In the United States, the average life span of cancer patients, that is the life span from being diagnosed with cancer to death is 7 years, while the average life span of cancer patients in Asia is only 4 years. 
Among the various cancers, the incidence of lung cancer, which has the shortest survival time, is higher in the United States than in Asia
 the United States has a higher level of medical care in extending the lifespan of cancer patients than Asia.