Green tea and prostate cancer

Another reason to drink green tea - at least for men. A recent study reports that consumption of green tea may slow down the progression of prostate cancer. The study looked at 26 men, aged 41 to 72 years old who were diagnosed with prostate cancer and due to undergo radical prostatectomy.

The study patients were given a daily dose of four capsules of Polyphenon E, which is equivalent to about 12 cups of concentrated normally brewed green tea, for 12 to 73 days until the day before surgery. They were monitored for serum concentrations of the following biomarkers: hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF) and prostate specific antigen (PSA). HGF and VEGF levels are especially relevant because they are good prognostic indicators of metastasis.

The results showed that consumption of Polyphenon E led to a significant reduction in levels of HGF, VEGF and PSA markers, even up to 30% in some cases.

According to researcher Dr. James A. Cardelli, professor and director of basic and translational research in the Feist-Weiller Cancer Center, LSU Health Sciences Center-Shreveport

“The investigational agent used in the trial, Polyphenon E (provided by Polyphenon Pharma) may have the potential to lower the incidence and slow the progression of prostate cancer”.

Green tea is rich in antioxidant phytochemicals such as polyphenols, catechins and flavanols. It is said that green tea contains more antioxidant compared to other drinks such as black tea, wine or hot chocolate because of the minimal oxidation it undergoes during its production. This is not the first study to demonstrate the health benefits of green tea. Several studies have demonstrated the cardiovascular benefits of green tea.

Another study by Italian researchers “demonstrated that consumption of green tea polyphenols reduced the risk of developing prostate cancer in men with high-grade prostate intraepithelial neoplasia (HGPIN).”

Japanese researchers reported that green can prevent lifestyle-related chronic diseases such as cardiovascular disease and cancer.

In 2003, Dutch researchers reported that tea is “the most consumed drink in the world after water, well ahead of coffee, beer, wine and carbonated soft drinks.” Unfortunately, this trend has changed since then as carbonated drinks became more and more popular.

Currently, further studies are being conducted using Polyphenon E, including one in breast cancer patients.

Dr. Cardelli continues to say:

“There is reasonably good evidence that many cancers are preventable, and our studies using plant-derived substances support the idea that plant compounds found in a healthy diet can play a role in preventing cancer development and progression.”

               

Is this new test a better alternative to PSA?

With the current controversy related to the unreliability of the PSA test, the news of a new promising blood test to detect prostate cancer is very welcome.

PSA stands for prostate-specific antigens and levels of PSA in the blood are used as biomarkers for prostate cancer. Unfortunately, the method gives such a high rate of false positives that its usefulness has been questioned lately.

Researchers at the Dana Farber Institute tested the six-gene whole blood RNA transcript-based diagnostic test developed by Source MDx in Boulder, Colo in terms of accuracy, sensitivity, and specificity. Sensitivity is the ability of a test to detect the disease. Specificity is the ability of a test to rule out the presence of the disease.

The study revealed that the six-gene model [test] was more accurate than PSA alone at predicting cancer if you had it and no cancer if you didn’t. In addition, the test’s accuracy increased even more when sued in combination with the PSA test. Combined, the two tests exhibited a diagnostic accuracy of more than 90% in terms of sensitivity and specificity. In addition, the new test eliminated the majority of false positive results produced by the PSA test.

According to Dr. William K. Oh, clinical director of the Lank Center for Genitourinary Oncology at Dana-Farber

These findings are very encouraging and suggest that this new test could spare tens of thousands of men from undergoing an unnecessary biopsy. However, until we can verify our findings, it is important to recognize that the PSA test, despite its limitations, is still the best test available for diagnosing prostate cancer at this time.”

Currently, cancer experts are divided as to the benefits of prostate cancer screening using PSA. Men who tested positive for elevated levels of PSA are usually referred to have a prostate biopsy. Almost two thirds of men who tested positive in the PSA test would test negative for the biopsy. The prostate biopsy as such is painful, invasive, and can lead to complication. This high rate of “false positive” PSA test results underscores the need for a more accurate method for detecting prostate cancer, according to Dr. Oh.

The blood RNA transcript-based test presents a hope that someday prostate cancer screening would become a routine procedure using a highly reliable method similar to the Pap smear for cervical cancer and mammography for breast cancer.

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Can a healthy lifestyle alter your genes and treat your cancer?

 We’ve heard this statement of resignation before: “I can’t do anything about it. It’s in my genes.” Indeed, many diseases have been linked to genetics, including heart disease, mental illness, and cancer. However, this study by researchers at the Preventive Medicine Research Institute in Sausalito, California suggests that there might be something we can do after all, and that changing our lifestyle for the better can trigger changes in certain genes that otherwise make us predisposed to disease.

The researchers followed up 30 men diagnosed with low-risk prostate cancer and who decided not to undergo currently available treatments such as removal of the prostate gland, radiation therapy or hormone therapy. However, they opted for a major lifestyle change program which consisted of

eating a diet rich in fruits, vegetables, whole grains, legumes and soy products, moderate exercise such as walking for half an hour a day, and an hour of daily stress management methods such as meditation.

Indeed there were some expected health benefits observed after 3 months of lifestyle change therapy, namely:

• Weight loss
• Improved cardiovascular health

However, the researchers found some unexpected but nevertheless beneficial effects in the form of “changes in activity in about 500 genes — including 48 that were turned on and 453 genes that were turned off…The activity of disease-preventing genes increased while a number of disease-promoting genes, including those involved in prostate cancer and breast cancer, shut down.”

The researchers also performed prostate biopsies before and after the 3-month therapy and found observable clinical improvement.

It is incredible to see these changes in such as short period of time but of course the study only looked at patients with a type of prostate cancer that is less likely to be aggressive or malignant. However, the study demonstrates the undeniable health benefits that a healthy lifestyle can bring. The lifestyle change therapy is especially relevant to prostate cancer patients who are faced with a lot of uncertainties concerning the early screening tests (e.g. PSA) and treatments available. Many patients tend to opt of the so-called “watchful waiting” management. If this management approach is coupled with a lifestyle change therapy, the chances of beating prostate cancer will considerably increase.

According to lead researcher Dr. Dean Ornish

“‘In just three months, I can change hundreds of my genes simply by changing what I eat and how I live?’ That’s pretty exciting. The implications of our study are not limited to men with prostate cancer.”

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Know your interventions: focal cryoablation for prostate cancer

The recent contradictory results of two large scale studies that investigated the risks and benefits of prostate cancer screening brought about the question of overdiagnosis and overtreatment. It also highlighted the need for less radical and minimally invasive treatment.

Men diagnosed with prostate cancer are usually recommended to undergo prostatectomy, which is the surgical removal of the prostate gland. No one can deny that this treatment is radical and highly invasive, and sadly, sometimes unnecessary. This is because it is extremely difficult to determine whether a prostate tumor is malignant or benign, slow-growing or aggressive and the only way to be sure is looking at the tumor in the lab, long after the organ ahs been removed.

Researchers presented a study at the Society of Interventional Radiology’s 34th Annual Scientific Meeting that may just have the answer. Instead of bombarding tumors with radiation or chemotherapeutic agents, this new technique uses freezing technology. In the treatment of prostate cancer, this method is called “male lumpectomy” or “focal cryoablation.” Instead of surgically removing the entire prostate gland or subject the whole gland to radiation, interventional radiologists can localize the tumor and destroy it by freezing.

With cryoablation, interventional radiologists insert a probe through the skin, using imaging to guide the needle to the tumor; the probe then circulates extremely cold gas to freeze and destroy the cancerous tissue. This minimally invasive treatment targets only the cancer itself, sparing healthy tissue in and around the prostate gland rather than destroying it, as traditional approaches do.

This treatment method has the following advantages over traditional treatments:

• Minimally invasive
• Less traumatic
• More likely to preserve sexual function
• Less likely to interfere with urinary function
• No major complications
• Fewer side effects

The technique has long been used in breast cancer treatment where instead of radical mastectomy, surgical breast lumpectomy is now the preferred method. Unlike breast tumors, however, surgical lumpectomy of prostate tumors is technically not feasible. But the use of cryoablation technique seems to solve this problem. “Cryoablation spares as much as possible of the prostate gland and its neurovascular bundles, limiting the side effects of bladder control problems (incontinence) and erectile dysfunction (impotence) that result from more radical prostate cancer treatments.”

Many health experts advocate the “watchful waiting” strategy over traditional but radical prostatectomy. Advocates of focal cryoablation claim it, too, presents an advantage over the “watchful waiting” approach because all other treatment options are preserved.

The researchers further recommend that focal ablation should be complemented by the 3-D transperineal biopsy. Using 3-D mapping technique, this biopsy can detect very small tumors that can then easily be destroyed by cryoablation.

Indeed, this new development gives hope to men. Current guidelines recommend that men should get screened for prostate cancer at age 50 and above.

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Screening for prostate cancer: the pros and the cons

Resource post for March

In almost all diseases, screening and early detection is the key to management and cure. What used to be fatal diagnoses of late stage breast and cervical cancer have now become uncommon as more and more cases are detected early by regular screening.

In men, prostate cancer is the third leading cause of cancer mortality. The Institute for Cancer Research (ICR) in the UK gives us the following statistics:

As many as 80% of men develop prostate cancer during their lifetime, but in most cases it does not cause any ill health. Around 6% of men experience symptoms of the disease, while 3% of men die of prostate cancer.

Screening for prostate cancer is done in two ways, namely:

PSA test. Prostate-specific antigen (PSA) is protein biomarker produced by prostate cells. PSA is normally present in blood in low amounts. Cancerous (malignant) prostate cells are expected to produce more PSA than noncancerous cells, leading to elevated PSA levels in the blood. PSA testing consists mainly of testing for levels of the antigen in a blood sample. If PSA levels are found to be high, other tests, including a prostate biopsy may be deemed necessary. Currently, the American Urologic Association, the American Cancer Society, and the National Comprehensive Cancer Network recommend that all men 50 years and older should have annual PSA tests. Men with high risk profiles (e.g. of African American heritage, family history of prostate cancer) are advised to get tested starting at the age of 40.

Digital rectal examination. This examination is performed by a doctor by inserting a lubricated finger through the rectum. Through the walls of the rectum, the doctor can feel for structural abnormalities (bumps, growths, enlargement) in the prostate.

The usefulness of the PSA test in screening for prostate cancer has always been a subject of controversy. Some studies have produced inconclusive results regarding its benefits as well as its side effects. Potential risks include, unnecessary invasive testing (biopsy), and unnecessary treatment with serious side effects, and unnecessary expense. However, 95% of male urologists and 78% of male primary care clinicians admit to having had a PSA test themselves. PSA gives the potential benefits of catching cancer at its early stages, with better prognosis.

In the March issue of the New England Journal of Medicine, results of two studies on PSA screening were presented: one study conducted in the US, and one study conducted in Europe. Unfortunately, instead of resolving the controversy once and for all, the two studies actually produced contradicting results.

The American study:

Mortality Results from a Randomized Prostate-Cancer Screening Trial
This study is part of the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. The study looked at 76,693 men from 1993 to 2001. About 50% of the participants had PSA screening every year for 6 years and digital rectal examination for 4 years. The other half did not undergo screening for prostate cancer. The PLCO results showed that after 7 to 10 years the incidence of prostate cancer was 116 per 10,000 person-years in the screening group and 95 in the control group. The incidence of death per 10,000 person-years was 2.0 (50 deaths) in the screening group and 1.7 (44 deaths) in the control group. Statistically speaking, there was no difference in cancer incidence and mortality between the screened group and the unscreened group.

The European study:

Screening and Prostate-Cancer Mortality in a Randomized European Study
The European Randomized Study of Screening for Prostate Cancer (ERSPC) started in the 1990s and followed up 182,000 men aged between 50 and 74 years old for about 12 years. The study had also two groups. In one group, PSA screening way conducted on average, once a year. The other group did not undergo PSA screening. The study was conducted in 8 European countries, namely Belgium, Finland, France, Italy, Netherlands, Spain, Sweden and Switzerland The results of the study showed that

PSA-based screening reduced the rate of death from prostate cancer by 20% but was associated with a high risk of overdiagnosis

Both studies will now look into the cost effectiveness and overall quality of life of the PSA testing. Although PSA testing itself is non-invasive, the subsequent confirmatory tests such as biopsy can be invasive and present with risks.

About PSA testing

Many experts observe that PSA testing is not specific enough and has a 30% rate of false positives - e.g. cancers are non-aggressive and are indolent or slow-growing. It is sometimes difficult to decide which really cancer needs treatment which one doesn’t. While many would opt to be on the safe side and go for early treatment, the treatment comes with side effects such as impotence and incontinence.

A more conservative form of prostate cancer monitoring is called “Active Surveillance which aims to individualise the management of early prostate cancer by selecting only those men with significant cancers for curative treatment… Patients on active surveillance are closely monitored using PSA blood tests and repeat prostate biopsies. The choice between continued observation and curative treatment is based on evidence of disease progression during this monitoring.”

It seems that prostate cancer screening by PSA testing have its pros and cons. In the end, it is always a question whether the benefits outweigh the costs.

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Killing two birds with one stone: lower your cholesterol, lower your prostate cancer risk

There are two big “C’s” - cardiovascular disease and cancer - that we are fighting today. A study published in the American Journal of Pathology reveals that high cholesterol levels not only cause atherosclerosis and heart disease but can also contribute to prostate cancer development and progression.

The link between cholesterol and cancer has been observed in laboratory mice fed with high fat, high cholesterol diet and treated with the cholesterol uptake-blocking drug ezetimibe. The researchers observed that the fatty cholesterol rich diets promoted tumor growth whereas the drug ezetimibe prevented the tumor growth while lowering cholesterol levels at the same time. Ezetimibe works by blocking the absorption of cholesterol by the intestine.

Thus, the study results suggest

“cholesterol reduction, which is routinely accomplished pharmacologically in humans, may reduce angiogenesis, ultimately leading to less aggressive tumors.”

Prostate cancer is a very common cancer, affecting approximately 1 in 6 American men. Previous research studies have linked prostate cancer with the so-called typical “Western diet” which is rich in fat and high cholesterol. Progression of prostate tumors have also been linked to serum cholesterol levels.

Last December, the International Agency for Research on Cancer (IARC) of the World Health Organization (WHO) predicted that cancer will overtake cardiovascular disease as the world’s top killer in 2010. When the projected cancer statistics were published last year, it was noted that there are similarities between the two big C’s. The American Heart Association (AHA) issued a statement saying that

“The risk and demographic factors they have identified as predictive of an increase in cancer deaths are the very same factors that are going to result in more cardiovascular deaths, too, so we are on the same track.”

Some of these factors, mainly lifestyle factors are:

• tobacco use
• high calorie, high-saturated and trans-fat diets

The fact that people in less developed countries are rapidly adopting the “Western lifestyle” listed above led to the prediction that cancer and cardiovascular disease will rapidly increase worldwide despite the fact that they are currently declining in the US and other developed countries

According to AHA President Tim Garner

The American Heart Association has been working for decades to move out of that ‘top spot’ of being the number one killer. It’s a distinction that none of us want to have. And unless we can do better in reducing these risk factors in the United States, it may be a long time before we can shed the title of number one.”

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Cancer breakthrough: urine test for prostate cancer

The current standard test for prostate cancer is testing for concentrations of the biomarker prostate-specific antigen (PSA), in the blood. . The blood test is then complemented by biopsy which could determine the stage of the disease and whether the disease is slow-going or aggressive. Although blood testing and biopsies are standard procedures in diagnostic medicine in general, the methods are still rather invasive and pose risks for both patient and health care professional. Thus, the news of a simple urine test for prostate cancer is certainly welcome in the health care industry.

Researchers University of Michigan in Ann Arbor have identified a molecule in the urine that could reveal the state of disease in prostate cancer patients. The molecule has been identified as sarcosine

“a derivative of the amino acid glycine called sarcosine, after close inspection of all the metabolites found in 262 samples from prostate cancer patients - all of whom had different stages of the disease - including benign cells to aggressive metastasized cancers able to spread to other organs. Metabolites are the substances involved in or produced by the chemical reactions that take place in the body, and the concentrations of these chemicals can change as cancer progresses.” (Source: Nature News).

When tested in the lab, sarcosine induced normal prostate cells to behave like cancerous cells, indicating that the molecule is not only a biomarker, but also plays an active role in cancer development, making it a potential target for prostate cancer treatment.

The search for biomarkers for diseases has become the Holy Grail for biomedical researchers. While the search has proven to be easy in some diseases, it has proven to be difficult and complicated for others. Urine biomarkers have proven to be useful in urological, gynecological infections but not in cancer (until now). Urine as source of biomarker has the advantages of non-invasive collection method, an almost unlimited supply, can remain stable for long periods without special treatment or storage. However, studies have shown that protein content in urine can be low and variable while the high salt content seems to interfere with analytical methods.

According to Cancer Research UK, prostate cancer is the most common form of cancer in British men with about 35,000 new cases diagnosed each year in the UK alone. “The lifetime risk for being diagnosed with prostate cancer is 1 in 14.” In the US, 186,320 new cases were diagnosed and 28,660 deaths were reported in 2008 alone, according to the US National Cancer Institute.

 The sarcosine test has the advantage of testing for prostate cancer as well as showing the stage of the disease and its aggressiveness without resorting to biopsy.  It is currently being tried out in clinical trials is Europe.

               

Prostate cancer screening and marital status

As in most diseases, early detection of prostate cancer can greatly improve the chances of treatment and survival. According to the Mayo Clinic, about 40% of prostate cancer cases are not detected until they have spread beyond the prostate gland. A lot of cases are asymptomatic in its early stages so that screening by a medical professional is sometimes the only way to diagnose the disease. However, some men are wont to avoid the issue. That is why it is important to understand psychosocial factors that influence men from having or not having prostate cancer screening.

Screening for prostate cancer can be done in many ways but the two most commonly recommended diagnostic tests are:

• The prostate-specific antigen (PSA) test, which looks at the levels of the biomarker PSA in the blood. High PSA levels can indicate inflammation or enlargement or cancer of the prostate
• The digital rectal examination (DRE) is done by a medical professional by manual examination of the rectum. About 70% of prostate tumors develop on the outer part of the gland, which can then be felt by a finger inserted in the rectum.

Dr. Lauren Wallner of University of Michigan, Ann Arbor and her colleagues investigated the factors that influenced men to get tested for this deadly disease. Medical data of 2447 men from the Olmsted County Study on Urinary Symptoms and Health Status were collected and used for this specific study. These men were randomly selected in 1990 and information on family history of prostate cancer, prostate cancer concerns, marital status and medical and laboratory records was analyzed.

The patients who were included in the study have an age median of 51.9 years, 85% of which were married or living with someone. Approximately 9% of them have history of prostate cancer in the family while about 10% have shown concern or worry about the disease.

Statistical analysis showed that men with prostate cancer history in the family do have prostate cancer screening more frequently that those without history. Men who also showed more concern or worry more about the disease are more likely to have frequent screening that those who don’t. Married men or those with live-in partners are also found to have frequent prostate cancer screening compared to their single, unattached counterparts.

“Among men with a family history of prostate cancer, those who were married or living with someone were more likely to get screened compared with men who were not, suggesting a role for marital status in influencing screening behaviour,” the researchers concludes.

Could it be that emotional attachments make men more conscious of their health?

               

Selenium and vitamin E supplements do not prevent prostate cancer

A disappointing end to an otherwise promising clinical trial. It was known as the SELECT (Selenium and Vitamin E Cancer Prevention Trial) and it evaluated whether supplementation with selenium and Vitamin E can prevent prostate cancer. The large-scale long-term study of the National Cancer Institute (NCI) included more than 35,000 male participants in the US, Puerto Rico and Canada. They were randomly assigned to one of 3 groups: group 1 took vitamin E only, group 2 took selenium only, group 3 took both, and group 4 took placebos only.

After, on the average, 5 years of follow up, the NCI decided to cut short the study because of “concerning” findings, namely:

• The analysis found no lower risk of prostate cancer in men taking the supplements, either alone or together.
• Men who were taking only vitamin E actually had a slightly higher risk of developing prostate cancer.
• Men taking only selenium seemed to have a slightly higher risk of developing diabetes.

The “slight increased risks” observed were not statistically significant, and could therefore be due to pure chance. However, with such major health risks, there are no taking chances. One thing remains clear: that supplementation with vitamin E and selenium do not prevent prostate cancer.

This is not the first indication that supplementation with vitamins and minerals may actually have adverse effects to our health. In 2007, Danish researchers conducted a meta-analysis of studies on the antioxidant supplementation with beta-carotene, selenium, vitamins A, C, and E. The results of the study suggest that antioxidant supplements do not prevent cancer or cardiovascular disease but may even increase the risk of overall mortality.

Several studies evaluated whether antioxidant supplements can prevent other types of cancer, with negative results. In one study, the authors concluded that “we could not find convincing evidence that antioxidant supplements prevent gastrointestinal cancers.”

Does this mean to say we don’t actually need all these supposedly essential vitamins and minerals? Actually we do. It is just we are probably using the wrong sources. Millions of people are swallowing vitamin pills each day as part of their “healthy lifestyles.” The multivitamin manufacturing has been a multi-billion industry because most of these “health supplements” are available over the counter without the need of any prescription. Vitamin pills are convenient and easy, can be taken on the go, can fit in the smallest of handbags, don’t spoil, and no need to wash, peel, slice or puree. But are they really the best for us? The abovementioned studies indicate that the answer is “No.”

These are no substitutes for the vitamins and minerals we get from fresh fruits, vegetables and nuts. Nature is still the best source of our nutritional needs.

               

New vaccine strategy reduces prostate cancer treatment side effects

Therapeutic cancer vaccines can help cure prostate cancer patients. However, the technique comes with side effects such as fatigue and increased blood sugar levels that are not well tolerated by many patients. These adverse effects usually lead to the discontinuation of the treatment. New research, however, developed a new strategy to minimize these side effects and thus giving new hope to prostate cancer patients.

Cancer vaccines were developed when researchers discovered that some cancer cells produce some unique proteins in excessive amount. These proteins are unique in a way that they can trigger the immune system to attack the cancer cells. The cancer vaccines were developed by targeting these proteins and stimulate the immune system to attack cancer cells but not the normal cells.

The vaccine for prostate cancer is designed to trigger the immune system to attack prostate-specific antigen (PSA). PSA is a protein produced by the prostate and is found in the blood of men with prostate cancer and non-cancerous conditions. An immune booster called interleukin-2 (IL-2) is normally administered with the vaccine to further boost the body’s natural defense. IL-2, however, brings about the side effects previously described.

“Developing an alternative method of administering vaccine therapy that is well tolerated by most patients and produces similar immune responses to standard methods may help further the development of vaccine therapies for prostate cancer,” according to James L. Gulley of National Cancer Institute’s Center for Cancer Research.

In earlier studies using the same prostate cancer vaccines, IL-2 was given daily for 5 days to 19 patients in every 28-day vaccine treatment cycle. The majority of the patients, however, experiences severe fatigue so that IL-2 was reduced or discontinued.

In the new study led by National Cancer Institute (NCI) researchers, a method called “metronomic dosing” was tested. In this method, 18 patients were treated with vaccine and radiation therapy. The patients were also given the same total amount of IL-2 but were administered daily for 14 days in smaller doses of each 28-treatment cycle. The metronomic dosing showed that less than 25% of the patients experienced side effects that required the reduction of their IL-2 doses. The strategy was found to be safe with fewer side effects but produces similar immune response to the standard dosing method.

“Based on safety and feasibility, metronomic dosing appears to be superior to standard dosing and administration,” said Gulley.

However, more research is needed to evaluate the efficacy of this dosing method in the treatment prostate cancer.”

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