Should men be screened for prostate cancer?

SEEN THROUGH the cold lens of statistics, Joe Biden’s statement on May 18th that he had been diagnosed with prostate cancer is not all that surprising. In America prostate cancer is the second-most commonly diagnosed sort behind breast cancer. (In England it takes the top spot.) Around one man in eight will be diagnosed in their lifetimes. As with most cancers age is the biggest risk, though family history and black ethnicity are others. Younger men can get unlucky and suffer, too. In 2024 Sir Chris Hoy, a British Olympic cyclist, announced that he had an aggressive and terminal form of the disease. Ultra-fit and aged just 48 at the time, Sir Chris was not, on the face of it, at high risk.

Such high-profile cases feed a long-running debate among doctors about whether middle-aged men should be screened for the disease. After Sir Chris’s announcement England’s health service said it would review its advice on the merits of screening, which it currently does not recommend. Mr Biden’s office has said that the former president was last screened in 2014. Screening for such a common cancer may seem like a no-brainer. But many doctors and medical organisations are less sure.

One problem is that the main test, which measures levels of a chemical called prostate-specific antigen (PSA) in the blood, is not very reliable. High PSA levels can be a sign of prostate cancer. But they can also be a sign of vigorous exercise or recent sexual activity. The false-positive rate—the percentage of men who do not have cancer but will get a high reading—is around 75%. The false-negative rate (in which the test mistakenly clears men who do have cancer) is thought to be around 15%. Doctors therefore double-check high PSA levels with a biopsy.

If cancer is found, about 20% of cases will need aggressive treatment, says Naser Turabi of Cancer Research UK, a charity. For most men a prostate tumour will grow either slowly or not at all, meaning they will die with the cancer but not of it. (For that reason many doctors think men over 70 should not generally get tested.) And treatment risks nasty and permanent side-effects, including urinary incontinence, bowel problems and impotence. Many doctors worry that mass screening would lead to over-diagnosis and over-treatment of cancers that are very unlikely to be fatal.

A big British trial found the 15-year survival rate for men with cancers that had not spread was virtually identical, at around 97%, regardless of whether they had surgery, radiation therapy, or no treatment at all beyond keeping a wary eye on the cancer. Such “watchful waiting” is the most conservative approach, but even that can be difficult: doctors report many patients become unable to bear the thought of having cancer, even if it is not life-threatening, and opt for treatment despite the risks.

All this means opinions differ among both doctors and governments about the wisdom of routine screening. The trade-offs may shift as technology advances. These days many men with high PSA levels will be offered an MRI scan before deciding on a biopsy. Other scientists hope that genome sequencing could help assess a patient’s risk. But the long survival time for sufferers means hard data on what does and doesn’t improve survival lag years behind what happens in the clinic today. For middle-aged men the best, if unsatisfying, course of action is probably to ask your doctor, think carefully—and consider the possibility of some tricky trade-offs if you go ahead. ■