Cancer death rates have declined steadily in the U.S., where people now have a 20 per cent lower overall risk of dying compared with 20 years ago, according to a new report. 

Tuesday's estimates from the American Cancer Society suggest there will be 1,665,540 new cancer cases and 585,720 deaths from cancer in the U.S. in 2014.

Among men, prostate, lung and colon cancer will account for about half of all newly diagnosed cancers.

Lung Cancer Screening

Just over one in four cancer deaths is due to lung cancer in the U.S. (Jim Cole/Associated Press)

Among women, the three most common cancers in 2014 will be breast, lung, and colon, which together will account for half of all cases, the society said.

Just over one in four cancer deaths is due to lung cancer in the U.S.

Since women began smoking in large numbers about 20 years later than men, the decline in lung cancer incidence rates among women in the U.S. began in the late 1990s compared with the mid-1980s for men, the group said.

"The biggest reason for this 20 per cent decline we're celebrating is prevention, it's actually smoking cessation and people not smoking in the 1960s and '70s," Dr. Otis Brawley, chief medical officer for the American Cancer Society, said in an interview. 

Brawley said two-thirds of cancers are linked to the combination of bad diet, lack of physical activity, obesity and smoking.

"I think we need to double down our efforts in prevention," he said.

Last year, the Canadian Institute for Health Information said at 58 deaths per 100,000 population, lung cancer mortality in Canada is higher than the OECD average of 43 per 100,000.

In the U.S., cancer deaths have declined by about half among middle-aged black men. Despite the progress, black men continue to have the highest cancer incidence and death rates among all ethnicities in the U.S. Asian Americans have the lowest rates.

After smoking, Brawley said the number 2 reason driving cancer death rates is that more people are living into their 70s and 80s.

While cancer survival has improved, detection and treatment of heart disease has improved even more, said Dr. Ben Neel, director of research for the Princess Margaret Cancer Centre in Toronto.

Researchers are making progress in better understanding cancer, which is starting to pay off in new therapies, Neil said. He's optimistic that cancer survival rates will continue to show major improvements in the next 20 to 30 years.

Overall in 2013, the Canadian Cancer Society estimated, 187,600 people learned they had a new cancer (excluding non-melanoma skin cancers). About 75,500 Canadians will die from some form of malignancy each year.

With files from CBC's Kas Roussy and Amina Zafar