Senator John McCain listens as he is introduced at a campaign rally in Fayetteville, North Carolina, on October 28, 2008.

:: US Senator John McCain, the 2008 Republican presidential nominee known for political independence during more than three decades in the Senate, has been diagnosed with an aggressive form of brain cancer, his office said on Wednesday.

The 80-year-old lawmaker and former Navy pilot, who was re-elected to a sixth Senate term in November, has been recovering at home in Arizona since undergoing surgery at the Mayo Clinic in Phoenix last Friday to remove a blood clot from above his left eye. Tissue analysis since that procedure revealed that a brain tumor known as a glioblastoma was associated with the clot, his office said.

Glioblastoma is considered a grade IV tumor, the most malignant of gliomas. It can be very aggressive and spread into other parts of the brain quickly, according to the MD Anderson Cancer Center. McCain’s doctors said he was recovering from his surgery “amazingly well” and that his underlying health was excellent.

Treatment options

His treatment options include a combination of chemotherapy and radiation, his office said. “The news of my father’s illness has affected every one of us in the McCain family,” McCain’s daughter Meghan said in a statement on Twitter. “My grandmother, mother, brothers, sister, and I have all endured the shock of the news, and now we live with the anxiety about what comes next.”

She said the family was familiar with the experience of battling cancer since her father had fought it previously, and that through all of this, McCain himself was the “most confident and calm” of all of them.

His fellow members of Congress rushed to offer tributes to the lawmaker and wishes for his quick recovery. Known for an independent political streak, ready wit and strong opinions, McCain is one of the best-known and most popular US lawmakers among his peers and the media.

US President Donald Trump said that “Senator John McCain has always been a fighter,” adding: “Get well soon.” Former Democratic President Barack Obama, who defeated McCain for the presidency in 2008, called McCain “an American hero and one of the bravest fighters I’ve ever known. Cancer doesn’t know what it’s up against. Give it hell, John.”