WASHINGTON -- The White House said Tuesday that presidential spokesman Tony Snow's surgery to remove a small growth showed that his cancer has returned.

Snow, 51, had his colon removed in 2005 and underwent six months of chemotherapy after being diagnosed with colon cancer. A small growth was discovered last year in his lower right pelvic area, and it was removed on Monday. Doctors determined that it was cancerous, and that his cancer had metastasized, or spread, to his liver, White House spokeswoman Dana Perino said.

She said Snow is resting comfortably after his surgery and has pledged to aggressively fight the disease with an as-yet-to-be-determined treatment course.

"He said he's going to beat it again," Perino said in an emotional morning briefing with White House reporters. "When I talked to him, he was in very good spirits."

In her afternoon briefing, Perino said that everyone at the White House was saddened by the news.

"The outpouring of support has been amazing," she said. "If you know Tony, you know he's a fighter. We gain a lot of strength from his optimism."

Snow said at a March 23 press briefing that there was a growth found during a routine test and that "Out of an aggressive sense of caution," he would be having surgery.

Speaking to reporters in the White House Rose Garden, President George W. Bush said he spoke with Snow Tuesday morning.

"His attitude is one that he won't let this whip him," Bush said. "My attitude is that we need to pray for him and his family."

"My message to Tony is 'Stay strong. A lot of people here love you and care for you and will pray for you."

Edwards Family Struck By Cancer

News of Snow's cancer comes less than a week after Elizabeth Edwards, the wife of presidential candidate John Edwards, learned that her breast cancer had spread to other parts of her body.

She was originally diagnosed with breast cancer at the end of her husband's campaign for vice president in 2004. She was treated and was thought to have been cured.

The couple met with reporters March 22 to announce that her cancer had returned, but that John Edwards' campaign for the Democratic nomination would continue.

At his press briefing that afternoon, Snow praised Elizabeth Edwards.

"Elizabeth Edwards is setting a powerful example for a lot of people, and a good and positive one," he said. "She has been on top of diagnosis and follow-up. When you have cancer it's very important to keep checking. She's being aggressive. She's living an active life."

"And a positive attitude, prayers, and people you love are always a very good addition to any kind of medicine you have," he said. "So for Elizabeth Edwards, good going; our prayers are with you.

On March 26, she said doctors had found a "hot spot" in her right hip in addition to the cancer found in one of her ribs, but said doctors told her they believe it is too small to pose a new health risk.