Ed O'Keefe is CBS News' senior White House and political correspondent reporting for all CBS News platforms. He's part of the team covering President Trump and covered all four years of Joe Biden's presidency. From the White House to the campaign trail, O'Keefe's reports stretch from the politics of the moment to how policy enacted in Washington affects the nation and the world.

Former President Joe Biden has completed a round of radiation therapy to treat an aggressive form of prostate cancer -- an encouraging sign of progress -- but one that does not signal the end of his treatment.

A Biden spokeswoman confirmed to CBS News Monday that the former president, who turns 83 next month, finished several weeks of radiation therapy treatment Monday at Penn Medicine Radiation Oncology in Philadelphia. His office first announced Oct. 11 that the former president had been undergoing radiation treatment for prostate cancer for several weeks.

"He rang the bell today," Biden spokeswoman Kelly Scully said.

Ashley Biden, the daughter of the former president, posted on Instagram a quick video clip of her father ringing the bell, with the caption, "Rung the bell! Thank you to the incredible doctors, nurses, and staff at Penn Medicine. We are so grateful!"

Subsequent photos posted by the one-time first daughter show the former president posing with a medical professional, and another with former first lady Jill Biden and two of their grandchildren with the caption, "Dad has been so damn brave throughout his treatment. Grateful."

Most cancer treatment centers encourage patients to ring a wall-mounted bell when they complete cancer treatment to signal their progress and encouragement to other patients. But it is unclear at this time whether Biden will need to undergo any other treatment, since doctors always need to assess a patient's progress in the weeks after they complete cancer treatment.

Biden announced in May that he had an advanced stage of prostate cancer that has metastasized, or spread, to his bones, prompting an outpouring of concern and a new round of questions about his health and whether he faced undisclosed or unknown medical challenges during his presidency.

According to a statement from his office in May, the former president was diagnosed with "prostate cancer, characterized by a Gleason score of 9 (Grade Group 5) with metastasis to the bone" after a small nodule was found in the prostate.

Gleason scores are a grading system, and the lower the grade, the more cancer cells look like normal cells. A score of 9 is the second-highest, CBS News previously reported, and places Biden in the most aggressive risk category.

Prostate cancer is the second-most common cancer that affects men, according to the Cleveland Clinic. Age is the most common risk factor. The condition has many forms of treatment, including radiation, chemotherapy, surgery and hormone treatment.

Biden also underwent a skin cancer surgery in September 2025. That procedure was a Mohs surgery, which involves cutting away thin layers of skin until only cancer-free tissue remains in the affected area.

The former president is occasionally spotted in Washington, where he still keeps an office, and aboard Amtrak trains to and from his home in Delaware. He has begun fundraising and planning for an eventual library and museum documenting his time in the White House.

Biden completes round of radiation therapy to treat aggressive prostate cancer