MORE: John McCain's son says senator 'sounds better than the day before'
Meghan McCain is a TV commentator who co-hosts ABC's "The View."
"As everyone knows, especially with this cancer, you have to take it scan by scan, but he is doing really good, much better than I think people anticipated," she said in the radio interview.
"He's doing very well, and I feel very lucky that he is doing so well," she added.
In a previous interview, Meghan McCain said concerns about this year's brutal flu season were helping to keep her father in Arizona.
With his immune system weakened, "everybody is worried about him getting the flu," she said on a "Politico" podcast in February.
Meghan McCain and her mother, Cindy McCain, last week helped shoot down a dubious online report anticipating McCain's resignation for health reasons.
Cindy McCain tweeted that her husband "is doing fine and has no intention of resigning!"
Meghan McCain likewise definitively dubbed the report, which had gotten some traction on social media, "FAKE NEWS."
While not giving interviews to the media, the senator has continued to issue written statements from Arizona and remains active on Twitter.
On Tuesday, he raised concerns about the role Gina Haspel, President Donald Trump's new nominee for CIA director, played in the "disgraceful" torture of detainees in U.S. custody after the Sept. 11, 2001, terrorist attacks.