By Dr. Shahar Madjar

I was planning to write about an entirely different subject. However, the breaking news caught me unprepared: Joe Biden, the 46th president of the United States, has been diagnosed with aggressive, metastatic prostate cancer. The announcement was made on Friday, May 16, 2025. Joe Biden is 82. And the question is: how was such a diagnosis missed–and who is to blame?

Let me tell you a bit about prostate cancer. It is the second most commonly diagnosed cancer in men (after skin cancer). The lifetime risk for men being diagnosed with prostate cancer is about 1 in 8. It is also the second leading cause of cancer death in men (after lung cancer).

Most men diagnosed with prostate cancer are asymptomatic. The disease is typically detected through a simple blood test called PSA, short for Prostate-Specific Antigen.

Here is one problem: PSA is not a perfect test. Unlike a pregnancy test, which clearly states whether a woman is pregnant, a PSA test doesn’t provide a definitive ‘yes’ or ‘no’ answer. Instead, it indicates a degree of suspicion. The higher the PSA, the greater the likelihood of prostate cancer–but a high PSA doesn’t necessarily mean cancer is present. Benign prostatic hyperplasia (enlargement of the prostate, common with aging), inflammation, and infection are all common causes of elevated PSA levels.

According to news reports, Mr. Biden’s last PSA was drawn in 2014, when he was 71. His prostate cancer was diagnosed after a physical exam revealed a small prostate nodule. Only then was a PSA test performed, followed by further evaluation, and the full extent of the disease became apparent.

Why wasn’t Biden’s PSA checked for over a decade? Should his doctors be blamed for the missed diagnosis?

Before assigning blame, here are a few important things to understand about prostate cancer:

First, the definitive diagnosis of prostate cancer requires a prostate biopsy, in which tissue samples are taken and analyzed. The procedure is unpleasant and carries risks–albeit small–of bleeding, infection, and even sepsis.

Second, most men diagnosed with prostate cancer have slow-growing disease. They are more likely to die with prostate cancer than from it. Advanced diagnostic tools such as MRI and molecular markers can reduce the detection of these indolent tumors, but screening still carries the risk of uncovering cancers that would never have caused harm. This phenomenon is known as overdiagnosis.

Third, overdiagnosis often leads to overtreatment–unnecessary surgery or radiation–that can significantly impact quality of life. Side effects include urinary incontinence, erectile dysfunction, and bowel dysfunction.

Why, then, screen at all?

One large-scale European trial showed that PSA screening can reduce prostate cancer mortality by 21-30%. For many, screening offers reassurance and peace of mind. But that comes at a steep price: the number of men needed to be screened to save a single life is staggering. According to that same study, 781 men need to be screened, and 27 treated, to prevent one death from prostate cancer.

Finally, we must consider the competition from other potentially lethal conditions. As men age, they accumulate various medical issues. Prostate cancer is just one of many diseases that can be fatal. Heart disease, stroke, and other cancers often pose greater threats. As a result, the older a man is, the less likely he is to benefit from prostate cancer screening. Most medical organizations recommend stopping PSA screening at a certain age or when life expectancy falls below 10 to 15 years.

Mr. Biden’s doctors may have done everything right. I want to believe they discussed not just the potential benefits but also the risks and limitations of PSA screening. They may have engaged in informed, shared decision-making with Mr. Biden and his family. Their decision may have followed the latest guidelines from major medical organizations. Mr. Biden’s age and overall health were likely taken into careful account. Together, they may have made a shared decision to discontinue PSA testing.

Despite the advanced stage of his cancer, effective treatments for metastatic prostate cancer exist. With the right care, President Biden may still live long enough to die of old age–not of prostate cancer.