Study suggests ways to cut bowel cancer numbers
Healthier lifestyles could reduce the incidence of bowel cancer in Australia by 45,000 over the next decade.
Newly published research that pooled data from seven cohort Australian studies, involving almost 370,000 people aged 18 and over, has found that a large portion of bowel cancers are preventable through the adoption better lifestyle choice.
The study by researchers from UNSW’s Centre for Big Data Research in Health has found that current rates of smoking, obesity and excessive alcohol consumption could lead to 45,000 cases of bowel cancer over the next 10 years.
The results, first published in JNCI Cancer Spectrum, have implications for public health education, promotion and policy.
UNSW Associate Professor Claire Vajdic said the researchers examined the factors causally associated with developing bowel cancer and their current distribution in the Australian population.
They found that 11 per cent of the future bowel cancer burden can be attributed to ever-smoking, and four per cent to current smoking.
Overweight or obesity was responsible for 11 per cent of cases, and excessive alcohol consumption contributed six per cent of the burden.
“We then explored what this means for the future bowel cancer burden in Australia, and where we should be targeting our health promotion efforts,” Prof Vajdic said.
“Combined, these factors will be responsible for one in four future bowel cancers – even more so for men – 37 per cent of bowel cancers – than women – 13 per cent.
“If people changed their behaviours accordingly, a large proportion of this future burden could be avoided.”
The study is the first to identify subgroups within the population with the highest burden.
The patterns were due to differences in both the prevalence of these lifestyles – both factors are more common in men – and the strength of the association between the lifestyle factors and bowel cancer risk.
“We found that more bowel cancers were caused by overweight or obesity and excessive alcohol consumption in men than in women,” Prof Vajdic said.
“Hormones and differences in body fat distribution, particularly excessive fat around the stomach, likely contribute to the higher body fatness-related risk in men. We also know that men drink more alcohol than women, which increases their bowel cancer risk.”
The researchers also found an interesting interplay between smoking and alcohol: the bowel cancer burden attributable to smoking was significantly exacerbated by excessive alcohol consumption, and vice-versa.
This means that the future bowel cancer burden would be markedly lower if current and former smokers did not drink excessive alcohol. The study results have important public health implications.
The findings can inform both general and targeted education, public policy, health literacy and health promotion campaigns aimed at reducing cancer incidence and maximising early detection.
Prof Vajdic said the results suggest education efforts may need to be especially directed towards current and former smokers, given their increased burden.
The results can also be translated into a number of health recommendations.
“We know that smokers are less likely to participate in our National Bowel Cancer Screening Program, so they are a particularly vulnerable group,” she said.
“Our findings make a case to support everybody – but men in particular – to achieve and maintain a healthy weight to prevent bowel cancer.”
The current Australian recommendations for healthy living are to not smoke, to do at least 150 minutes of moderate or 75 minutes of vigorous physical exercise per week, to maintain a healthy weight (BMI 18.5 – 25 kg/m2), to drink fewer than two alcoholic drinks per day, to not eat more than 65 grams of red meat per day, and to keep processed meat consumption to a minimum.
Research collaborator and Cancer Voices South Australia representative, Julie Marker, has survived bowel cancer three times over the past 17 years.
“Any action you can take to prevent or detect bowel cancer early might save you from the battle I’ve had,” she says.
“I’d encourage men and women – but especially men – to adopt a healthy lifestyle and participate in bowel cancer screening to reduce their risk. GPs and other health professionals should target prevention and screening advice to their patients, using insights from this research.”