Reducing the risk of cancer in a large percentage of cases can be prevented just by making 17 necessary lifestyle changes, a new study says.
According to researchers at the American Cancer Society, four in 10 cancer cases and deaths in the U.S. are associated with these “major modifiable risk factors,” many of which can easily be eliminated.
The study looked at 1,570,975 cancer cases with 26 cancer types, 587,521 of which resulted in death.
Researchers used the prevalence of known risk factors and their relative risk (the probability that says the factors actually cause cancer) to estimate the proportion of cancers due to these factors. Then they applied those to actual cancer data to estimate the number of associated cancer cases and deaths overall.
What researchers found was that 42 per cent of all cancers and 45 per cent of all cancer deaths were down to these 17 “modifiable” risk factors: smoking, exposure to second-hand smoke, excess body weight, alcohol intake, eating red meat, eating processed meats, low fruit and vegetable intake, low dietary fibre intake, low calcium consumption, lack of physical activity and exposure to UV radiation.
Six infections were also among the list of risk factors, they include helicobacter pylori, hepatitis B virus, hepatitis C virus, herpes, HIV and HPV.
“Our findings emphasize the continued need for widespread implementation of known preventative measures…to reduce the morbidity and premature mortality from cancers associated with potentially modifiable risk factors,” the authors said in a statement. “Increasing access to preventative health care and awareness about preventative measures should be part of any comprehensive strategy for broad and equitable implementation of known interventions to accelerate progress against cancer.”
Cigarette smoking accounted for the highest proportion of cancer cases, the study found (19 per cent) and deaths (about 29 per cent). This is followed by excess body weight (about eight per cent of cases and seven per cent of deaths), alcohol intake (about six per cent of cases and four per cent of deaths), UV radiation (about five per cent of cases and two per cent of deaths) and lack of physical activity (about three per cent of cases and two per cent of deaths).
Lung cancer was also found to have the highest number of cancer cases and death, followed by colorectal cancer.
The study was published in the journal CA: A Cancer Journal for Clinicians.
In Canada, one in two people are expected to be diagnosed with cancer in their lifetime, according to the Canadian Cancer Society.
Canadians, however, have the power to reduce their cancer risk, the society says.
“This report underscores how important it is to focus on healthy behaviours and healthy public policies to reduce the number of people hearing the words ‘you have cancer’ each year,” Dr. Leah Smith, an epidemiologist at the Canadian Cancer Society, said in a statement. “Actions like quitting smoking, eating well, being physically active and practicing sun safety, along with appropriate cancer screen tests, can go a long way to reducing your risk of getting cancer.”
For men, the lifetime risk is 49 per cent and women 45 per cent.