U.S. Rep. John Lewis stands in front of John Lewis Freedom Parkway moments after its new name was unveiled in Atlanta, Wednesday, Aug. 22, 2018. Atlanta is honoring Lewis by renaming a street after the civil rights icon. (AP Photos/Brinley Hineman)

ATLANTA (AP) — Congressman John Lewis of Georgia announced Sunday that he has advanced pancreatic cancer, vowing he will keep serving and fight the disease with the tenacity with which he battled racial discrimination and other inequalities dating to the civil rights era.

Lewis, the youngest and last survivor of the Big Six civil rights activists in a group once led by the Rev. Martin Luther King Jr., said in a statement that the cancer was detected earlier this month during a routine medical visit.

The 79-year-old Democrat said subsequent tests confirmed the diagnosis of advanced pancreatic 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 added.

Lewis said he was “clear-eyed about the prognosis” even as doctors have told him that recent medical advances have made this type of cancer treatable in many cases. He added that “treatment options are no longer as debilitating as they once were.”″

Said Lewis, “I have a fighting chance.″

The American Cancer Society estimates 3% of patients with stage 4 pancreatic cancer are alive five years after being diagnosed.

Lewis added that he has decided he will return to the nation’s capital in coming days to continue work in Congress while he begins his treatment plan. He said he will undergo treatment over the next several weeks but didn’t elaborate on the specifics of what it would entail or where it would take place.

“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 in asking for prayers.

An Atlanta Democrat sometimes called the “conscience of the Congress,” Lewis is known for the prominent role he held during the 1960s civil rights struggles.

In that era, he led hundreds of protesters in the 1965 Bloody Sunday march across the Edmund Pettus Bridge in Selma, Alabama. Then 25, Lewis was at the head of the marchers when he was knocked to the ground and beaten by police. His skull was fractured, and nationally televised images of the brutality forced the country’s attention on racial oppression in the South. Lewis also joined King and four other civil rights leaders in organizing the 1963 March on Washington. There he spoke to the vast crowd just before King delivered his famed I Have a Dream speech.

Lewis turned to politics in 1981, when he was elected to the Atlanta City Council. He first won a seat in Congress in 1986 and has served since.