The cost of treating cancer has doubled over the past 20 years, but those costs are in line with overall trends in health spending. And while more people are getting cancer as the U.S. population ages, treatment has shifted away from hospitals to outpatient settings, according to a study. As cancer treatment has moved out of hospitals and into clinics or doctors' offices, the share of cancer costs for inpatient care fell from 64.4% of total cancer costs in 1987 to 27.5% a year during 2001-2005, the study found.