Carson has been on leave from Congress since late summer for treatment of a leg infection. During the treatment, her doctor discovered the cancer, Carson, 69, said in a statement Saturday.

"It had gone into remission years before, but it was back with a terminal vengeance," said Carson.

Known as a advocate for the poor and the marginalized, Carson opposed going to war in Iraq and, in 1999, won enactment of a measure giving the Congressional Gold Medal to civil rights legend Rosa Parks.

State Sen. Glenn Howard, D-Indianapolis, called Carson a beautiful person who has helped many and now can depend on her friends to do whatever she needs during her illness, the Star said.

Carson has not made public any future plans regarding her office.