WASHINGTON, D.C., USA — Former President Joe Biden’s team has revealed the former president has a “more aggressive form” of prostate cancer, sparking many questions about the diagnosis.

Biden was seen last week by doctors after experiencing urinary symptoms. A prostate nodule was found during the exam and had been sent away for additional testing. He was officially diagnosed with prostate cancer Friday, with the cancer cells having spread “to the bone,” a spokesperson said. 

The announcement of his diagnosis came Sunday. 

Prostate cancer is the most common cancer and the second leading cause of cancer death among men in the U.S., according to the American Cancer Society. 

Prostate cancers often aren’t weighed in typical “stages” like other cancers. Instead, they’re given a “Gleason score” that measures how the cancerous cells look compared with normal cells on a scale of 1 to 10. Biden’s score of 9 suggests his cancer is among the most aggressive, as his office’s spokesperson said. 

When prostate cancers need hormones to grow, as in Biden’s case, they can be susceptible to treatment that deprives the tumors of hormones. However, his cancer has spread to the bone, or metastasized. Metastatic cancers are more difficult to treat as they’re not localized to one area or organ. 

The overall prognosis for prostate cancer is among the best of all cancers, according to Johns Hopkins Medicine. However, when the prostate cancer has metastasized, or spread to other parts of the body, the average five-year survival rate is 28%, according to Johns Hopkins Medicine. 

“It’s very treatable, but not curable,” Dr. Matthew Smith of Massachusetts General Brigham Cancer Center told the Associated Press. “Most men in this situation would be treated with drugs and would not be advised to have either surgery or radiation therapy.”

Biden’s spokesperson said Sunday the former president and his family are “reviewing treatment options with his physicians.” No additional information on his diagnosis was announced. 

Prostate cancer, like many other cancers, is a growth of cells, according to the Mayo Clinic. The prostate is a small gland found just below the bladder and is part of the male reproductive system, helping make semen. 

Symptoms can include, but are not limited to: blood in the urine or the semen and bladder problems like needing to urinate more often or having difficulty doing so. In later stages of prostate cancer, people may also feel back and bone pain, erectile dysfunction, limb weakness and weight loss. 

Anyone with a prostate can get prostate cancer, but there are a variety of risk factors. 

• Age – Men over 50 have a higher chance of being diagnosed with prostate cancer. More than half of prostate cancers are found in men older than 65, according to the American Cancer Society. Biden is 82. 
• Health – Smoking, diet, chemical exposures and other risk factors can increase the chance of being diagnosed with prostate cancer. 
• Race, ethnicity and genetics also impact the likelihood of prostate cancer, according to the American Cancer Society.

Health experts suggest getting prostate cancer screening tests around 50 years old. Those with increased risk factors are encouraged to contact their doctors and screen earlier. 

Prostate exams can include blood tests and rectal exams. 

The Associated Press contributed to this report.