Explained | What a prostate cancer diagnosis like Biden's means for patients

Prostate cancer experts say that former President Joe Biden's diagnosis is serious. Announced on Sunday by his office, the cancer has spread to his bones. And it is Stage 4, the most deadly of stages for the illness. It cannot be cured.

But the good news, prostate cancer specialists said, is that recent advances in diagnosing and treating prostate cancer -- based in large part on research sponsored by the National Institutes of Health and the Defense Department -- have changed what was once an exceedingly grim picture for men with advanced disease.

"Life is measured in years now, not months," said Dr. Daniel Lin, a prostate cancer specialist at the University of Washington.

Dr. Judd Moul, a prostate cancer expert at Duke University, said that men whose prostate cancer has spread to their bones, "can live five, seven, 10 or more years" with current treatments. A man like Biden, in his 80s, "could hopefully pass away from natural causes and not from prostate cancer," he said.

Biden's office said the former president had urinary symptoms, which led him to seek medical attention.

But, Lin said, "I highly doubt his symptoms were due to cancer."

Instead, he said, the most likely scenario is that a doctor did an exam, noticed a nodule on Biden's prostate and did a blood test, the prostate-specific antigen test. The PSA test looks for a protein released by cancer cells, and can be followed up by an MRI. The blood test and the MRI would have pointed to the cancer.

In this moment, patients like Biden and others who develop metastatic prostate cancer diagnoses are more fortunate than patients in the past. There are about 10 new treatments for the disease, and they have markedly changed the picture.

The first line of attack is to cut off the testosterone that feeds prostate cancer. When Moul was starting out as a urologist in the 1980s, that was done by removing a man's testicles. Today, men have a choice of two drugs given by injection that block the testicles from making testosterone, or a pill that does the same thing.

But those drugs alone are not sufficient. So, doctors add any of three or four so-called androgen blockers that block testosterone that still manages to be produced in the testicles.

Some men, depending on how much cancer is in their bones, where the cancer tends to go, also have additional treatment, with chemotherapy or radiation.

There have also been improvements in diagnosis.

Until recently, doctors determined how much cancer was in the bones with scans that looked for inflammation. Now they have a more precise scan, called a prostate-specific membrane antigen (PSMA) PET scan. It uses a radioactive tracer that attaches to a marker on the surface of prostate cells. It allows doctors to spot the cancer much earlier, which means men with prostate cancer cells in their bones often have a much better prognosis -- because they can be treated earlier -- than men who had bone scans of just a few years ago.

Finally, if the medications that block testosterone, and the chemotherapy and radiation therapy, stop working, there are other drugs that can be used to quell the cancer.

Lin noted that the infusion of federal research money, with Biden's cancer moonshot effort, in large part led to this progress. Biden, he said, "was one of the first presidents to put cancer on the forefront."

As for Moul, he said he sees men Biden's age with Stage 4 prostate cancers on a regular basis and is much more optimistic now than ever before.

"We have a lot more tools in our toolbox," Moul said. "Survival rates have almost tripled in the last decade. I can't fathom how much change has taken place."