These 17 risk factors are called “modifiable” because people can take active measures to change them. In the new study, such factors included:
- alcohol intake
- smoking (both first- and second-hand)
- excess body weight
- a low content of fibre in one’s diet
- the consumption of processed red meat
- a low intake of fruit and vegetables
- ultraviolet (UV) radiation
- low calcium
- a lack of physical activity
Six infections that have already been linked with cancer were also included among the risk factors.
In their analysis, Dr Islami and his team used not only the prevalence of the risk factors, but also their “associated relative risk” — that is, the probability that said factors actually result in cancer. This information was obtained from “large-scale pooled analyses or meta-analyses.”
Study co-author Dr Otis W. Brawley, ACS chief medical officer, comments on the magnitude of the study, saying, “In 1981, Doll and Peto published what has become a classic paper on the causes of cancer.”
“Since then,” he explains, “volumes of data have been published that have clarified the association between several important risk factors and cancer. In this new report, ACS scientists provide a 21st-century calculation that will guide us in the years ahead.”
Top risk factors: Smoking, weight, alcohol
The study revealed that 42 per cent of all cancers and over 45 per cent of all cancer deaths were down to modifiable risk factors. The top three risk factors were smoking, excessive weight, and alcohol use.
Nineteen per cent of all cancer cases and almost 29 per cent of related deaths were attributable to cigarette smoking. Excess body weight accounted for 7.8 per cent of cases and 6.5 per cent of deaths, while 5.6 per cent of cases and 4 per cent of deaths were down to alcohol intake.
Certain major cancers had a high portion of cases attributable to modifiable risk factors. Lung cancer was at the top, with 85.8 per cent of cases down to such factors, 81.7 per cent of which were attributable to smoking alone.
Additional findings include the fact that UV radiation was linked to 96 per cent of skin melanoma cases, and excess body weight to over 60 per cent of uterine cancers.
Fifty per cent of oesophageal cancers were tied to smoking. Cigarettes were also associated with nearly 47 per cent of bladder cancer cases. Finally, over 10 per cent of colorectal cancers were associated with a low intake of dietary fibre.
‘Knowing about preventive measures’ is key
“These findings underscore the vast potential for reducing cancer morbidity and mortality through broad and equitable implementation of known preventive measures,” conclude the authors.
The study authors remind the public of the four key factors that everyone can keep in check: body weight, alcohol consumption, diet, and physical activity.
The combined influence of these four factors made up nearly 14 per cent of cancer risk in women and over 22 per cent in men.
Dr Islami and colleagues write:
“Our findings emphasize the continued need for widespread implementation of known preventive measures in the country to reduce the morbidity and premature mortality from cancers associated with potentially modifiable risk factors.”
“Increasing access to preventive healthcare and awareness about preventive measures,” the authors conclude, “should be part of any comprehensive strategy for broad and equitable implementation of known interventions to accelerate progress against cancer.”
Source: Medical News Today