Lauren Loftus/KJZZ

John McCain in KJZZ's studio in 2016.

Family members of Arizona Sen. John McCain say he has completed the first round of radiation and chemotherapy as he battles an aggressive form of brain cancer.

Meghan McCain, the daughter of Arizona’s senior senator tweeted Friday afternoon that her father's "resilience & strength is incredible. Fight goes on, here's to small wins."

McCain, the Republican presidential nominee in 2008 and a six-term senator, was diagnosed last month with glioblastoma. Doctors at the Mayo Clinic in Phoenix removed a blood clot above hist left eye and managed to remove all of the tumor that was visible on brain scans.

McCain said s he expects to return to Washington, D.C., next month.