WASHINGTON — Presidential spokesman Tony Snow’s cancer has returned and spread to his liver and elsewhere in his body, shaken White House colleagues announced yesterday. They said he told them he planned to fight the disease and return to work.

“He is not going to let this whip him, and he’s upbeat,” President Bush said of his press secretary. “And so my message to Tony is, ‘Stay strong; a lot of people love you and care for you and will pray for you.'”

Mr. Snow, 51, had his colon removed in 2005 and underwent six months of chemotherapy after being diagnosed with colon cancer. He underwent surgery on Monday to remove a growth in his abdominal area, near the site of the original cancer.

Doctors determined the growth was cancerous and that the cancer had metastasized, or spread, to the liver. The cancer has attached to the liver but is not in the liver, White House deputy press secretary Dana Perino said.

The news rocked the White House. Mr. Snow had gone into the surgery saying he felt fine, and recent blood tests and imaging scans had indicated no return of cancer. He had said he opted to remove the growth out of “aggressive sense of caution.”

A former radio and TV commentator, Mr. Snow brought his star power to a beleaguered White House last May. He had recently reached the two-year mark of being free of cancer.