The late-stage cancer diagnosis of former U.S. president Joe Biden has some medical professionals wondering how the disease was able to go undetected when his health had been under intense scrutiny near the end of his presidency.
In a statement on Sunday, Biden's office said the 82-year-old has been diagnosed with prostate cancer and that it's spread to the bone. He was diagnosed with Stage 4 cancer, which is considered to be the most advanced.
Prostate cancer cells are usually graded on a scale of 1 to 10 under the Gleason system.
This grading system involves looking at cells under a microscope and measuring how abnormal they are and their likelihood of spread. The higher the grade, the more aggressive the cancer.
According to Biden's office, he scored a 9, which would suggest that his cancer is among the most "aggressive."
WATCH | Biden thanks supporters after sharing cancer diagnosis:There’s been an outpouring of support for former U.S. president Joe Biden after he revealed he’s battling aggressive prostate cancer. While the disease isn’t curable, doctors say treatments may help manage it for years."It's sad, of course," Dr. Peter Black, director of the Vancouver Prostate Centre, said about Biden's diagnosis.
"It's something that we can still control for a few years, but it's definitely going to impact his quality of life and maybe his longevity."
Considering all of the debate around Biden's health during his presidency and the start of his second presidential campaign, before he pulled out of the race last summer, the diagnosis has raised questions about why this wasn't caught sooner and what it means for his long-term health..
What is prostate cancer, and what are the symptoms?The prostate, a gland in the male reproductive system that makes a fluid that is part of semen, is below the bladder. Cancer starts in the cells of the prostate and can grow into nearby tissue. The cancer can also spread to other parts of the body, including the bladder, nearby lymph nodes, bones and the brain, according to the Canadian Cancer Society.
"There's a broad spectrum of prostate cancer," said Black, who is also a urologist at Vancouver General Hospital. "From very early, relatively harmless disease, to something that's high risk and has already spread."
Dr. James Dickinson, a professor of family medicine and community health sciences at the University of Calgary, says symptoms can vary from person to person. (Submitted by James Dickinson)Symptoms can vary from person to person, said Dr. James Dickinson, a professor of family medicine and community health sciences at the University of Calgary.
But most often, he said, there are no symptoms at all. Some uncommon symptoms include trouble urinating or blood in the urine.
"It may develop and spread quite widely before anybody notices," he said.
How many people in Canada are diagnosed with it?The Canadian Cancer Society says prostate cancer is the most common cancer among Canadian men and, within that group, the third-leading cancer-related cause of death.
In 2024, the organization estimated that 27,900 men would be diagnosed with prostate cancer, with 5,000 of them expected to die from the disease.
It is most common in older men and mostly seen in Black men, including people of African and Caribbean ancestry, according to the organization.
How are people screened for it?There are two methods used to screen for prostate cancer, though research finds that each one has its downsides.
There's the prostate-specific antigen (PSA) test, which is a blood test that looks at the levels of PSA — a substance made by the prostate. As people age, PSA levels tend to increase.
Levels that are higher than normal could mean there's an issue with the prostate, but cancer isn't always the culprit. Other reasons could be an enlarged prostate or inflamed prostate gland due to an infection.
There's also a digital rectal exam (DRE), which involves a health-care provider inserting a gloved finger into the rectum and feeling for anything unusual, like lumps, the cancer society says.
But Black, of the Vancouver Prostate Centre, said while health-care providers frequently used this method in the past, they've "drifted away" from it as it's not very helpful. As a result, PSA testing is more commonly used.
When is screening recommended?Prostate cancer screening has been controversial, Black said, adding that he would recommend PSA testing for otherwise healthy men between the ages of 50 and 75.
"I'm pro-screening because I see the benefit and I see what happens if we don't screen," he said.
People older than 70 or 75 are generally not actively screened because experts say the disease is usually slow growing.
Debate over the benefits of PSA testing means that not everyone is in favour.
More than a decade ago, the Canadian Task Force on Preventive Health Care recommended against PSA screening because "the potential harms of screening outweigh the benefits."
It maintains this stance, saying that the main problems are false-positive results and overdiagnosis, the review indicated. A positive PSA test result often leads to more tests such as a biopsy, which carries risks of bleeding, infection and urinary incontinence.
At this time, the task force says there are "no screening tests that have been proven to accurately identify prostate cancer." But, it adds, there are several tests being developed to improve the accuracy of PSA screening.
Meanwhile, the U.S. Preventive Services Task Force recommends that men between the ages of 55 and 69 speak with their health-care provider about whether they should get screened.
Why wasn't Biden's cancer spotted sooner?Experts say because there aren't many obvious symptoms, it's easy for prostate cancer to fly under the radar.
In February 2024, Biden had his last annual physical as president. At the time, his doctors said that "this year's physical identifies no new concerns."
Dr. Dana Rathkopf, a medical oncologist at New York's Memorial Sloan Kettering Cancer Center, said while she doesn't know the specifics of the case, she doesn't believe this diagnosis was missed during an earlier exam.
"Cancer cells are chaotic," she said in an interview with CBS News. "There are many people that have access to [the] highest levels of care and undergo regular screening and still get diagnosed with advanced disease."
Black said if Biden had been tested, it's possible his PSA levels were "normal."
"Sometimes the aggressive prostate cancers don't make as much PSA," he said.
What does treatment include?Prostate cancer that is in the early stages and not spreading will likely only be monitored, said the University of Calgary's Dickinson. It might not end up being harmful, he said, and so treating it wouldn't be helpful to the patient.
Meanwhile for higher-risk cases, where the PSA is high but the cancer is limited to the prostate, Black said surgery or radiation is usually recommended.
In cases where the disease has spread, he said radiation is often used alongside hormone therapy.
Hormone therapy lowers the amount of certain hormones in the body that would usually help prostate cancer cells grow. By doing this, prostate cancers can shrink or grow more slowly.
WATCH | Vancouver Prostate Centre director comments on Biden's diagnosis:Dr. Peter Black, a urologist and director of the Vancouver Prostate Centre, speaks about former U.S. president Joe Biden's prostate cancer diagnosis.This is the type of treatment being looked at for Biden, and while Black said it usually responds in the beginning, it's a matter of how long it will continue to work.
Without knowing all the details of Biden's case, Black said typically men with a similar diagnosis live about five years with current treatments.
The five-year survival rate for people who are in the first three stages of the disease is close to 100 per cent, according to Statistics Canada.
But if diagnosed at Stage 4, which is when the cancer has spread beyond the prostate, the survival rate for the next five years drops to 41 per cent.