FACTBOX: Medicare's top 5 most costly cancers

(Reuters) - Treating elderly cancer patients in the United States cost Medicare $21.1 billion from 1999-2003, according to the National Cancer Institute.

Following is the five-year bill for treating the five most costly cancers among elderly Medicare patients. The figures are based on a 2004 diagnosis and cost estimates are in 2004 dollars.

* Lung cancer -- $4.2 billion

* Colorectal cancer -- $3.1 billion

* Prostate cancer -- $2.3 billion

* Female breast cancer -- $1.4 billion

* Lymphoma -- $1.4 billion

Source: Journal of the National Cancer Institute

(Reporting by Julie Steenhuysen in Chicago, Editing by Maggie Fox)