Two new cancer atlases predict that a billion people could die from the disease worldwide in the 21st century. But reductions in tobacco use, better diets and controlling infections could change that dire outlook.

There are approximately 1.25 billion cigarette smokers worldwide. According to current estimates, tobacco causes one in five, or 1.4 million, cancer deaths globally each year.

The annual toll increases to almost 5 million when deaths from tobacco-related cardiovascular and pulmonary diseases are included, and it's likely to continue rising.

Smoking, Diet Major Cancer Culprits

Of the 10.9 new cancer cases reported in 2002, 1.35 million were lung cancer, 1.15 million were breast cancer, 1 million were colon cancer, 930,000 cases were stomach cancer, and 679,000 were prostate cancer.

There were 6.7 million deaths attributed to cancer in 2002.

A reduction in tobacco use would have a greater impact on global cancer rates than any other factor, experts say.

Healthier diets -- that is, less consumption of saturated fats and greater emphasis on fresh fruits and vegetables -- would also be beneficial. In addition, people should avoid alcohol and salty foods, and maintain a healthy weight, the reports advised.

Bleak Forecast

Curbing infections caused by cancer-causing viruses and bacteria also could cut cancer rates dramatically. Helicobacter pylori causes 5.6 percent of all cancers, which increases the risk of stomach cancer between five- and sixfold, according to the atlases.

Cervical cancers are caused by the human papillomavirus, while hepatitis B and C can cause liver cancer.

"We know with cancer, if we take action now, we can save 2 million lives a year by 2020 and 6.5 million by 2040," commented Dr. Judith Mackay, a senior policy adviser at the World Health Organization.

However, expected population increases mean that even with a global decrease in smoking rates, the actual number of smokers -- and victims of related diseases -- could still rise.