The World Health Organization is sounding the alarm about cancer.  

Its new World Cancer Report warns cancer cases globally could surge nearly 60 percent in the next two decades because of growing and aging populations.  

New cancer cases are expected to skyrocket globally from an estimated 14 million in 2012 to 22 million new cases a year within the next two decades, the report says. During that same period, cancer deaths are predicted to rise from an estimated 8.2 million annually to 13 million a year.

The agency calls the scenario a "human disaster" that can only be fought with an intense focus on prevention.

The report, which coincides with today's World Cancer Day, notes even wealthier countries will struggle to deal with spiraling cancer treatment costs, which for 2010 were estimated at more than $1.1 trillion.

Since about half of all cancers are preventable, the report says it's critical to tackle the disease by focusing on things like smoking, alcohol consumption, diet, exercise and screening programs.

Cutting smoking rates could have a major impact since lung cancer remains the most commonly diagnosed cancer worldwide and also the deadliest.

The most commonly diagnosed cancers in 2012 were lung, breast and large bowel. The deadliest cancers in 2012 were lung, liver and stomach cancer. 

According to the report, tobacco accounts for 33 percent of all cancers in the U.S. And bad diet, obesity and physical inactivity account for 28 percent."

Half of all cancers in the world could be prevented if current knowledge on the disease and what causes cancer were put into practice, the report stated. 

This would include preventing the spread of tobacco use and reducing its use, tackling obesity, promoting physical activity, adopting screening programs and encouraging vaccines to reduce risk of certain cancers such as the liver and cervix.

-- Metro Networks contributed to this report.