Rep. John Lewis of Georgia has been diagnosed with stage 4 pancreatic cancer, his office announced Sunday.

Lewis, 79, revealed that he was diagnosed following a routine medical visit and that he will undergo treatment for the cancer.

"I have been in some kind of fight -- for freedom, equality, basic human rights -- for nearly my entire life. I have never faced a fight quite like the one I have now," Lewis, who in March 1965 joined forces with Martin Luther King Jr. to lead a voting rights march out out Selma, Alabama, said in a statement.

He continued later: "While I am clear-eyed about the prognosis, doctors have told me that recent medical advances have made this type of cancer treatable in many cases, that treatment options are no longer as debilitating as they once were, and that I have a fighting chance."

Lewis is in his 17th term as a member of Congress, and says that he will return to Washington to continue his lie's work.

"I may miss a few votes during this period, but with God's grace I will be back on the front lines soon," he said. "So I have decided to do what I know to do and do what I have always done: I am going to fight it and keep fighting for the Beloved Community. We still have many bridges to cross," Lewis said Sunday.

 House Speaker Nancy Pelosi tweeted out a message of support:

"John, know that generations of Americans have you in their thoughts & prayers as you face this fight. We are all praying that you are comfortable. We know that you will be well."

Former President Bill Clinton also tweeted a touching message to the Georgia representative, "If there's anyone with the strength and courage to fight this, it's you, John. Hillary and I love you, and we join with millions of other Americans in praying for you and your family."