The former senator who served as both a Democrat and Republican has previously fought cancer before. In 2005 he underwent chemotherapy to battle Hodgkins disease.
In announcing that he would receive cancer treatment again, Specter said that it was a battle he intended to win.
"I'm battling cancer. It's another battle I intend to win," Specter said the statement announcing that he would receive treatment. "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."