PSA Test
PSA Test a Thing of the Past? MONDAY, May 10 (HealthDayNews) — The PSA test, long the gold standard for deciding who should have a biopsy for prostate cancer, may have outlived its usefulness for the most part.
Stanford University researchers say PSA (prostate specific antigen) levels bear little relationship to the severity of a cancer these days. They presented their finding May 9 at the American Urology Association’s annual meeting in San Francisco.
“”We need to recognize that PSA is no longer a marker for prostate cancer,”" said study author Dr. Thomas A. Stamey, a professor of urology at Stanford University School of Medicine. “”We urgently need to find a new marker for prostate cancer, and that marker must be proportional to how much cancer you have.”"
“”We have been so thorough and effective in screening for prostate cancer over this 20-year period that PSA no longer has a relationship to prostate cancer,”" Stamey said. “”Because we all develop the cancer, we’re now removing prostates from men whose cancer is so small that they do not need the procedure. We’re finding all these little cancers that are never going to be a danger to the patient.”"
“”In smaller cancers, the PSA test is not relevant anymore,”" Stamey explained. “”You might as well biopsy a man because he has blue eyes.”"
PSA is a protein produced by the cells of the prostate gland. Because blood levels of the antigen tend to rise as the gland enlarges, it has been used for years as a test of whether a person needs a biopsy for cancer. The test, however, is not foolproof.
“”People’s perceptions [are] that if your PSA is a certain level, you’re very likely or you do have prostate cancer, and that is incorrect,”" said Dr. Mark Soloway, chairman of the department of urology at the University of Miami School of Medicine.
“”The PSA test is a very good test. It’s not a perfect test, especially in younger men,”" added Dr. Jay Brooks, chief of hematology/oncology at the Ochsner Clinic Foundation in New Orleans.
To see how the efficacy of the PSA test might have waned, researchers in Stamey’s lab reexamined every prostate that had been removed since 1983 (1,317 of them) and compared the size of the cancer with blood PSA levels. None of the cancers had been treated with chemotherapy, radiation, or hormones before surgery.
Each cancer was rated on eight or 10 different parameters thought to indicate how aggressive the cancer was, including the size of the tumor and its grade.
Stamey then divided the samples into four five-year periods to see what had happened to the qualities of the cancers over time.
“”What we showed was that in the first five years, the cancers were related to the level of serum PSA,”" Stamey said. “”Then in the next five years, they were still bad but not as bad as the first five years. Then in the third five-year period, they were better and better. And in the last five years ending Jan. 1 of this year, the cancers were so small they had no relationship to serum PSA.”"
Twenty years ago, 80 percent of cancers were detected by digital rectal examination; only 20 percent of cancers are now detected that way, Stamey explained.
Instead, PSA levels today are driven by benign enlargement of the prostate, a condition that does not usually require surgery.
The concept that the PSA test is not foolproof is not an entirely new one. “”The point is well taken that in microscopic disease, the volume of cancer is clearly overshadowed by the volume of noncancer, so that the cancer cannot be the cause of the elevated PSA,”" said Dr. John Phillips, physician-in-charge of urologic oncology at Beth Israel Medical Center in New York City.
The question now is what can replace it. “”People are trying to find other ways of finding cancer,”" Phillips added.
As a matter of fact, University of Pittsburgh researchers who presented at the same conference reported that additional testing for a protein called early prostate cancer antigen (EPCA) might mean prostate cancer could be detected as many as five years earlier than with just the PSA test.
“”We would like a perfect test that would only find biologically significant cancers,”" Soloway said. “”Today we can’t distinguish between those with indolent cancer and those whose cancers threaten their life. We need another way. That’s going to be a difficult task.”"
In the meantime, the American Urological Association issued a statement that, for the time being, the PSA test in combination with a digital rectal exam and a full medical history is the best way to determine when a biopsy might be necessary
Pine Bark Extract Boosts Heart Health
Pine Bark Extract Boost Diabetics’ Heart Health May 13, 2008
Supplements of extracts from French maritime pine bark reduce blood pressure and the use of blood pressure medication among diabetics, concludes results from a new study.
Blood pressure control was achieved in 58 per cent of study participants, and a halving of the use of medication, among 48 participants randomly assigned to daily supplements of pine bark extract or placebo for 12 weeks. The results of the new study, published in the May issue of the journal Nutrition Research, is of particular importance for diabetics who are reportedly two to four times more likely to suffer from heart disease than non-diabetics “”These data confirm the hypothesis that pine bark extract improves diabetes control, reduces antihypertensive medicine use, and may favour a reduction in cardiovascular disease risk in individuals with type 2 diabetes,”" wrote lead author Sherma Zibadi from the University of Arizona. Indeed, previous studies have reported potential health benefits for the extract, including hypertension, asthma, chronic venous insufficiency, osteoarthritis, deep vein thrombosis, diabetes management, and diabetic leg ulcers. The new study recruited diabetic subjects with an average age of 60 and randomly assigned them to receive daily supplements of pine bark extract (125 mg) or placebo for 12 weeks in a randomized, double-blind, placebo-controlled trial with parallel-group design. All subjects were receiving pharmaceutical anti-hypertension treatment (angiotensin- converting enzyme [ACE] inhibitors). At the end of the study, Zibadi and co-workers report that 58.3 per cent of subjects in the pine bark extract group experienced blood pressure control, defined as attaining a stable systolic blood pressure, compared to 20.8 per cent in the placebo group. Moreover, use of ACE inhibitors was reduced by 50 per cent in the group receiving the pine bark extract Improvements in measures of diabetes control were also recorded, with a 23.7 mg/dL reduction in fasting blood glucose levels in the pine bark extract group, compared to only 5.7 mg/dL in the placebo group. Improvements in LDL-cholesterol, a marker of cardiovascular health, were recorded in the pine bark extract-supplemented group. After eight and 12 weeks of supplementation, decreases of 11.6 and 12.7 mg/dL were observed, respectively, compared with placebo. Mechanism of Action In attempting to understand the benefits of the pine bark extract on cardiovascular health of the diabetics, the researchers noted that the blood pressure lowering effects may be due to a suppression of serum endothelin-1, a protein that restricts blood vessels and reported to be found in higher levels than normal in type 2 diabetics and hypertensives. On the other hand, the authors could not rule out the potential of an inhibitory effect on ACE, which could improve blood flow and subsequently blood pressure. Finally, other studies have reported a potential benefit from pine bark extract on the production of the potent vasodilator, nitric oxide (NO). Limitations About 26.5 million people are affected by diabetes in the European Union, United States, and Canada equal to four per cent of the total population. This figure is projected to increase to 40 million by 2030. In the US, there are over 20 million people with diabetes, equal to seven per cent of the population. The total costs are thought to be as much as $132 billion, with $92 billion being direct costs from medication, according to 2002 American Diabetes Association figures.
Source: Nutrition Research (Elsevier) May 2008, Volume 28, Issue 5, Pages 315-320 “”Reduction of cardiovascular risk factors in subjects with type 2 diabetes by Pycnogenol supplementation”" Authors: S. Zibadi, P.J. Rohdewald, D. Park, R.R. Watson