单选题：Global Cancer Rates to Rise by 50% by 2020　　The number of ne

Global Cancer Rates to Rise by 50% by 2020　　The number of new cancer cases worldwide is expected to increase by 50% by the　year 2020. But a new report suggests that as many as a third of new cancers could be　avoided by adopting healthier lifestyles and through public health action.
　　The World Cancer Report, released by the International Agency for Research on　Cancer, shows that cancer has now emerged as a major public health threat in　developing countries as well as rich ones.
　　Overall, cancer was responsible for 12% of all deaths in 2000. But in many
countries more than a quarter of all deaths are caused by cancer.
　　The report shows that 10 million new cancers were diagnosed globally in 2000, and　that number is expected to rise to 15 million by 2020. Researchers say most of that　increase will mainly be due to steadily aging populations in both developed and　developing countries and current trends in smoking and other unhealthy habits.
　　"Cancer has emerged as a major public health problem in developing countries for　the first time, matching its effect in industrialized (工业化的) ountries," said researcher　Paul Kleihues, MD, director of IARC, in a news release. "Once considered a 'Western'　disease, the Report highlights that more than 50 percent of the world's cancer burden, in　terms of both numbers of cases and deaths, already occurs in developing countries."
　　The risk of being diagnosed with cancer in developed countries is double that in　less-developed ones. However, the risk of dying from cancer is much higher in　developing countries, where 80% of cancer patients already have late-stage incurable　tumors (肿瘤) at the time of diagnosis.
　　Researchers say cancer rates have traditionally been higher in developed countries　due to greater exposure to tobacco, occupational carcinogens (致癌物); and an　unhealthy Western diet and lifestyle. As less-developed countries become industrialized　and more prosperous, they tend to adopt the high-fat diet and low physical activity levels　typically seen in the West which increase cancer rates.The report says that steps could be taken to reduce about A．50% of new cancer
B．33% of new cancer
C．12% of new cancer
D．80% of new cancer