Cardinal Francis George of Chicago has been in the hospital at Loyola University Medical Center since Friday, after physicians found during a routine checkup that he was dehydrated.

"Cardinal George is expected to be released from the hospital later this week," the Chicago archdiocese said March 18.

"He asks that people continue to pray for him as he continues to keep people in his prayers."

He is being treated with an antibiotic, and is receiving intravenous fluids; he is expected to be released from the hospital later in the week.

Earlier in the month, he announced to his local Church that a cancer in his right kidney which had been dormant for more than a year, is "showing signs of new activity."

"While I am not experiencing symptoms of cancer at this time, this is a difficult form of the disease, and it will most probably eventually be the cause of my death," he wrote in his most recent column for the Catholic New World archdiocesan paper.

He was advised to enter into an aggressive round of chemotherapy which will take place over the next two months.

The 77-year-old cardinal underwent a medical procedure August 2012 that discovered cancerous cells in his kidney and in a nodule that was removed from his liver.

In his column, Cardinal George also said "I imagine this news will increase speculation about my retirement." However, the "only certainty is that no one knows when that will be, except perhaps the Holy Father, and he hasn't told me."

"In the meantime, Lent gives me a chance to evaluate not only my life of union with the Lord but also my life and actions here as Archbishop of Chicago."

Cardinal George was born in Chicago in 1937, and in 1963 was ordained a priest of the Oblates of Mary Immaculate.

He was consecrated a bishop in 1990, serving as bishop of Yakima, and Portland in Oregon, before his 1997 appointment to the Archdiocese of Chicago.