From here:

Presidential spokesman Tony Snow's surgery to remove a small growth showed that his cancer has returned, the White House said Tuesday.

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 metastized, or spread, to his liver, White House spokeswoman Dana Perino said.