researchers found that regardless of whether patients were categorized as having high-, medium-, or low-risk disease, those who had been diagnosed as a result of a PSA screening were significantly less likely than those who weren't to have seen their cancer spread during the decade following their original treatment.
Dr. Lionel L. Banez, an assistant professor of urologic surgery at Duke University Medical Center, said that the current study leans toward the relative benefits of prostate cancer screening.
"There is compelling evidence that PSA testing saves lives, especially when performed in an optimized strategy," he said. "For example, getting an initial PSA measurement at age 40 to properly assess baseline prostate cancer risk has been proven to be quite beneficial.
Nevertheless, Banez acknowledged that doctors need to interpret test results judiciously.
"The challenge," he stressed, "lies in ensuring that the risks for over-diagnosis and over-treatment, as well as potential decline in quality of life, are minimized or avoided."
More
Wednesday, October 20, 2010
United Health Care Program to Cut Individualized Treatmnts
UnitedHealthcare plans to announce on Wednesday a one-year project with five
oncology practices, offering doctors an additional fee. The new fee is meant
to encourage doctors to follow standard treatments rather than opting too
often for individualized and unproven courses of therapy, which can include
the most expensive drug combinations. By proposing a different type of
payment structure, companies hope to lower doctors' dependence on a system
that generates substantial sums for cancer specialists who routinely favor
top-of-the line treatments.
Regional insurers in some states, including California, Washington and
Pennsylvania, are negotiating similar limits with doctors and their clinics.
WellPoint, another large insurer, is developing a way of paying oncologists
to coordinate and manage patient care.
By almost any measure, cancer treatments can be exorbitantly expensive.
Cancer care in the United States costs almost $100 billion a year, and
medical bills for the average patient on chemotherapy can top $100,000 a
year.
http://www.nytimes.com/2010/10/20/health/policy/20cancer.html?_r=1&emc=eta1
What does this mean for forward movement with new treatments once they are
approved? Also are they considering anything other than cost? What about
QOL? Will this have an impact on the development of new treatments?
Kathy
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oncology practices, offering doctors an additional fee. The new fee is meant
to encourage doctors to follow standard treatments rather than opting too
often for individualized and unproven courses of therapy, which can include
the most expensive drug combinations. By proposing a different type of
payment structure, companies hope to lower doctors' dependence on a system
that generates substantial sums for cancer specialists who routinely favor
top-of-the line treatments.
Regional insurers in some states, including California, Washington and
Pennsylvania, are negotiating similar limits with doctors and their clinics.
WellPoint, another large insurer, is developing a way of paying oncologists
to coordinate and manage patient care.
By almost any measure, cancer treatments can be exorbitantly expensive.
Cancer care in the United States costs almost $100 billion a year, and
medical bills for the average patient on chemotherapy can top $100,000 a
year.
http://www.nytimes.com/2010/10/20/health/policy/20cancer.html?_r=1&emc=eta1
What does this mean for forward movement with new treatments once they are
approved? Also are they considering anything other than cost? What about
QOL? Will this have an impact on the development of new treatments?
Kathy
__._,_.___
Reply to sender | Reply to group | Reply via web post | Start a New Topic
Messages in this topic (1)
Recent Activity:
Visit Your Group
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Tuesday, October 12, 2010
Vitam Update
Knowing What’s Worth Paying For in Vitamins
CloseLinkedinDiggMixxMySpaceYahoo! BuzzPermalink By LESLEY ALDERMAN
Published: December 4, 2009
WHEN I stock up on ibuprofen (my painkiller of choice), I typically buy a 500-count bottle of a store brand like Kirkland or Rite Aid. After all, ibuprofen is ibuprofen. Each pill costs me about 3 cents — or only one-third the cost of 9-cent Advil.
Skip to next paragraph
Enlarge This Image
Chester Higgins Jr./The New York Times
A Vitamin Shoppe location in Manhattan. ConsumerLab.com found products sold by vitamin chains tended to be more reliable than drugstore brands.
Well
Share your thoughts on this column at the Well blog.
Sales over the last decade had been growing by about 4 percent annually. But this year, as more people are taking their health into their own hands, perhaps hoping to stave off doctor bills, vitamin sales are expected to grow by 8 percent to a total of $9.2 billion, according to Nutrition Business Journal, a market researcher and publisher.
About 42 percent of shoppers purchase their vitamins at natural and specialty retail outlets, like GNC and Whole Foods, according to the journal, while only 23 percent take the discount approach and buy their bottles at supermarkets and club stores. The other 35 percent buy through mail order or from a health care provider.
Of course, it’s controversial whether we should be taking vitamins at all. Recent studies have indicated that taking a multivitamin won’t protect you from heart disease or cancer. And experts maintain that if you eat well, you don’t need vitamin supplements.
“The evidence shows that a healthy diet and exercise are the best way to ward off disease; a vitamin cannot replace those benefits,” says Eric Rimm, associate professor of epidemiology and nutrition at the Harvard School of Public Health.
But what if you don’t eat well or are chronically stressed out? Then, Professor Rimm says, there may be some benefit from taking a multivitamin. “Certain subgroups, including women of child-bearing age attempting to get pregnant, may need specific supplements, like folic acid and omega-3,” he added.
As for the matter of cost: If you take only a daily multivitamin mainly as a medical insurance policy, it certainly won’t hurt your health — as long as you do not already eat a lot of fortified food. And it could help. But it will require spending some money. And if you take a multivitamin and a few individual vitamins and minerals, it’s even more worth your while to make sure you’re not paying more than you need to.
USE ONLY WHAT YOU NEED Popping too many vitamin pills is not only a waste of money but can be bad for your health. Talk to your doctor about what added vitamins or minerals you might require; you can ask for a blood test to learn what you might be lacking.
For example, if you don’t get enough vitamin D — many people who live in the northern states or who wear sunscreen everyday are low on this crucial vitamin — then buy just a D supplement. Standard multivitamins will probably not have the levels of D you require (many doctors suggest taking 1,000 to 2,000 international units a day).
If your doctor recommends a specific supplement, like omega-3, ask in what form you should be taking it.
FIND A REPUTABLE SOURCE Vitamins and minerals are commodity items, and every manufacturer has access to the same ingredients. For that reason, researchers and scientists say paying more for a name brand won’t necessarily buy you better vitamins.
“When we measure levels of vitamins in the blood, we find the levels are the same whether the person was taking a generic brand or a name brand,” says Dr. Rimm, who has been studying the effects of vitamins for 20 years.
That said, don’t be too cheap. Purchase your vitamins from well-known retailers that do a brisk business and restock frequently, whether that’s Costco or Drugstore.com. Vitamins lose their potency over time and must be stored at, or below, room temperature. If bottles are sitting on a shelf in warm room or in direct sunlight, they may degrade even before their expiration date.
PRICE MAY NOT MEAN QUALITY While the Food and Drug Administration regulates vitamins as part of the nutritional supplement industry, it does not test them before they are put on the shelves. The F.D.A. places the responsibility on the manufacturer to ensure that its dietary supplement products are safe before they are marketed. All of which means that no matter what the price, quality is not assured.
ConsumerLab.com, a company based in White Plains that tests hundreds of vitamins each year, finds that 30 percent of multivitamins have a quality problem: the pills might have more or less of a stated ingredient, or they might not dissolve properly.
Taking exception to such assertions is the vitamin industry’s trade group, the Council for Responsible Nutrition. In response to questions, the council released a statement from Andrew Shao, a vice president for scientific and regulatory affairs.
Mr. Shao said that the F.D.A. allowed for “a reasonable amount of variation” — which he characterized as up to 15 percent more of an ingredient than the label might indicate. Mr. Shao said that manufacturers frequently add slightly more of an ingredient to ensure that the amount is at least at the level claimed on the label as the product nears the end of its shelf life.
In any case, ConsumerLab.com says it has found a few patterns that consumers may find helpful. Products sold by vitamin chains tend to be more reliable than drugstore brands, and Wal-Mart and Costco’s vitamin lines are usually worth considering. In a recent test of multivitamins, ConsumerLab.com found that Equate-Mature Multivitamin 50+ sold by Wal-Mart was just as good as the name brand Centrum Silver, but at less than a nickel a day is half the price.
Puritan’s Pride, a catalog and online retailer, also has very good prices, and Dr. Cooperman says that its products are generally good.
Curious consumers can subscribe to ConsumerLab.com for $30 a year and learn how other supplement brands fare in the lab’s tests.
CERTIFICATION SYMBOLS One quality check you can make, although it is not a perfect screening, is to see whether a product is certified by one of several nonprofit organizations that check supplements for purity and quality.
The two most commonly used groups are the United States Pharmacopeia (www.usp.org) and NSF International (www.nsf.org), according to Mr. Shao. Manufacturers voluntarily submit a product for review and, if it passes, the product can bear an approval seal, such as USP or NSF. Because the process is voluntary, Mr. Shao points out, the absence of the seal does not necessarily mean the product is of poor quality.
But at least the seal should mean you know what you’re getting. And with vitamins, anything beyond that simple assurance may not be worth paying for.
CloseLinkedinDiggMixxMySpaceYahoo! BuzzPermalink By LESLEY ALDERMAN
Published: December 4, 2009
WHEN I stock up on ibuprofen (my painkiller of choice), I typically buy a 500-count bottle of a store brand like Kirkland or Rite Aid. After all, ibuprofen is ibuprofen. Each pill costs me about 3 cents — or only one-third the cost of 9-cent Advil.
Skip to next paragraph
Enlarge This Image
Chester Higgins Jr./The New York Times
A Vitamin Shoppe location in Manhattan. ConsumerLab.com found products sold by vitamin chains tended to be more reliable than drugstore brands.
Well
Share your thoughts on this column at the Well blog.
Sales over the last decade had been growing by about 4 percent annually. But this year, as more people are taking their health into their own hands, perhaps hoping to stave off doctor bills, vitamin sales are expected to grow by 8 percent to a total of $9.2 billion, according to Nutrition Business Journal, a market researcher and publisher.
About 42 percent of shoppers purchase their vitamins at natural and specialty retail outlets, like GNC and Whole Foods, according to the journal, while only 23 percent take the discount approach and buy their bottles at supermarkets and club stores. The other 35 percent buy through mail order or from a health care provider.
Of course, it’s controversial whether we should be taking vitamins at all. Recent studies have indicated that taking a multivitamin won’t protect you from heart disease or cancer. And experts maintain that if you eat well, you don’t need vitamin supplements.
“The evidence shows that a healthy diet and exercise are the best way to ward off disease; a vitamin cannot replace those benefits,” says Eric Rimm, associate professor of epidemiology and nutrition at the Harvard School of Public Health.
But what if you don’t eat well or are chronically stressed out? Then, Professor Rimm says, there may be some benefit from taking a multivitamin. “Certain subgroups, including women of child-bearing age attempting to get pregnant, may need specific supplements, like folic acid and omega-3,” he added.
As for the matter of cost: If you take only a daily multivitamin mainly as a medical insurance policy, it certainly won’t hurt your health — as long as you do not already eat a lot of fortified food. And it could help. But it will require spending some money. And if you take a multivitamin and a few individual vitamins and minerals, it’s even more worth your while to make sure you’re not paying more than you need to.
USE ONLY WHAT YOU NEED Popping too many vitamin pills is not only a waste of money but can be bad for your health. Talk to your doctor about what added vitamins or minerals you might require; you can ask for a blood test to learn what you might be lacking.
For example, if you don’t get enough vitamin D — many people who live in the northern states or who wear sunscreen everyday are low on this crucial vitamin — then buy just a D supplement. Standard multivitamins will probably not have the levels of D you require (many doctors suggest taking 1,000 to 2,000 international units a day).
If your doctor recommends a specific supplement, like omega-3, ask in what form you should be taking it.
FIND A REPUTABLE SOURCE Vitamins and minerals are commodity items, and every manufacturer has access to the same ingredients. For that reason, researchers and scientists say paying more for a name brand won’t necessarily buy you better vitamins.
“When we measure levels of vitamins in the blood, we find the levels are the same whether the person was taking a generic brand or a name brand,” says Dr. Rimm, who has been studying the effects of vitamins for 20 years.
That said, don’t be too cheap. Purchase your vitamins from well-known retailers that do a brisk business and restock frequently, whether that’s Costco or Drugstore.com. Vitamins lose their potency over time and must be stored at, or below, room temperature. If bottles are sitting on a shelf in warm room or in direct sunlight, they may degrade even before their expiration date.
PRICE MAY NOT MEAN QUALITY While the Food and Drug Administration regulates vitamins as part of the nutritional supplement industry, it does not test them before they are put on the shelves. The F.D.A. places the responsibility on the manufacturer to ensure that its dietary supplement products are safe before they are marketed. All of which means that no matter what the price, quality is not assured.
ConsumerLab.com, a company based in White Plains that tests hundreds of vitamins each year, finds that 30 percent of multivitamins have a quality problem: the pills might have more or less of a stated ingredient, or they might not dissolve properly.
Taking exception to such assertions is the vitamin industry’s trade group, the Council for Responsible Nutrition. In response to questions, the council released a statement from Andrew Shao, a vice president for scientific and regulatory affairs.
Mr. Shao said that the F.D.A. allowed for “a reasonable amount of variation” — which he characterized as up to 15 percent more of an ingredient than the label might indicate. Mr. Shao said that manufacturers frequently add slightly more of an ingredient to ensure that the amount is at least at the level claimed on the label as the product nears the end of its shelf life.
In any case, ConsumerLab.com says it has found a few patterns that consumers may find helpful. Products sold by vitamin chains tend to be more reliable than drugstore brands, and Wal-Mart and Costco’s vitamin lines are usually worth considering. In a recent test of multivitamins, ConsumerLab.com found that Equate-Mature Multivitamin 50+ sold by Wal-Mart was just as good as the name brand Centrum Silver, but at less than a nickel a day is half the price.
Puritan’s Pride, a catalog and online retailer, also has very good prices, and Dr. Cooperman says that its products are generally good.
Curious consumers can subscribe to ConsumerLab.com for $30 a year and learn how other supplement brands fare in the lab’s tests.
CERTIFICATION SYMBOLS One quality check you can make, although it is not a perfect screening, is to see whether a product is certified by one of several nonprofit organizations that check supplements for purity and quality.
The two most commonly used groups are the United States Pharmacopeia (www.usp.org) and NSF International (www.nsf.org), according to Mr. Shao. Manufacturers voluntarily submit a product for review and, if it passes, the product can bear an approval seal, such as USP or NSF. Because the process is voluntary, Mr. Shao points out, the absence of the seal does not necessarily mean the product is of poor quality.
But at least the seal should mean you know what you’re getting. And with vitamins, anything beyond that simple assurance may not be worth paying for.
Thursday, October 7, 2010
Nanoparticle PSA Test Improves Detection
Prostate Cancer Resources
Managing Bone Metastases and Pain
Side Effects of Prostate Cancer Treatment
Nanoparticle PSA Test Predicts If Prostate Cancer Will Return; Ultrasensitive Test Gives First Accurate Answer After Surgery
by Alton Parrish | BeforeItsNews.com | 06.02.2010
Men who have just had their cancerous prostate gland removed have one pressing question for their doctors: Am I cured? But conventional tests haven't been sensitive enough to provide a concrete answer.
Current tests that measure the level of protein called PSA (prostate-specific antigen), which signals the presence of cancer, often detect no PSA, only to have cancer return in up to 40 percent of the cases.
New research from Northwestern University Feinberg School of Medicine and the University International Institute for Nanotechnology shows that an ultrasensitive PSA test using nanoparticle-based technology (VeriSens™ PSA, Nanosphere, Inc., research-use-only) may be able to definitively predict after surgery if the cancer is cured long-term or if it will recur.
The new test, which is based upon assays invented at Northwestern in the laboratories of co-principal investigator Chad A. Mirkin, is 300 times more sensitive than currently available commercial tests and can detect a very low level of PSA that indicates the cancer has spread beyond the prostate. The test also may pick up cancer recurrence at a much earlier stage, when secondary treatment is most effective for a patient's survival.
"This test may provide early and more accurate answers," said co-principal investigator C. Shad Thaxton, M.D., an assistant professor of urology at Feinberg and a member of the Robert H. Lurie Comprehensive Cancer Center of Northwestern University.
"It detects PSA at levels in the blood that cannot be detected by conventional tests. It may allow physicians to act at the earliest and most sensitive time, which we know will provide the patient with the best chance of long-term survival."
This ability to quickly detect very low levels of PSA may enable doctors to diagnose men with prostate cancer recurrence years earlier than is currently possible. Prostate cancer is the second leading cause of cancer death for men in the United States.
Not only may the new test more accurately predict the course of the disease; it also gives an early indication of whether secondary treatments, such as radiation and hormone therapy, are working. If not, then doctors can quickly begin alternative treatment and refer patients to clinical trials.
The study results will be presented at the American Urological Association 2010 Annual Meeting. These and the results of other Northwestern PSA studies will be presented at the meeting by Lee Zhao, Dae Kim and Hannah Alphs, urology residents at Feinberg.
"These studies suggest that the nanotechnology PSA test might become the preferred postoperative PSA test for men who have been treated with radical prostatectomy," said William Catalona, M.D., professor of urology at Feinberg, a physician at Northwestern Memorial Hospital and director of the clinical prostate cancer program at the Lurie Cancer Center.
"It should be especially useful in the early identification of men who would benefit from adjuvant postoperative radiation therapy and those who need postoperative salvage radiation therapy for recurrence."
Catalona, a senior investigator on the study, was the first to demonstrate that the PSA test could be used as a screening test for prostate cancer.
The study confirms and builds on the previous findings of a 2009 pilot study Thaxton conducted with Mirkin, the George B. Rathmann Professor of Chemistry in the Weinberg College of Arts and Sciences, and other colleagues.
PSA is a protein normally secreted out of the prostate cells into the semen in high concentrations. Usually, very little diffuses into the blood stream, and the normal PSA value for men without prostate disease is less than 2 nanograms per milliliter.
When the prostate gland has a disease process, such as inflammation, benign enlargement or cancer, the barriers to PSA diffusion into the blood stream are breached, and PSA levels rise.
In a man who has his cancerous prostate removed, there should be no PSA in the blood except for a minute amount produced by the periurethral glands. However, any PSA produced by cancer recurrence ends up in the blood stream and can be detected earlier with the more sensitive nanotechnology PSA assay.
For the new study, researchers obtained blood serum retrospectively from men whose PSA serum samples had been frozen after surgery and whose assays (blood analysis) showed an undetectable PSA level based on the conventional test.
Northwestern researchers then tested those serum samples using the more sensitive nanotechnology-based test. They wanted to see if they could detect PSA at levels below the limit of the conventional test, and if those results could predict the cancer outcome for those patients, who were followed for up to 10 years.
Using the new test, Thaxton and colleagues found that the low and non-rising PSA levels (presumably produced by the normal periurethral glands) of patients meant that the prostate cancer was effectively cured and did not return over a period of at least 10 years. Scientists also found a PSA level higher than that expected from the periurethral glands based on the new test meant the patients would have their disease recur.
As result of the study, researchers were able to assign a PSA level number to a cure for the first time as well as a number that indicated the disease would recur and if it would recur aggressively.
These newly identified levels were below what could have been detected with the conventional PSA test. The researchers were able to quantify PSA values at less than 0.1 nanograms per milliliter, the clinical limit of detection for commercial assays.
Thaxton said the next step for scientists is a prospective clinical trial to compare the nanoparticle-enhanced PSA assay to traditional PSA assays and determine if earlier detection and treatment can save lives.
Managing Bone Metastases and Pain
Side Effects of Prostate Cancer Treatment
Nanoparticle PSA Test Predicts If Prostate Cancer Will Return; Ultrasensitive Test Gives First Accurate Answer After Surgery
by Alton Parrish | BeforeItsNews.com | 06.02.2010
Men who have just had their cancerous prostate gland removed have one pressing question for their doctors: Am I cured? But conventional tests haven't been sensitive enough to provide a concrete answer.
Current tests that measure the level of protein called PSA (prostate-specific antigen), which signals the presence of cancer, often detect no PSA, only to have cancer return in up to 40 percent of the cases.
New research from Northwestern University Feinberg School of Medicine and the University International Institute for Nanotechnology shows that an ultrasensitive PSA test using nanoparticle-based technology (VeriSens™ PSA, Nanosphere, Inc., research-use-only) may be able to definitively predict after surgery if the cancer is cured long-term or if it will recur.
The new test, which is based upon assays invented at Northwestern in the laboratories of co-principal investigator Chad A. Mirkin, is 300 times more sensitive than currently available commercial tests and can detect a very low level of PSA that indicates the cancer has spread beyond the prostate. The test also may pick up cancer recurrence at a much earlier stage, when secondary treatment is most effective for a patient's survival.
"This test may provide early and more accurate answers," said co-principal investigator C. Shad Thaxton, M.D., an assistant professor of urology at Feinberg and a member of the Robert H. Lurie Comprehensive Cancer Center of Northwestern University.
"It detects PSA at levels in the blood that cannot be detected by conventional tests. It may allow physicians to act at the earliest and most sensitive time, which we know will provide the patient with the best chance of long-term survival."
This ability to quickly detect very low levels of PSA may enable doctors to diagnose men with prostate cancer recurrence years earlier than is currently possible. Prostate cancer is the second leading cause of cancer death for men in the United States.
Not only may the new test more accurately predict the course of the disease; it also gives an early indication of whether secondary treatments, such as radiation and hormone therapy, are working. If not, then doctors can quickly begin alternative treatment and refer patients to clinical trials.
The study results will be presented at the American Urological Association 2010 Annual Meeting. These and the results of other Northwestern PSA studies will be presented at the meeting by Lee Zhao, Dae Kim and Hannah Alphs, urology residents at Feinberg.
"These studies suggest that the nanotechnology PSA test might become the preferred postoperative PSA test for men who have been treated with radical prostatectomy," said William Catalona, M.D., professor of urology at Feinberg, a physician at Northwestern Memorial Hospital and director of the clinical prostate cancer program at the Lurie Cancer Center.
"It should be especially useful in the early identification of men who would benefit from adjuvant postoperative radiation therapy and those who need postoperative salvage radiation therapy for recurrence."
Catalona, a senior investigator on the study, was the first to demonstrate that the PSA test could be used as a screening test for prostate cancer.
The study confirms and builds on the previous findings of a 2009 pilot study Thaxton conducted with Mirkin, the George B. Rathmann Professor of Chemistry in the Weinberg College of Arts and Sciences, and other colleagues.
PSA is a protein normally secreted out of the prostate cells into the semen in high concentrations. Usually, very little diffuses into the blood stream, and the normal PSA value for men without prostate disease is less than 2 nanograms per milliliter.
When the prostate gland has a disease process, such as inflammation, benign enlargement or cancer, the barriers to PSA diffusion into the blood stream are breached, and PSA levels rise.
In a man who has his cancerous prostate removed, there should be no PSA in the blood except for a minute amount produced by the periurethral glands. However, any PSA produced by cancer recurrence ends up in the blood stream and can be detected earlier with the more sensitive nanotechnology PSA assay.
For the new study, researchers obtained blood serum retrospectively from men whose PSA serum samples had been frozen after surgery and whose assays (blood analysis) showed an undetectable PSA level based on the conventional test.
Northwestern researchers then tested those serum samples using the more sensitive nanotechnology-based test. They wanted to see if they could detect PSA at levels below the limit of the conventional test, and if those results could predict the cancer outcome for those patients, who were followed for up to 10 years.
Using the new test, Thaxton and colleagues found that the low and non-rising PSA levels (presumably produced by the normal periurethral glands) of patients meant that the prostate cancer was effectively cured and did not return over a period of at least 10 years. Scientists also found a PSA level higher than that expected from the periurethral glands based on the new test meant the patients would have their disease recur.
As result of the study, researchers were able to assign a PSA level number to a cure for the first time as well as a number that indicated the disease would recur and if it would recur aggressively.
These newly identified levels were below what could have been detected with the conventional PSA test. The researchers were able to quantify PSA values at less than 0.1 nanograms per milliliter, the clinical limit of detection for commercial assays.
Thaxton said the next step for scientists is a prospective clinical trial to compare the nanoparticle-enhanced PSA assay to traditional PSA assays and determine if earlier detection and treatment can save lives.
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