单选题第三篇 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 Intemational 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 1 0 million new cancers were diagnosed globally in 2000。and that number is expected to rise to 1 5 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)countries，”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．”