People are too often placing undue emphasis on factors like stress and pollution as causes of cancer ahead of real risks like drinking and obesity, Cancer Council NSW says.
A study by the organisation of 3,000 people found they were often confused about what exactly caused cancer.
Many of those surveyed were able to successfully identify well-known risk factors like smoking, sunburn and family history.
However, others put too much weight on things like chemicals in foods, pollution and stress — factors for which there was no strong evidence of increased cancer risk.
Not enough of those surveyed identified proven risk factors like being overweight, a lack of exercise, drinking alcohol and eating processed meats.
Cancer programs director Kathy Chapman said people were more likely to blame cancer on factors they could not control than those they could.
This was a concern because people would not change their lifestyle to improve their health.
“There’s good community understanding that smoking and sunburn are risk factors,” she said.
“Then the next lot of things that people think of are not actually things to worry about, like pollution and stress.”
She said one-third of cancers were preventable.
Drinking alcohol daily increases the risk of head and neck, breast and liver cancers.
Being overweight and obese is linked to cancer of the breast, bowel, endometrium and oesophagus.
“We do know people often will be more likely to blame cancer on factors that are not within their control, rather than recognise the steps that they can take to protect themselves,” Ms Chapman said.
“And being a healthy weight, [having] a healthy diet and being active are certainly really important steps to lower our rates of cancer.”
Ms Chapman said more education was needed.