Key facts about prostate cancer following Biden's diagnosis

What to know about prostate cancer

The precise causes of prostate cancer are largely unknown, but the Centers for Disease Control and Prevention notes that the common risk factor is age. "The older a man is, the greater the chance of getting prostate cancer," it says.

• The disease "starts when cells in the prostate develop changes in their DNA," according to a Mayo Clinic post. "In cancer cells, the DNA changes give different instructions. The changes tell the cancer cells to grow and multiply quickly. Cancer cells can keep living when healthy cells would die. This causes too many cells."
• Prostate cancer "usually grows very slowly," per the NCI.

By the numbers: NCI modeling estimates that prostate cancer constitutes 15.4% of all new cancer cases and that 313,780 people will contract the disease this year.

• "The rate of new cases of prostate cancer was 120.2 per 100,000 men per year, according to the institute. "The death rate was 19.2 per 100,000 men per year. These rates are age-adjusted and based on 2018–2022 cases and 2019–2023 deaths."

What are the symptoms of prostate cancer?

Biden was examined last week over "a new finding of a prostate nodule after experiencing increasing urinary symptoms" and he was diagnosed Friday, according to an emailed statement from his office.

• Urinary issues can occur in early and late-stage prostate cancer, per an American Cancer Society post.

Zoom in: "Early prostate cancer usually causes no symptoms," according to the U.S. nonprofit that's dedicated to eliminating cancer. "While not common," the American Cancer Society notes that symptoms of early prostate cancer may include:

• Problems urinating, including a slow or weak urinary stream or the need to urinate more often, especially at night.
• Blood in urine or semen.

"Advanced prostate cancer means it has grown larger and has possibly spread to other areas," the American Cancer Society says. When this happens, patients may experience problems with urination and blood in their urine or semen. Other symptoms may include:

• Erectile dysfunction.
• Pain in areas of the body including the hips and spine from cancer that has spread to the bones.
• "Weakness or numbness in the legs or feet, or even loss of bladder or bowel control, from cancer in the spine pressing on the spinal cord," per the American Cancer Society.
• Patients may experience weight loss and/or fatigue.

What is a Gleason score?

Biden's cancer is "characterized by a Gleason score of 9 (Grade Group 5)," according to his office.

Between the lines: The Gleason grading system helps medical professionals assess how aggressive prostate cancer is in a patient and is calculated after tissue samples have been studied under a microscope, per a Cleveland Clinic post.

• Gleason scores range from 2 to 10 and a grading that's 5 or lower isn't considered cancer, but "scores from 6 to 10 are considered cancer," the Mayo Clinic notes.
• Men with a Gleason score of 8 tend to do better than those with a grading of 9 or 10, even though they're all "high-grade" cancers, according to the American Cancer Society.

Prostate cancer treatments and prognosis

99% of patients diagnosed with cancer that hasn't spread outside of their prostate live at least five years following diagnosis, per the Mayo Clinic.

Yes, but: The clinic says that for patients whose cancer has metastasized, or spread outside of their prostates 32% are alive five years later.

• "For cancers that grow fast and spread, common treatments include radiation and surgery," according to the clinic.
• Other treatments may include hormone therapy, or androgen deprivation therapy (ADT), which is employed in an effort to stop hormones from "fueling prostate cancer cell growth," per the American Cancer Society.

The bottom line: "This news is a reminder about the tragic impact of prostate cancer in the U.S., where about one in eight men will be diagnosed over their lifetime with prostate cancer," per a Sunday statement from the society in response to Biden's diagnosis.

• "Early detection is key, and we are concerned given the 5% year-over-year increase in diagnosis of men with more advanced disease. We can and must do more to prevent late-stage diagnosis and death from prostate cancer."

Go deeper: Trump, lawmakers wish Biden well after cancer diagnoses

Editor's note: This article has been updated with the American Cancer Society's statement responding to former President Biden's diagnosis.