President Biden’s office says he hadn’t had a prostate-specific antigen test, commonly referred to as a PSA test, since 2014, prompting new questions about why the 82-year-old did not take the simple blood test that can indicate signs of cancer.

“President Biden’s last known PSA was in 2014. Prior to Friday, President Biden had never been diagnosed with prostate cancer,” his office said in a statement.

The PSA test is commonly used to screen for prostate cancer, measuring the level of prostate-specific antigen in the blood. The protein is produced by both cancerous and noncancerous tissue in the prostate, a gland situated below the bladder in males.

Some top Democratic politicos say Mr. Biden’s cancer announcement should end discussion about his mental acuity. “I think those conversations are going to happen, but they should be more muted and set aside for now, as he’s struggling through this,” an adviser to President Obama and Mr. Biden, David Axelrod, said. “This supersedes all of that, obviously.” 

The House Democratic leader, Hakeem Jeffries, dismissed theories that Mr. Biden has had cancer for far longer than had been disclosed. “It seems entirely inappropriate at this moment in time, when President Biden is dealing with a serious and aggressive form of cancer, there are Republicans peddling conspiracy theories and want us to look backward,” he said.

Prostate cancer, if caught early, is highly treatable, though it is still the second-leading cause of cancer death in men. The American Cancer Society says one in eight men are diagnosed with prostate cancer in their lifetimes.

“The PSA test can detect high levels of PSA that may indicate the presence of prostate cancer,” according to the Mayo Clinic. “However, many other conditions, such as an enlarged or inflamed prostate, also can increase PSA levels. Therefore, determining what a high PSA score means can be complicated.”

The severity of Mr. Biden’s prostate cancer has raised other concerns. His cancer has been given a Gleason score of 9 (out of 10), which signifies a high-grade form of the disease that has metastasized to the bone. The Gleason scale is used by medical professionals to classify the severity of prostate cancer. 

An oncologist who worked as a Covid adviser to the Biden White House, Ezekiel Emanuel, has noted that prostate cancer is slow-moving, but to have a Gleason score of 9 means Mr. Biden has had it for a long time.

“He’s had this for many years, maybe even a decade, growing there and spreading,” Dr. Emanuel said on MSNBC. “He did not develop it the last 100, 200 days. He had it while he was president, he probably had it at the start of his presidency,” the doctor said, adding that only about 7 percent of prostate cancer cases get diagnosed this late, after it has metastasized.

Health experts have noted that Mr. Biden’s cancer, described as hormone-sensitive, may respond well to hormone therapies, potentially making it more treatable. However, the advanced stage of the cancer has drawn scrutiny, especially given that Mr. Biden’s had regular physical exams during his time as a public figure.

“It takes a long time to get to that situation,” President Trump said on Monday, adding he was “surprised that the public wasn’t notified a long time ago.”

“There are things going on that the public wasn’t informed of. I think somebody’s going to have to speak to his doctor. This is no longer politically correct. This is dangerous for our country. Somebody is not telling the facts,” the president said.