Former United States President Joe Biden has been diagnosed with an aggressive form of prostate cancer that has spread to his bones.
Biden, 82, was diagnosed on Friday after doctors discovered a nodule on his prostate, his office said in a statement released on Sunday.
The statement added that the cancer had “a Gleason score of nine (Grade Group 5)” on a scale that goes up to 10, signifying that Biden’s cancer is highly aggressive.
Here is what you need to know about Biden’s diagnosis:
What is the Gleason Index?
Prostate cancer is confirmed through a biopsy, a procedure in which tissue is collected to check for signs of disease.
The Gleason score, also known as the Gleason index, is a grading system that assesses how aggressive prostate cancer is by examining the appearance of cancer cells under a microscope.
A pathologist examines prostate tissue and assigns two Gleason grades: one for the most common pattern of cancer cells and one for the second most common pattern.
Each grade falls between 1 and 5, where one indicates tissue that closely resembles normal cells and five represents the most abnormal appearance.
These two grades are added together to get the Gleason score, which ranges from 2 to 10. A 9 or 10 score is seen as a very aggressive form of cancer.
What is prostate cancer ?
Prostate cancer ranks as the most frequently identified cancer in American men, according to the National Cancer Institute (NCI) in the US. Globally, it is the second most common form of cancer among men and fourth most common overall, according to the World Cancer Research Fund.
This type of cancer affects the prostate, a small gland located near the male bladder that contributes to the production of semen.
Although the exact causes remain unclear, some evidence suggests that a diet high in fat could be a contributing factor.
So far in 2025, more than 313,000 new cases of prostate cancer have been diagnosed in the US, the NCI said on its website. That’s nearly three times higher than the second most common type of cancer among American men, lung cancer, at 110,000 new cases. The US has the highest number of recorded cases of prostate cancer in the world.
According to the Centers for Disease Control and Prevention (CDC), 13 out of 100 American men will get the disease, citing age as the “most common risk factor”.
Symptoms include urinating often, difficulty urinating, a burning sensation while urinating, and blood in the semen or urine, the CDC said.
How will Biden be treated?
According to the statement from Biden’s office, “the cancer appears to be hormone-sensitive, which allows for effective management”.
“The President and his family are reviewing treatment options with his physicians,” it added.
A hormone-sensitive prostate cancer needs androgens, a group of male sex hormones, to grow – most of which are made in the testicles.
The American Cancer Society notes this specific type of prostate cancer can be treated using androgen deprivation therapy, which reduces the level of androgens to “stop them from fuelling prostate cancer cell growth”.
Johns Hopkins Medicine said on average the five-year survival rate for prostate cancer is nearly 100 percent after diagnosis but drops to 28 percent if the cancer has metastasised as it has done in Biden’s case.
It also notes that the 10-year and 15-year survival rates are 98 percent and 95 percent, respectively.
Outcomes have improved in recent decades, and patients can expect to live with metastatic prostate cancer for four or five years, said Matthew Smith of Massachusetts General Brigham Cancer Center.
“It’s very treatable but not curable,” Smith told The Associated Press news agency.
“Most men in this situation would be treated with drugs and would not be advised to have either surgery or radiation therapy.”
How are people reacting to Biden’s diagnosis?
Longtime foe President Donald Trump, whom Biden defeated in the 2020 election, said in a post on his social media platform, Truth Social, that he wished Biden “a fast and successful recovery”.
Former President Barack Obama said his thoughts and prayers were with Biden, who was Obama’s vice president.
“Nobody has done more to find breakthrough treatments for cancer in all its forms than Joe, and I am certain he will fight this challenge with his trademark resolve and grace,” Obama posted on X.
Michelle and I are thinking of the entire Biden family. Nobody has done more to find breakthrough treatments for cancer in all its forms than Joe, and I am certain he will fight this challenge with his trademark resolve and grace. We pray for a fast and full recovery.
— Barack Obama (@BarackObama) May 18, 2025
Kamala Harris, the Democratic Party’s presidential candidate in 2024 and Biden’s vice president, said she was “saddened” to hear of Biden’s diagnosis.
“Joe is a fighter – and I know he will face this challenge with the same strength, resilience, and optimism that have always defined his life and leadership,” Harris wrote on social media.
Former US Secretary of State and Senator Hillary Rodham Clinton said she was “thinking of the Bidens as they take on cancer, a disease they’ve done so much to try to spare other families from”.
Biden’s oldest son, Beau, died from brain cancer in 2015, aged 46. After Beau’s death, Obama in 2016 launched the Cancer Moonshot Initiative to help speed up cancer research to try to make advances in the diagnosis, prevention and treatment of the disease.
Obama appointed Biden to lead the initiative.
