CHICAGO (CNS) – Cardinal Francis E. George of Chicago will work with his doctors to determine a course of treatment after test results showed cancerous cells in his kidney and in a nodule removed from his liver.

The archdiocese made the announcement Aug. 17. The cardinal received the results after undergoing a procedure Aug. 15 at Loyola University Medical Center.

After resting at home over the weekend, Cardinal George went on retreat for a week. “We have no further information at this time,” the archdiocese said.

Prayers were said for the cardinal and all those battling cancer during all weekend Masses.

Cardinal George has headed the Chicago Archdiocese since 1997. He was made a cardinal a year later. He was president of the USCCB from 2007 to 2010.

In late July, 2006, he underwent surgery for bladder cancer. Doctors removed Cardinal George’s bladder, prostate gland and sections of his ureters – the tubes that carry urine from the kidneys to the bladder – after a biopsy showed there was cancer in his bladder and a blockage indicating that the disease was moving into one of the ureters.

After his release from the hospital, he recuperated at home and kept a limited schedule. By late fall of that year, he resumed a normal schedule.

Pathology tests after his surgery showed that the cancer hadn’t spread, and his doctors called him a “cancer survivor.”