Hodgkin's disease

After a routine chest and abdomen scan and a follow-up biopsy of a suspicious lymph node, doctors have determined that U.S. Sen. Arlen Specter's Hodgkin's disease has returned, albeit at a "significantly less advanced" stage, according to a statement released Tuesday evening by the office of Pennsylvania's senior senator.

"It is expected that Senator Specter will continue to perform all the duties of his office as well as his activities associated with his candidacy for re-election," according to the statement.

Specter was originally diagnosed with the disease in 2005 and continued to work while undergoing treatment.