Story highlights Monthly spending on certain cancer patients in Washington was $12,345 vs. $6,195 in British Columbia

Despite paying double, Americans died slightly faster than Canadians in the study

(CNN) Americans paid twice as much as Canadians for health care, but they didn't get twice the benefit, according to a new study of patients with advanced colorectal cancer who lived, in some cases, mere miles from each other.

The patients had similar diagnoses, levels of education, financial situations and other demographics that commonly affect health outcomes and mortality. Some of their ages were different, but the biggest difference between them is on which side of the border they live.

Using data from hospitals, Dr. Todd Yezefski of Fred Hutchinson Cancer Research Center in Washington found that a total of about $12,345 was spent a month on the cancer patients in his study who lived in western Washington, whereas the monthly spending for British Columbia patients was $6,195.

Care varied slightly for the two groups. American doctors ordered chemotherapy more often than the Canadian doctors did, but that may have been because the US patients were a little younger as a group than the Canadian patients, Yezefski said. But most everything else was the same, and while American patients' treatment was twice as expensive, these patients didn't live any longer than the Canadians.