Sen. Tom Coburn (R-Okla.) underwent surgery Monday to treat an early form of prostate cancer, his office confirmed today.

“Dr. Coburn underwent a procedure this week to treat an early stage incidence of prostate cancer. He is expected to make a full recovery and return to his full-time duties later this month,” Coburn spokesman John Hart said in a statement.

The Oklahoma Republican, who is a medical doctor, is currently serving his second term in the Senate and has pledged not to run for re-election in 2016.

The Oklahoman first reported the news of Coburn’s surgery.

Coburn is a cancer survivor dating back to the 1970s. In 1975 he was treated for melanoma, and in 2003 he was treated for colon cancer. In 2007, he had surgery to remove a benign pituitary tumor.