Almost 170,000 of those deaths are attributable to smoking alone, and another 190,000 will be related to poor nutrition, sedentary lifestyles, and obesity. Screenings would also prevent many cancer deaths, particularly from breast cancer.
More than 60 percent of all cancer deaths could be prevented if Americans stopped smoking, exercised more, ate healthier food and underwent recommended cancer screenings, the American Cancer Society reported on Thursday.
Americans could realistically cut the death rate in half, the report says.
"The American Cancer Society estimates that in 2005, more than 168,140 cancer deaths will be caused by tobacco use alone," the organization said in a statement.
"The issue is how many could you actually pull off in reality and half doesn't seem like a big stretch," Dr. Michael Thun, head of epidemiology for the non-profit group, said in an interview.
"Increasing colorectal screening and high quality mammography and Pap (tests for cervical cancer) would contribute another fraction.
For instance, breast cancer, which kills 40,000 women and men in the United States every year, can usually be easily treated if caught before it spreads.
In February a team at Harvard Medical School calculated that if every woman aged between 50 and 79 got a mammogram every year, it would reduce deaths from breast cancer by 37 percent.
Colon cancer and prostate cancer, two other top cancer killers, are also easily detected early with proper screening.
Encouraging smokers to quit and changing social norms about smoking have also helped drive the nation's smoking rate below 25 percent, he said.
Tackling obesity will be more difficult, Thun said.
"Just from a common-sense point of view, anything which increases physical activity, makes healthy food more available, limits access (to) and marketing of unhealthy foods is likely to be a step in the right direction," Thun said.
The reality is things like smoking and obesity and physical inactivity are often described as voluntary but the choices we make are made in a social context," he said.