Joe Biden's 'aggressive' cancer diagnosis explained as Trump and Obama speak out

Joe Biden's 'aggressive' cancer diagnosis has been explained as former presidents issue well-wishes.

On Sunday (May 18), the office of the 82-year-old and former president released a statement, confirming Biden has been diagnosed with prostate cancer which has spread to the bones.

Biden's reps confirmed the former 46th president of the United States was seen by medics last week for urinary symptoms who found a new 'prostate nodule.'

The statement added: "On Friday he was diagnosed with prostate cancer, characterized by a Gleason score of 9 (Grade Group 5) with metastasis to the bone.

"While this represents a more aggressive form of the disease, the cancer appears to be hormone-sensitive which allows for effective management.

"The president and his family are reviewing treatment options with his physicians."

Biden's office has confirmed the diagnosis (Bruce Glikas/WireImage)

What is prostate cancer?

According to the American Cancer Society, prostate cancer is the most common cancer in men in the US other than skin cancer, affecting around one in eight men.

The Mayo Clinic describes it as a 'growth of cells' that start in the prostate, a small gland found just below the bladder that produces semen.

It is usually detected early and grows slowly, with the clinic adding that most people diagnosed with prostate cancer are 'cured.'

Essentially, many men can live with it for decades without needing treatment, though symptoms don't always appear until the cancer is already developed and advanced.

Symptoms include needing to urinate more frequently, difficulty in peeing, straining or taking a long time while peeing, weak flow, and/or blood in urine or in semen, according to the NHS.

Signs that it may have spread further include bone and back pain, a loss of appetite, testicle pain and weight loss.

Prostate cancer affects the male reproductive system (Getty Images)

What is the Gleason score?

The Gleason score is used by medics to grade prostate cancer, according to Cancer Research.

The grade infers how much the cancer cells look like normal cells and how likely they are to grow or how aggressive they appear.

There are five grade groups with Grade Group 1 considered the least aggressive while Grade Group 5 is the most.

As Biden has a Gleason score of nine, he's in the highest category, meaning the cells look very abnormal and is likely to grow quickly.

Biden with his grandson, Beau and wife, Jill, after his farewell address from the White House in January (Mandel Ngan - Pool/Getty Images)

What does the diagnosis mean for Joe Biden?

Biden presented to doctors with one of the most common symptoms of prostate cancer, urinary issues, though it appears the cancer has already spread to his bones.

While it is 'not uncommon' for older men in their 80s to be diagnosed with prostate cancer, Biden's Gleason grade indicates it is 'most advanced than most men would encounter', Dr Ryan Clearly, a urologist at MedStar Health told the BBC.

Although Biden's exact case is unknown, Dr Clearly added: "Generally about a third of patients will still be alive after five years of metastatic prostate cancer."

Doctors also said Biden's cancer is hormone-sensitive, meaning they can effectively 'manage' his prognosis by taking medications that block or lower the amount of hormones in the body to prevent further growth.

Dr Jamin Vinod Brahmbhatt, a urologist at Orlando Health Medical Group, told the news outlet that while such treatments are not 'curative' to the cancer, there are 'more medical options to stabilise the patient and control the cancer, but it never gets rid of the cancer completely.'

Biden and his family are said to be reviewing treatment options.

Obama and Trump have both issued statements (MANDEL NGAN/AFP via Getty Images)

What has Donald Trump and Barack Obama said about Biden's cancer?

The 44th POTUS, Barack Obama, issued a statement after hearing the news.

He wrote in a post on Twitter: "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."

Obama's comment comes as Biden was passionate about tackling the cancer death rate while in office, following the death of his eldest son Beau who died of glioblastoma brain tumor in 2015.

Biden's predecessor and successor, President Trump also sent a message of support, writing on Truth Social: "Melania and I are saddened to hear about Joe Biden’s recent medical diagnosis.

"We extend our warmest and best wishes to Jill and the family, and we wish Joe a fast and successful recovery."