Arizona Sen. John McCain was expected to return to the Senate next week after an initial round of treatment for an aggressive form of brain cancer, a new report said Wednesday.

Republican aides told Politico the Republican — who celebrated his 81st birthday with family on Tuesday — plans to be back in DC next week after undergoing his first round of chemotherapy.

McCain, who chairs the Senate Armed Services Committee, will lead the debate on the National Defense Authorization Act, Politico reported.

McCain was diagnosed earlier this year with a glioblastoma, one of the most aggressive types of brain tumors.

The outspoken McCain — who voted against President Trump’s effort to repeal Obamacare, dooming the attempt to keep a major campaign promise — has not been afraid of criticizing the GOP president.

He chastised Trump over his pardon of immigration hardliner Joe Arpaio, saying that Trump’s pardon “undermines his claim for respect of rule of law as Mr. Arpaio has shown no remorse for his actions.”

He also said it was a “step in the wrong direction to force currently serving transgender individuals to leave the military,” as Trump had ordered.