Large, Long-term Study Suggests Link Between Eating Mushrooms and A Lower Risk of Prostate Cancer

Results from the first long-term cohort study of more than 36,000 Japanese men over decades suggest an association between eating mushrooms and a lower risk of prostate cancer.

Their findings were published in the International Journal of Cancer.

Prostate cancer begins when cells in the prostate gland — a small walnut-shaped gland found only in men, which produces the fluid that forms part of the semen — start to grow out of control. It is one of the most common forms of cancer affecting men, with over 1.2 million new cases diagnosed worldwide in 2018, the risk increasing with age.

Mushrooms are widely in used in Asia, both for their nutritional value and medicinal properties.

“Test-tube studies and studies conducted on living organisms have shown that mushrooms have the potential to prevent prostate cancer,” said Shu Zhang, an assistant professor of epidemiology in the Department of Health Informatics and Public Health at Tohoku University School of Public Health, Graduate School of Medicine in Japan, and lead author of the study.

“However, the relationship between mushroom consumption and incident prostate cancer in humans has never been investigated before.”

“To the best of our knowledge, this is the first cohort study indicating the prostate cancer-preventive potential of mushrooms at a population level,” said Zhang. “Although our study suggests regular consumption of mushrooms may reduce the risk of prostate cancer, we also want to emphasize that eating a healthy and balanced diet is much more important than filling your shopping basket with mushrooms.” said Zhang.

For this study, the researchers monitored two cohorts consisting of a total of 36,499 men between the ages of 40 and 79 years in Miyagi and Ohsaki, Japan, from 1990 and 1994 respectively. The follow-up duration for the Miyagi cohort extended from June 1, 1990 to December 31, 2014 (24.5 years), while the follow-up duration for the Ohsaki cohort extended from January 1, 1995 to March 31, 2008 (13.25 years). The men were asked to complete a questionnaire related to their lifestyle choices, such as mushroom and other food consumption, physical activity, smoking and drinking habits, as well as provide information on their education, and family and medical history.

Long-term follow-up of the participants indicated that consuming mushrooms on a regular basis reduces the risk of prostate cancer in men, and was especially significant in men aged 50 and older and in men whose diet consisted largely of meat and dairy products, with limited consumption of fruit and vegetables. Statistical analysis of the data (using the Cox proportional hazards model) indicated that regular mushroom consumption was related to a lower risk of prostate cancer regardless of how much fruit and vegetables, or meat and dairy products were consumed. Of the participants, 3.3% developed prostate cancer during the follow-up period. Participants who consumed mushrooms once or twice a week had an 8% lower risk of developing prostate cancer, compared to those who ate mushrooms less than once per week, while those who consumed mushrooms three or more times per week had a 17% lower risk than those who ate mushrooms less than once a week.

According to Zhang, “mushrooms are a good source of vitamins, minerals and antioxidants, especially L-ergothioneine” — which is believed to mitigate against oxidative stress, a cellular imbalance resulting from poor diet and lifestyle choices and exposure to environmental toxins that can lead to chronic inflammation that is responsible for chronic diseases such as cancer.

“The results of our study suggest mushrooms may have a positive health effect on humans,” said Zhang. “Based on these findings, further studies that provide more information on dietary intake of mushrooms in other populations and settings are required to confirm this relationship.”

“Considering the average American consumes less than 5 grams of mushrooms per day, which is lower than that consumed by the participants in this study (7.6 g/day) one would expect that even a small increase in mushroom consumption to offer potential health benefits,” said Zhang.

Source: Tohoku University School of Public Health


Radiation Right After Surgery Might Not Help Prostate Cancer Patients

In the largest investigation of its kind, researchers conclude that subjecting prostate cancer patients to radiation therapy immediately after surgery doesn’t give them an advantage in staying cancer-free.

The finding stems from a review of four studies that together tracked outcomes for more than 3,500 prostate cancer patients from multiple countries.

If the findings help change standard practice, “the good news is that, in future, many men will avoid the side effects of radiotherapy,” said study first author Chris Parker, of the Institute of Cancer Research in London.

His team was to present its findings Friday at the European Society for Medical Oncology annual meeting, in Barcelona.

Parker stressed that radiation side effects can be troublesome. They “include urinary leakage and narrowing of the urethra, which can make urination difficult,” he said in a meeting news release. “Both are potential complications after surgery alone, but the risk is increased if radiotherapy is used as well.”

Curbing cancer’s spread

One prostate cancer specialist explained why doctors have often ordered radiation for patients who’ve undergone prostate removal (prostatectomy).

“Many men that undergo radical surgery for prostate cancer may have a spread of the disease beyond the capsule of the prostate, or invasion [of the tumor] into the seminal vesicles or lymph nodes,” said Dr. Louis Potters, deputy physician-in-chief at Northwell Health Cancer Institute, in Lake Success, N.Y.

“These factors occur in about 30% of men having surgery,” said Potters, who wasn’t involved in the new trial. The post-op radiation is meant to “mop up” potential cancer cells that may have spread beyond the prostate.

“Several randomized controlled studies with long-term follow-up conclude that earlier use of radiotherapy is better than delayed radiotherapy to control the disease,” Potters noted.

But according to Parker’s group, the new trial is one of the largest such investigations into the issue, involving nearly 1,400 men who’d undergone prostatectomy. After their operation, the men were randomly assigned to one of two groups. One group got radiation right away, while the other was treated with a “watch-and-wait” approach and only got radiation if the cancer returned.

Outcomes for both groups were monitored closely for five years.

Parker’s team found that when it came to the risk of cancer’s return, there was essentially no difference between the two groups. The trial found that 85% of men in the immediate-radiation group were free of cancer five years after their surgery, compared with 88% among the men whose radiation was either delayed or never ordered.

There was a big difference in terms of unwanted side effects, however: while 5.3% of men who got post-surgical radiation said they suffered from urinary incontinence during the year after the treatment, that number fell to 2.7% among men in the “watch-and-wait” protocol.

Delaying might be better

A second analysis pooled the results of three other studies, which in total involved about 2,150 men. That study also found just a 1% difference in five-year survival rates between the radiation and no-radiation groups.

Taken together, the results suggest that prostate cancer patients can safely forgo immediate post-surgical radiation — as well as the side effects radiotherapy can bring, Parker said.

“The results suggest that radiotherapy is equally effective whether it is given to all men shortly after surgery or given later to those men with recurrent disease,” said Parker, who is also with The Royal Marsden NHS Foundation Trust. “There is a strong case now that observation should be the standard approach after surgery, and radiotherapy should only be used if the cancer comes back.”

The case may not be completely closed on this issue, however. The London team suggested that continued research is needed to track disease-progression rates for a full 10 years.

Case-by-case approach

For his part, Potters agreed that the five-year follow-up is still too short a time to justify a definitive change in practice. But he said that, already, U.S. physicians are often backing away from giving all patients radiation immediately after prostatectomy. Instead, they are making decisions based on tumor type and other factors.

And Potters said that ongoing advances in genetic testing “may ultimately best determine who most needs early post-operative radiotherapy.”

Dr. Lee Richstone is chairman of urology at Lenox Hill Hospital in New York City. Reviewing the new data, he agreed that the practice of giving patients immediate post-op radiation has been “controversial,” and the U.K. study might lay the controversy to rest.

“The results suggest there is no benefit to immediate radiation, and patients can be safely watched,” Richstone said. “This is important because it helps to prevent thousands of patients from getting radiation that they may not need, and radiation can have toxic side effects in some men,” he added.

“More research is needed,” Richstone said, “but this data supports what I do for the patients I operate on. Most are observed without radiation, unless they have multiple high-risk features and the benefits of radiation outweigh the risks.”

Because the new findings were presented at a medical meeting, they should be considered preliminary until published in a peer-reviewed journal.

Source: HealthDay

Today’s Comic

Prostate Cancer Prevention with Proper Nutrition

Christopher R. Mohr wrote . . . . . . . . .

Did you know that, not counting some forms of skin cancer, prostate cancer is the most common cancer in American men? In the United States, one in nine men will be diagnosed with prostate cancer during the course of their life. There is no way to know for sure if you will get prostate cancer, and men have a greater risk of prostate cancer if they are 50 years old or older, are African-American, or have a father, brother or son who has had prostate cancer.

Can You Reduce the Risk?

While it’s recommended that men discuss the benefits and risks of prostate cancer screening with their doctors, there’s also the question if there’s a way to reduce the risk of developing prostate cancer in the first place. Lycopene, vitamin E and selenium are marketed to men as tools to reduce the chance of developing the disease. But is supplementation beneficial? Can eating specific foods help?

Most experts agree that men should get the recommended amounts of selenium and lycopene from foods rather than supplements. A general, healthful eating pattern contains both selenium and lycopene which are naturally available in a variety of foods. Eating plentiful vegetables, fruits, beans, whole grains, nuts and seeds contributes to overall health, including reducing risk of many types of cancer.

No Magic Bullet

Steer clear of supplements or foods that are touted as “magic bullet” prevention tools. In fact, some research has emerged showing high levels of certain nutrients taken as supplements — including vitamin E — may actually increase risk. However, there are some actions men can take to still get these beneficial nutrients to help them stay healthy.

  • Aim to eat 2½ cups of vegetables and 2 cups of fruit per day. Choose dark-colored fruits and vegetables more often. Dark colored produce, such as spinach, berries and orange bell peppers, have higher levels of many carotenoids and other healthful nutrients. Individually, these nutrients may not play a major role in prostate cancer prevention. However, when obtained from foods, these nutrients work with one another to promote health.
  • Replace less healthy, saturated and trans fats with their healthy alternatives from plant foods — olive oil, canola oil, avocados and unsalted nuts.
  • Be physically active. Research has shown that men who had prostate cancer and engaged in physical activity had a lower risk of dying from the disease. For substantial health benefits, the 2018 Physical Activity Guidelines recommend that adults engage in a minimum of 30 minutes of moderate-intensity physical activity at least five times a week.

Source: Academy of Nutrition and Dietetics

Today’s Comic

New Blood Test for Prostate Cancer Is Highly-accurate and Avoids Invasive Biopsies

In combination with the current prostate specific antigen (PSA) test, the new test could help men avoid unnecessary and invasive biopsies, over-diagnosis and over-treatment.

Prostate cancer is the most common cancer in Western men, with 1.3 million new cases being diagnosed each year worldwide. It is currently detected using a blood test that measures PSA levels. Although it provides early diagnosis, the PSA blood test has a low specificity (high false positives) with about 75 per cent of all PSA positive results ending up with negative biopsies that do not find cancer.

When a high PSA level in the blood is detected, the patient undergoes a tissue biopsy of the prostate gland, which is invasive and carries a significant risk of bleeding and infection. On biopsy, the majority of patients with elevated PSA levels are found not to have cancer.

Additionally, most diagnosed early-stage prostate cancers are not fatal if left untreated. The current practice of the combined PSA test and biopsy for prostate cancer therefore results in unnecessary biopsies and over-diagnosis and overtreatment of many men.

Circulating tumor cells

The new prostate cancer test (the Parsortix® system from ANGLE plc) detects early cancer cells, or circulating tumor cells (CTCs), that have left the original tumour and entered the bloodstream prior to spreading around the body. By measuring intact living cancer cells in the patient’s blood, rather than the PSA protein which may be present in the blood for reasons other than cancer, it potentially provides a more accurate test for prostate cancer.

The study, published in the Journal of Urology, looked at the use of the CTC test in 98 pre-biopsy patients and 155 newly diagnosed prostate cancer patients enrolled at St Bartholomew’s Hospital in London.

The research team found that the presence of CTCs in pre-biopsy blood samples were indicative of the presence of aggressive prostate cancer, and efficiently and non-invasively predicted the later outcome of biopsy results.

When the CTC tests were used in combination with the current PSA test, it was able to predict the presence of aggressive prostate cancer in subsequent biopsies with over 90 per cent accuracy, better than any previously reported biomarkers.

Additionally, the number and type of CTCs present in the blood was also indicative of the aggressiveness of the cancer. Focusing on more aggressive prostate cancer may reduce over-treatment and unnecessary biopsies for benign and non-aggressive conditions.

‘A paradigm shift in the way we diagnose prostate cancer’

Lead researcher Professor Yong-Jie Lu from Queen Mary’s Barts Cancer Institute said: “The current prostate cancer test often leads to unnecessary invasive biopsies and over-diagnosis and overtreatment of many men, causing significant harm to patients and a waste of valuable healthcare resources. There is clearly a need for better selection of patients to undergo the biopsy procedure.

“Testing for circulating tumour cells is efficient, non-invasive and potentially accurate, and we’ve now demonstrated its potential to improve the current standard of care. By combining the new CTC analysis with the current PSA test, we were able to detect prostate cancer with the highest level of accuracy ever seen in any biomarker test, which could spare many patients unnecessary biopsies. This could lead to a paradigm shift in the way we diagnose prostate cancer.”

As this is a single centre study, the results need to be further validated in other independent research centres before the CTC test is available either privately or on the NHS in the UK, which could take a further 3-5 years. Clearance by the US Food and Drug Administration could also take 3-5 years.

Source: Queen Mary University of London

Today’s Comic

Gold Nanoparticles Used in Photothermal Therapy Shown to be Safe and Effective Treatment for Prostate Cancer

Biocompatible gold nanoparticles designed to convert near-infrared light to heat have been shown to safely and effectively ablate low- to intermediate-grade tumors within the prostate, according to a study conducted at the Icahn School of Medicine and published in the journal Proceedings of the National Academy of Sciences. This treatment could offer patients a targeted therapy option that would preserve critical structures within the prostate, thus avoiding side effects associated with whole-gland treatment such as prostatectomies.

Prostate cancer is the second leading cause of cancer deaths in men in the United States¾11 percent of men will be diagnosed with the disease in their lifetime. Removal or other whole-gland treatment of the prostate carries risks of urinary incontinence and erectile dysfunction. However, technological advances have provided clinicians with options for focal therapies with fewer complications.

In this study, researchers tested the effectiveness of AuroLase® Therapy, a treatment from medical device company Nanospectra Biosciences that is based on technology invented at Rice University by engineer and chemist Naomi Halas, PhD, and Duke University bioengineer Jennifer West, PhD. The Principal Investigator and lead author, Ardeshir Rastinehad, DO, Associate Professor of Urology, and Radiology, at the Icahn School of Medicine at Mount Sinai, invented the technique used in the clinical trial to target and treat the prostate cancer cells using a custom-built MR US fusion guided platform in collaboration with Philips Healthcare. AuroLase® uses gold-silica nanoshells (GSN), particles Dr. Halas invented that are composed of a silica core and a gold shell with a diameter of 150 nanometers. AuroShells® are designed to absorb energy from near-infrared light and convert it to heat, resulting in selective hyperthermic cell death, without affecting adjacent non-tumorous tissue. The treatment was effectively demonstrated in previous cell studies and animal models. Following treatment, the particles are cleared through the liver, while some remain sequestered in the liver and spleen. There are no known side effects.

Sixteen men aged 58 to 79 with low- to intermediate-grade prostate cancer (Gleason score of 4+3) received GSN infusion. All were diagnosed and treated at The Mount Sinai Hospital using a targeted biopsy technique called magnetic resonance-ultrasound fusion imaging, which uses MRI technology to extract a tissue sample directly from the tumor. Patients underwent GSN infusion and high-precision laser ablation, and received an MRI of the prostate 48-72 hours after the procedure, MRI-targeted fusion biopsies at 3 and 12 months, and a standard biopsy at 12 months. Patients were discharged on the same day as the procedure after several hours of monitoring.

GSN-mediated focal laser ablation was successful in 87.5 percent of lesions treated at one year of follow-up. The goal of researchers was to find an eradication of cancer cells during biopsy.

“Gold-silica nanoshells infusion allows for a focused therapy that treats the cancer, while sparing the rest of the prostate, thus preserving a patient’s quality of life by reducing unwanted side effects, which could include erectile dysfunction and/or the leakage of urine,” said Dr. Rastinehad.

“Mount Sinai’s interventional urology program is research-driven and offers patients minimally invasive treatment therapies that improve quality of life,” said Ash Tewari, MBBS, MCh, Chair of the Department of Urology at the Mount Sinai Health System and the Kyung Hyun Kim, MD Professor of Urology at the Icahn School of Medicine at Mount Sinai. “Dr. Rastinehad’s gold nanoparticle research shows that patients are not only benefiting from this treatment, but also experiencing minimal side effects.”

Source: Mount Sinai