CNN conditions expert Dr. Otis Brawley is the chief medical officer of the American Cancer Society, a world-renowned cancer expert and a practicing oncologist. He is also the author of the book " How We Do Harm: A Doctor Breaks Ranks About Being Sick in America ."

(CNN) The World Health Organization is sounding the alarm: cancer is rapidly becoming a global pandemic.

In its World Cancer report, the U.N. agency notes the disease causes one in eight deaths worldwide. It's estimated 14 million were diagnosed with cancer in 2012 and 22 million will be diagnosed by 2032.

The most commonly diagnosed cancers worldwide are cancers of the lung, breast and colon. The most common causes of cancer deaths worldwide are lung, liver and stomach cancer. In certain areas of Africa and Asia, cervical cancer is the leading cause of death in women.

What's behind the increase? Aging and growth of the world population, as well as the spread of cancer risk factors into low- and middle-income nations.

Otis Brawley

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Those include use of tobacco, obesity, lack of physical activity and poor diet. The report refers to those as "an industrialized lifestyle;" they cause about half the cancer deaths in the United States and Western Europe.

At the same time, cancer death rates have declined by about 20% over the past 20 years in the United States and Western Europe. This is largely because of prevention activities, especially a decrease in smoking.

Tobacco use in low- and middle-income countries is causing cancer death rates to increase. Other cancer-causing habits common in the West, such as nutritionally poor and high-calorie diets that promote obesity, are increasing in low- and middle-income countries as well.

These countries also have inadequate medical and public health infrastructures. In economically developing countries, cancers are often diagnosed at a late stage when eliminating the disease is no longer possible.

People often suffer because palliative care is inadequate. Narcotics are not available for palliative care in more than two dozen countries and are difficult to get in many others.

The report emphasizes that governmental and nongovernmental international organizations need to be serious about cancer prevention activities in low- and middle-income countries. The report also illustrates that prevention efforts need to be re-emphasized in developed countries such as the United States.

But cancer doesn't have to be inevitable. There is plenty you can do to lower your risk.

Don't use tobacco products

If you smoke, stop. It is never too late to quit. There are health benefits within 24 hours of the last cigarette.

Stay trim without being underweight

Avoid excess weight gain at all ages. For those who are overweight or obese, losing even a small amount of weight has health benefits and is a good place to start.

Limit intake of high-calorie foods and drinks as keys to help maintain a healthy weight. Keep a healthy diet, with an emphasis on plant foods.

Choose foods and drinks in amounts that help you get to and maintain a healthy weight. Limit how much processed meat and red meat you eat. Eat at least 2.5 cups of vegetables and fruits each day. Choose whole grains instead of refined grain products.

If you drink alcohol, limit your intake -- no more than one drink a day for women or two for men.

Get regular physical activity

Adults: Get at least 150 minutes of moderate intensity or 75 minutes of vigorous intensity activity each week (or a combination of these), preferably spread throughout the week.

Children and teens: Get at least one hour of moderate or vigorous intensity activity each day, with vigorous activity on at least three days each week.

Limit sedentary behavior such as sitting, lying down, watching TV and other forms of screen-based entertainment. Doing some physical activity above usual activities, no matter what one's level of activity, can have many health benefits.

Get vaccinated

Several of the leading causes of cancer are caused by infections that can be controlled through vaccination. The hepatitis B vaccine is now a standard vaccine for children in the United States and Europe; adults who have not been vaccinated should consider it.

The human papillomavirus vaccine is commonly given to girls and prevents infection with the virus that causes most cervical cancers. There is increasing evidence it might prevent some head and neck cancers, and some experts recommend boys be vaccinated as well.

Avoid unnecessary sun exposure

Wear long-sleeved shirts, long pants and wide-brimmed hats when possible. Use sunblock when sun exposure is absolutely necessary. This will reduce your risk of melanoma and other skin cancers.

Those with the opportunity, living in areas where it's available, should participate in screening for certain cancers. Screening for cervical, breast and colon cancer can save lives.