The archbishop of Chicago made a public appearance to talk about the canonizations later this month of Popes John XXIII and John Paul II and his declining health.
Cardinal Francis George met with reporters Friday.
The archdiocese announced earlier this week that George canceled plans to travel to Rome for the April 27 canonizations because of the resumption of his chemotherapy.
Treatment of the cancer near his right kidney had been interrupted when he hospitalized recently for dehydration and flu-like symptoms.
He'd hoped to travel to the Vatican , but says: "I don't want to do something dangerous."
The Roman Catholic Church has told him it will begin searching for his successor because of his "uncertain" health as he undergoes chemotherapy.
He says the lengthy, formal process has not begun, but will start soon.
For now, he says he is relying on the prayers of the Catholic people to help him through the illness.
George says although it is difficult to go through cancer treatments, he has found that the courage that is needed when facing battles is a silver lining. He says he has received several letters of encouragement from cancer survivors.
The archdiocese says George still intends to participate in the Holy Week services and Easter Sunday Mass at Holy Name Cathedral.
The 77-year-old is the spiritual leader of Chicago's more than 2 million Roman Catholics.
Copyright 2014 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.