Rep. John Lewis will undergo treatment for stage 4 pancreatic cancer, his office said Sunday.
He learned of the diagnosis this month, after what Lewis, D-Ga., described as a "routine medical visit and subsequent tests."
"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 said in the statement.
Lewis, who represents Georgia's fifth Congressional District, said he plans to return to Washington "in coming days to continue our work and begin my treatment plan, which will occur over the next several weeks."
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Lewis, a civil rights icon who was elected to Congress in 1986, alluded to the various battles he has faced throughout his career in his announcement.
"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," he said.
The congressman received an outpouring of support online from colleagues following the announcement.
"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," former President Bill Clinton tweeted on Sunday.
"Praying for my friend and hero @repjohnlewis who has as much bravery and strength as anyone I've ever known", Delaware Sen. Chris Coons wrote on Twitter.
Rep. Veronica Escobar, D-Texas, said, "I am so deeply saddened by this news. Knowing and working with him has been one of the greatest blessings of my life in public service. But I also have faith that John Lewis will beat this. He is a warrior like no other. Sending you much love and all my prayers, @repjohnlewis."
Nearly 57,000 people in the United States will have been diagnosed with pancreatic cancer in 2019, according to the American Cancer Society's estimate. The disease, which accounts for about seven percent of all cancer deaths, according to ACS, is more common in men than women.