Former United States President Joe Biden was not diagnosed with prostate cancer before last week, and received his ?last known? blood test for the disease more than a decade ago, his office has said.

The Biden camp?s statement on Tuesday came as critics, including current President Donald Trump, stoked scepticism over the timing of the diagnosis, which has reanimated questions about whether the former president misled the public about his health while in office.

?President Biden?s last known PSA was in 2014,? Biden?s office said in the brief statement, referring to the prostate-specific antigen test used to detect prostate cancer.

?Prior to Friday, President Biden had never been diagnosed with prostate cancer.?

On Monday, Trump said he was ?surprised? that the public had not been notified about Biden?s diagnosis ?a long time ago?.

?Why did it take so long? This takes a long time. It can take years to get this level of danger,? Trump told reporters at the White House, referring to the advanced nature of Biden?s cancer.

?Somebody is not telling the facts, and that?s a big problem,? Trump said.

Biden?s office said on Sunday that the former president had, two days earlier, been diagnosed with prostate cancer that had spread to his bones.

Biden?s office said his cancer had score of 9 under the Gleason classification system, which grades prostate cancer from 6 to 10, indicating it is among the most aggressive kinds.

While some doctors have expressed doubt that Biden, 82, was not diagnosed earlier given his access to the best medical care, others have noted that screening is generally not recommended for men of his age and that some cancers do not show up in tests.

The US Centers for Disease Control and Prevention and other medical bodies do not recommend regular screening for prostate cancer for men over 70 due to the quality of life issues that can result from unnecessary treatment.

?It is entirely reasonable, albeit sad, that even a person of President Biden?s position may present with a new diagnosis of prostate cancer that is metastatic at his age,? Adam Weiner, an urologic surgeon at Cedars-Sinai Medical Center in Los Angeles, told Al Jazeera.

?Since President Biden is now 82, it is entirely possible he was screened for prostate cancer up to the recommended age and his newly diagnosed prostate cancer first occurred sometime since then,? Weiner said.

Nick James, an expert in prostate cancer at The Institute of Cancer Research in London, said the Biden camp?s account of the diagnosis was ?plausible even if a bit unusual?, as certain cancers with a low PSA production can be missed in blood tests.

?It?s one of the drawbacks of PSA testing is that it can miss such tumours. Likewise, prostate MRI, the other test he might have had, also has a false negative rate,? James told Al Jazeera.

Biden?s age and health were major concerns for voters during his presidency and re-election campaign, which the former president abandoned following a disastrous debate performance against Trump in June.

Critics have accused Biden and his team of covering up the extent of his mental and physical decline while in office.

On Tuesday, CNN anchor Jake Tapper and Axios correspondent Alex Thompson released a new book, Original Sin, detailing the Biden camp?s alleged efforts to conceal his deterioration.

The book includes numerous accounts of Biden?s alleged decline, including an incident in which the then-president was said to have not been able to recognise Hollywood actor George Clooney at a 2024 fundraiser. (Al Jazeera)

Update news