(CNN) - Former U.S. Sen. Arlen Specter of Pennsylvania left a hospital in Philadelphia Friday after receiving treatment for non-Hodgkins lymphoma, according to a statement released through his attorney.
The statement also said Specter would return to the University of Pennsylvania Hospital to receive periodic treatments for the disease, a type of blood cancer.
Last week Specter revealed in a statement he was battling non-Hodgkins lymphoma after overcoming numerous serious illnesses over the past two decades, including a brain tumor.
"I'm battling cancer. It's another battle I intend to win," Specter said the statement, released last Tuesday. "I'm grateful for all the well wishes I've received. I'm looking forward to getting back to work, to the comedy stage, to the squash court and to the ballpark."
Specter, 82, served in U.S. Senate from 1980 until 2011, making him the longest-serving senator from Pennsylvania.
Nearly all of those years, the political moderate was a member of the GOP, but he switched parties and became a Democrat in 2009, saying Republicans had moved too far to the right.
The move gave Democrats a 60-seat filibuster-proof majority in the Senate.
Two years later, when he ran for re-election, Specter lost in the Democratic primary, ending his political career.
After the loss, he moved from the halls of Congress to those of academia, taking on a new role at the University of Pennsylvania Law School.
Specter also returned to his law practice after leaving the Senate, according to his official online biography.
Specter was born in Wichita, Kansas, in 1930. He is the youngest child of Lillie Shanin and Harry Specter, an immigrant from the Ukraine.