Tom Coburn, Okla. senator, to step down at end of 113th Congress Sen. Tom Coburn, R-Okla., plans to give up his Senate seat at the end of this Congress, he said in a statement Thursday night. "Serving as Oklahoma's senator has been, and continues to be, one of the great privileges and blessings of my life," said Coburn, 65. But after much prayer and consideration, I have decided that I will leave my Senate seat at the end of this Congress. Coburn, a licensed physician who formerly specialized in family medicine, obstetrics and allergy treatment, has been battling prostate cancer, and has previously suffered from colon cancer and melanoma. But he said he was stepping down to honor his pledge to serve no more than two terms in the Senate, though he will be stepping down two years before his term expires. He was first elected to the House in 1994, where he served three terms, and later was elected to the Senate in 2004. "As a citizen, I am now convinced that I can best serve my own children and grandchildren by shifting my focus elsewhere," Coburn said in his statement. In the meantime, I look forward to finishing this year strong. I intend to continue our fight for Oklahoma, and will do everything in my power to force the Senate to re-embrace its heritage of debate, deliberation and consensus as we face our many challenges ahead. Known as a conservative maverick during his three terms in the U.S. House in the 1990s, Coburn continued that role after being elected to the Senate in 2004. He was a fierce critic of what he described as excessive government spending, and was most vocal about opposing the earmarking of special projects. Senate Republican Leader Mitch McConnell reacted to the news by describing Coburn as "one of the most intelligent, principled, and decent men in modern Senate history" in a statement. Tom is a legend in his own time, an extraordinary man and a deeply serious lawmaker who has made an immense difference to his country and to this body. We will miss him terribly when he leaves the Senate, and we will stand with him every step of the way as he wages this latest of many tough battles that he has fought, and won," the statement read.