Almost 30% of cancer cases that occurred in Ireland in 2016 were potentially preventable, a new report by the National Cancer Registry Ireland (NCRI) has found.

The report focused on modifiable risk factors, such as smoking and being overweight or obese, and found that in 2016, an estimated 29% of cancers - that is over 6,200 cases - were potentially preventable if people's health behaviours had been different.

Furthermore, the NCRI described this as a "conservative estimate" due to a number of reasons. For example, risks associated with occupation were not taken into account, nor was everyday exposure to ultraviolet radiation via sun exposure.

The top two modifiable risk factors when it came to cancer were smoking and being overweight or obese.

Smoking, including passive smoking in the home, accounted for over 2,700 potentially preventable cases in 2016 overall, while being overweight or obese accounted for over 1,000 cases.

"Lung cancer had the highest number of cases attributable to modifiable risk factors in both males and females, followed by colon cancer in males and breast cancer in females," the NCRI noted.

Meanwhile, the report estimated that by 2035, 4,662 cases of cancer will be attributable to smoking, 1,788 will be attributable to overweight and obesity, while 851 will be attributable to alcohol intake.

"Over a 10-year period ending in 2035, it is estimated that a cumulative total of 66,343 cancer cases will be attributable to smoking, overweight and obesity, and alcohol intake,' the report stated.

Other modifiable risk factors included sunburn, a lack of physical activity, processed meat intake and exposure to air pollution.

The NCRI said that public awareness of modifiable risk factors needs to be addressed. For example, recent Irish surveys suggest that just 32% of people are aware that obesity is a risk factor for cancer, while 56% are unaware that HPV infection can cause cancer.

"Several of the risk factors in this report are associated with not only cancer, but a range of other diseases, including heart disease, diabetes and chronic obstructive pulmonary disease. Therefore policies to reduce the prevalence of these modifiable risk factors should consider the wider impact on public health," the report noted.

It stated that future work in this area should examine outcomes, including the impact on mortality and quality of life, while the economic impact of modifiable risk factors should also be considered.

"The economic burden of cancer for the health services, patients and their families, and society at large are substantial. This burden will likely increase in the coming years as novel, more expensive treatments become available and the number of people living with and beyond cancer increases," it added.

The report, Modifiable Risk Factors and Cancer in Ireland, can be viewed here.