Dan Mitchinson: US correspondent on Biden's cancer diagnosis raising questions about his health in office - Heather du Plessis-Allan Drive

Joe Biden's earlier announcement that he had been diagnosed with prostate cancer has revived questions about what health issues the former US president was facing while in office.

President Donald Trump recently claimed he was 'surprised' the public wasn't notified a long time ago - and this doctor also earlier said Biden was cognitively fine.

US correspondent Dan Mitchinson says people are curious about why more wasn't revealed sooner.

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