At least half of US cancer cases and deaths are caused by avoidable factors like smoking, eating processed meat and physical inactivity, a new American Cancer Society report reveals.

These graphs lay bare which lifestyle factors are the riskiest, and how much they affect your cancer risk, according to the study - with cigarette smoking easily the most dangerous activity.

They also reveal how some lifestyle habits are more risky for men than women, and vice versa.

Notably, cigarettes and processed or red meat and alcohol carry a much higher cancer risk for men than women, while women should be more wary of excess body weight than men.

How lifestyles affect your cancer risk - based on gender: This graph shows how cigarette smoking, alcohol, processed meat and low fruit and vegetable intake is riskier for men than women. For women, excess body weight, physical inactivity, low fiber and HPV are riskier

Dr Farhad Islami, MD, of the American Cancer Society, compiled a comprehensive list of known risk factors, and how risky each one is, based on previously-published data.

His team then applied those figures to actual cancer data from 2014 to roughly calculate how many cases and deaths were attributable to those lifestyle factors.

The risk factors included in the analysis were:

cigarette smoking

secondhand smoke

excess body weight

alcohol intake

consumption of red and processed meat

low consumption of fruits and vegetables

dietary fiber and dietary calcium

physical inactivity

ultraviolet light

six cancer-associated infections, including herpes and HPV

They found that an estimated 42 percent of all cancer cases in America (659,640 of the 1,570,975 cancers diagnosed in 2014) were attributable to these modifiable risk factors.

These factors were also the underlying cause of 45.1 percent of cancer deaths (265,150 of 587,521 deaths) that same year.

Staggeringly, they believe this is an understatement, since there are other risk factors that they couldn't get the data for. There are also a number of cancers which are widely suspected to be caused by certain risk factors, but the links are not yet proven.

Based on the data Dr Islami could compile, cigarette smoking accounted for the highest proportion of cancer cases and deaths: 19 percent of cases (298,970 people) and 28 percent of deaths (169,180 people).

Excess body weight was the second-riskiest, linked to 7.8 percent of cases and 6.5 percent of deaths, followed by alcohol intake (5.6 percent of cases and four percent of deaths), UV radiation (4.7 percent of cases and 1.5 percent of deaths) and physical inactivity (2.9 percent of cases and 2.2 percent of deaths).

Low fruit and vegetable intake accounted for 1.9 percent of cases and 2.7 percent of deaths, while HPV infection accounted for 1.8 percent of cases and 1.1 percent of deaths.

For women, excess body weight was far riskier than for men, since this risk factor is associated with 60 percent of uterine cancer, as well as 11 percent of breast cancers, which either exclusively or disproportionately affect women.

Physical inactivity is also riskier for women because it is more closely associated with uterine cancer than any other cancer types. By Dr Islami's estimates, lack of exercise drives 26.7 percent of uterine cancers, as well as 16.3 percent of colorectal cancers, and 3.9 percent of female breast cancers.

Smoking, meanwhile, was a higher risk factor for men, causing a third of male cancers, compared to one-fourth of female cancers.

Overall, cigarette smoking drives more than a quarter of cancers, while excess body weight and alcohol consumption are the next riskiest lifestyle factors, which could be avoided

Alcohol intake was associated with almost half of oral cancers in men (46.3 percent) and more than one-fourth (27.4 percent) in women. It also drives 24.8 percent of liver cancers in men, compared to 11.9 percent in women, and 17.1 percent of colorectal cancers in men, compared to 8.1 percent in women.

UV radiation was associated with 96 percent of melanomas of the skin in men and 93.7 percent in women.

'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,' write the authors.

'Increasing access to preventive health care and awareness about preventive measures should be part of any comprehensive strategy for broad and equitable implementation of known interventions to accelerate progress against cancer.'

Studies have shown that following the American Cancer Society's cancer prevention guidelines for maintaining a healthy body weight, limiting alcohol intake (for those who drink), consuming a healthy diet, and being physically active is associated with a reduced risk of developing and dying from cancer.

'In 1981, Doll and Peto published what has become a classic paper on the causes of cancer,' said Dr Otis W. Brawley, MD, American Cancer Society chief medical officer and study co-author.

'Since then, 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.'