Cancer Prevention And Control
Brazil Nuts May Aid Bowel Health
First Published: Enews - August 2011
The results of a human intervention study in Flinders Medical Centre has found a dietary selenium supplement in the form of selenium-enriched milk is showing great promise in preventing bowel cancer.
Selenium is enriched in a few foods such as brazil nuts, some sea foods and the organs of some farm animals including kidneys.
It is possible to fatally overdose on too much selenium, but too little can also have adverse health effects.
While current selenium intake in Australia is sufficient to prevent deficiency diseases, studies have indicated that the typical Australian diet may not contain enough of this essential micronutrient - particular for the elderly, smokers and cancer patients.
As part of the Flinders study, 23 volunteers aged 52-79 years, considered at risk for colon cancer by virtue of their age, were given either selenium-enriched milk or a yeast version of selenium for a period of six weeks.
Regular blood tests found that both sources of selenium were effective in increasing blood selenium levels, but the dairy source of selenium in particular showed positive effects for bowel health.
"The increase in the expression of some selenoprotein genes in the bowel indicates these genes may be involved in protection against certain biological changes, which can cause colon cancer," Dr Ying Hu, who has been managing the study, said.
These results were published in the British Journal of Nutrition in March 2011.
"We would now like to undertake a longer study to encompass the effect of selenium supplementation on other changes in the bowel such as the recurrence of polyps," Dr Hu said.
The team hope that if the results are proven over the longer term, then new selenium enriched foods may be developed to improve bowel health and help prevent colon cancer.
Ignorance Drives Radiation Fears
First Published: Flinders Journal - June 2011
The possibility that low doses of radiation may prevent or delay the progression of cancer is being explored by a Flinders University research team led by Professor Pam Sykes in a move that runs counter to the widely held perception that exposure to any radiation is harmful.
Professor Sykes, recently appointed to the University’s Strategic Professorship in Preventive Cancer Biology in the Flinders Centre for Cancer Prevention and Control says the public panic in response to nuclear accidents such as that at Fukushima in Japan is the result of a general ignorance about radiation.
“We have to ensure that radiation is respected and we have to understand what damage radiation can cause – but radiation is not the poison, the dose is,” Professor Sykes said.
“We need radiation in our environment, just as we need vitamins and minerals. Too much is a problem, too little is a problem,” she said.
“Chernobyl was obviously a disaster but there was no increase in leukaemia, solid tumours or birth defects among the 335,000 people who were evacuated and who received less than 100 milliSieverts of radiation – that’s five times the dose I’m allowed as a radiation worker.
“There was an increase in thyroid tumours but we’re not sure how much that related to the fact that everyone was screened for thyroid tumours, which wouldn’t normally happen.
“It’s now been accepted that they should not have evacuated so many people because the biggest detriment from Chernobyl was that they were dramatically disadvantaged, both economically and socially. Many suffered depression thinking they were going to die of cancer.
“And the frightening thing is that it’s been estimated that throughout Europe there were over 100,000 wanted pregnancies aborted, and these were people who didn’t live anywhere near Chernobyl.”
Professor Sykes’ research, which involves doses of radiation that are up to three orders of magnitude lower than those used by other investigators, has been funded by the US Department of Energy Low Dose Radiation Research Program for almost 10 years.
“Using a transgenic mouse that is very sensitive to stressors, we have identified regions in the dose range that cause different biological effects,” she said.
“Some of our colleagues in Germany and Oxford have shown that low doses of radiation to cells in culture trigger a mechanism which removes pre-tumour cells. We’re now working to see if we can identify this response in a mouse.
“If we can understand these mechanisms, we can manipulate them to prevent cancer,” adding it might be “several years” before the potential to humans could be confirmed.
Studies in Canada and Japan have also shown that low doses of radiation given to mice delay the onset of cancer, and reduce the symptoms of diabetes and atherosclerosis, improving the span and quality of life of the affected animals.
Professor Sykes and her team are currently examining low dose radiation therapy in reducing or preventing prostate cancer, with a grant from the Prostate Council Foundation of Australia.
Resistant Starch Balances Red Meat Risks
First Published: Investigator - July 2009
Updated: July 2011
Flinders researchers are studying the potential role of a dietary fibre supplement in reducing the risk for bowel cancer in people who consume a diet rich in red meat.
‘The aim of the study is to ascertain whether the consumption of a diet high in red meat causes changes in certain markers for bowel cancer, and whether adding resistant starch to the diet can improve these effects,’ Flinders Cancer Prevention and Control researcher Dr Richard Le Leu, said.
23 participants in the study were asked to consume 300 grams of either beef or lamb daily for a total of eight weeks, interspersed with lower-meat periods. During one of the 4-week red meat phases of the study they were required to take a daily fibre supplement that is high in resistant starch.
‘Scientists have long suspected that a diet high in red meat may contribute to a greater risk of developing bowel cancer. What we want to determine is whether the addition of a resistant starch supplement may help counter this risk,’ Dr Le Leu said.
He said it would be good news for many Australians if it did. ‘Australia has a high consumption of red meat compared to many countries in the world, and we also have a high incidence of bowel cancer. Anything that could reduce that risk would be welcome.’
To date, the Flinders research team, working in conjunction with researchers from the CSIRO, have successfully completed all the volunteer dietary interventions. The samples that were collected (rectal biopsies, blood, faeces and urine) are currently being analysed for bowel cancer risk and protective factors.
Improving Screening For Inherited Cancers
First Published: Investigator - August 2008
Important research at Flinders has continued to make inroads into inherited breast and ovarian cancers thanks to a $16,000 contribution from Angela Condous and the Advertiser and Sunday Mail Foundation (ASMF).
Dr Scott Grist and his team are developing a cost-effective pre-screening laboratory test to better identify individuals who may carry a harmful BRCA1 or BRCA2 gene defect.
The BRCA genes are responsible for repairing DNA damage in a cell. If a defect is inherited in one or both genes there is a 60-80% chance that breast or ovarian cancer will develop as DNA damage accumulates over time.
“Approximately 20% of those screened carry DNA variants that cannot be easily identified as those that cause cancer,” said Dr Scott Grist, Head of the Inherited Cancer Genetics Lab at Flinders Medical Centre.
“This represents a large group of individuals with an uncertain diagnosis who are not benefiting from the testing and who are put under additional psychological stress.”
The current screening method is also quite costly, limiting it to those who know they have a strong family history of breast and ovarian cancer.
Using a technique that screens for DNA damage, this test can measure the rate of DNA repair of a possible BRCA gene defect carrier against the rate of repair from a healthy BRCA gene sample.
This will identify if a full screening of the BRCA genes is required, both saving un-necessary and extensive screening and easing the minds of those who don’t know their family’s medical history or have an unknown defect in a BRCA gene.
The ASMF will hold another fundraising lunch on 27 August 2008 to continue raising funds for breast cancer research at Flinders. Contact the Flinders Medical Centre Foundation on (08) 8204 5216 for more information or to book tickets.
Bowel Cancer Study
First Published: Investigator - February 2008
Updated: Brazil Nuts May Aid Bowel Health
Researchers are seeking people to take part in a study to test the effectiveness of two different selenium supplements which may improve bowel health.
Selenium might not be available in adequate amounts in the diet of Australian people. It is enriched in a few foods such as brazil nuts, some sea foods and the organs of some farm animals including kidneys.
The study will examine the benefits to bowel health of a selenium-enriched dairy milk product and a selenium yeast product. Both products are prepared naturally by feeding selenium supplements to dairy cows.
Professor of Gastroenterology at Flinders Medical Centre and Flinders University. Graeme Young said blood levels of selenium in Australians are barely adequate by international standards which is why dietary supplements could be important in improving bowel health and therefore reducing the risk of bowel disease.
Study participants will consume either the milk or yeast product for a period of six weeks with a follow-on monitored six week period without the selenium product. Blood tests and effects on bowel health will be assessed regularly during each period. 4711.
Volunteers aged greater than 50 years who are interested in taking part in the study can contact Gastroenterology Research Nurse Libby Bambacas on 8204 5534. Entry criteria does apply.
Screening For Inherited Breast And Ovarian Cancers
First Published: Investigator - April 2007
Thanks to money raised at the Pink Ribbon Ball a more sensitive and accessible test to screen for hereditary breast and ovarian cancer is currently being devised by scientists at Flinders Medical Centre.
Dr Scott Grist, Head of the Inherited Cancer Genetics Lab, and his team are focusing on perfecting a technique that can simplify screening for genetic defects within the BRCA1 and BRCA2 genes.
BRCA1 and BRCA2 are tumour suppressors involved in repairing DNA breaks within cells. If a defect is inherited in these genes there is an 80-90% chance that breast or ovarian cancer will develop. Inherited BRCA gene defects are also the leading risk factor for male breast cancers.
“The BRCA genes are important as they are central to DNA repair,” said Dr Grist. “DNA in our cells is damaged all the time. If you have a defect in the BRCA genes this damage cannot be fixed which leads to an accumulation of mutations that often result in cancer.”
Currently screening patients for these defects is costly and time consuming as the BRCA genes are quite large. This test is also limited to families with a proven history of cancer, unless individuals wish to spend the money required to undergo the screening.
It has been found that if there is a defect within these BRCA genes, double strand DNA breaks repair slower than they normally would. The team are working toward a sensitive way to measure how different this rate of DNA break repair is compared to when the BRCA genes are healthy.
Once this is discovered it will be much simpler to test a patient’s blood and see if the rate of repair indicates that there is a BRCA1 or BRCA2 defect. This will allow those with a family history of cancer to be screened much quicker and more cost effectively to identify if a full screen of the BRCA genes is required. Making this information much more accessible to those who think they may be at risk.
“The test will enable us to quickly screen larger numbers of people,” said Dr Grist. “If we find a gene defect in a familial cancer patient we can then do a simple screening on all family members to inform them if they carry the same gene defect or not.”
This test is still being fine tuned however once it is ready for use it will be a vital tool for those with a familial history of breast or ovarian cancer, to ease minds or prepare individuals for the possibility of cancer.
Screening Program Sends a Lifeline To Luke
First Published: Investigator - April 2005
Luke Sincock would have never have thought at 22 years of age he was in the high-risk category for bowel cancer.
With a long and detailed family history of bowel cancer involving around 40 family members, Luke was recently delivered a lifeline when a screening program detected early signs of bowel cancer.
The Southern Cooperative Program for the Prevention of Colorectal Cancer (SCOOP) at the Flinders Medical Centre is the brainchild of Professor Graeme Young, a leading researcher in the field, and Dr Peter Bampton, Head of Endoscopy.
“The chances of more than one family member having bowel cancer currently stands at between two to three per cent, so the Sincock family’s situation is extremely rare,” Professor Young said.
“The aim of SCOOP is to ensure that those at high risk of developing bowel cancer have the appropriate tests done at the right time, and then have them repeated at the right interval. We do not want people to forget or be forgotten.
“If the majority of the population were to participate in screening using existing simple stool test technologies, within ten years the death rate from bowel cancer alone would be reduced by 40 per cent.
Professor Young said that in the context of a family risk for bowel cancer, colonoscopies traditionally take place every three to five years, allowing staff to detect abnormalities by viewing the inside of the intestine using a microscopic camera. Occasionally people require colonoscopies more frequently.
“We’ve further enhanced the screening program by introducing a home testing kit, known as faecal immunochemical test (FIT) for the 4,000 or so people currently involved in the program to carry out in between colonoscopies,” he said.
Professor Young says the home test can be used for the general population for screening, or for people with a family history in between colonoscopies.
“This allows us to detect certain abnormalities in the bowel, namely pre-cancerous polyps or early cancers, to be picked up in the curable stages. It is a more discreet and less obtrusive way of checking which reassures both the individual and the clinicians.” .
As an Australian-first, the SCOOP program has already proven to be highly successful and is attracting attention from hospitals around the country.
In his role as Director of Development for the proposed $14.5 million Flinders Centre for Innovation in Cancer, Professor Graeme Young says the Centre will focus on all aspects of prevention, and the SCOOP program is just one example of the type initiative that will be part of this Centre.
Beans Means Healthy Bowels!
First Published: Investigator - October 2004
Next time you shop at the supermarket, pick up a can of baked beans because they could be the key to reducing your bowel cancer risk.
A new study at Flinders has confirmed foods high in resistant starch, such as baked beans, rice and pasta, can improve bowel health and reduce the risk of bowel cancer, the most frequently occurring cancer in Australia today.
Most foods are digested in the small intestine but resistant starch resists digestion in the small intestine and reaches the bowel. In the bowel, it is fermented by bacteria, which produce short chain fatty acids. The fatty acids provide a source of energy for colon cells and are proven to be an effective anti cancer agent.
Professor of Gastroenterology at Flinders Medical Centre and Flinders University Graeme Young and Research Fellow Dr Richard Le Leu recently conducted the study using a product high in resistant starch called Hi-Maize® - a food ingredient made from specially bred Australian corn.
The study showed a 30 percent increase in the death of potentially cancerous cells in the colon when the diet included more than 20 percent Hi-Maize.
Death of genetically damaged cells occurs through an automatic biological function called apoptosis. Without apoptosis, the genetically damaged cells could multiply and develop into colorectal cancer. A diet high in resistant starch increases the apoptotic response and may reduce the risk of developing bowel cancer.
A 10 percent Hi Maize diet supplemented with probiotics has also been found to increase apoptotic response. Probiotics are a food ingredient commonly found in yoghurt and fermented milk drinks that deliver external ‘friendly’ bacteria to the gut.
Professor Young and Dr Le Leu now plan to test the resistant starch and combined starch probiotic diet for their effect on colonic tumour development.
Bowel Cancer Survey Helps To Save Lives
First Published: Investigator - February 2003
Last year Professor Graeme Young from Flinders Medical Centre's Department of Gastroenterology launched a study of community attitudes in both men and women towards bowel cancer screening. We are now pleased to report the following outcomes from Professor Young's research.
"What we have learnt from the survey will now assist us in providing a more acceptable screening program while also ensuring that proper marketing campaigns regarding the necessity of screening can be developed.
"The program was initially set up to examine barriers that stop people from being screened, for example why will some people be tested when others will not." said Professor Young."
The survey showed that some people will not be screened as they cannot see the value in being tested or don't believe that the test will work. The survey also addressed the issue of trust when it comes to patients being encouraged to take the test, with patients more likely to agree if their general practitioner suggests it rather than a family member or friend.
"This finding will help us work more closely with general practitioners to make them encourage patients in the bowel cancer age range to participate in screening.
"Most bowel cancer develops from polyps, but not all polyps are cancerous. Picking up the early signs of bowel cancer means it can be effectively treated." Said Professor Young.
The next stage of Professor Young's research will involve a $7 million dollar pilot study. Funded by the Federal Government it will screen over the next 18 months, 23,000 men and women aged between 55 and 74 years in nine southern district postcode regions in Adelaide.
If the study is successful it will lead to a national screening program aimed at picking up the early signs of the disease.
If you are over 50, or have a family history of bowel cancer or past bowel problems, then you should contact your general practitioner and ask to be screened.