A study published Wednesday in the New England Journal of Medicine found that certain men with prostate cancer lived 2.9 years longer if they had their prostate removed, compared to men with “watchful waiting” as their treatment. 

Both the study and coverage of it has alarmed doctors who fear it will be misinterpreted. 

“My fear is that someone will read a headline that says that surgery improves outcomes for prostate cancer as opposed to watchful waiting,” says Len Lichtenfeld, MD, interim chief medical and science officer for the American Cancer Society.

The research is noteworthy because it starts back in 1989, so scientists studied the earliest participants for 29 years.

“Following people for 25 to 30 years is not something that’s reported very often,” Litchfield says, adding that while it’s interesting it “clearly should not be interpreted to mean that surgery is better than watchful waiting.”.

 His main fear: “I’d be very concerned if someone with a diagnosis read this and said, ‘I want surgery instead of watchful waiting’.”

29 years is a long time

There’s nothing inherently wrong with the study. But the length of time since it began makes it problematic when it comes to deciding on treatments now. 

“Trying to compare this study to what is done in the U.S. today is not really a reasonable comparison,” Lichtenfeld says. “It’s an entirely different world today in terms of how we diagnose and treat cancer.” 

When the study started, most men were diagnosed with prostate cancer in one of two ways. They noticed symptoms like trouble urinating, blood in the urine or semen, or erectile dysfunction. Or, their doctor felt a mass during a rectal exam.

Those signs and symptoms typically come along once prostate cancer is relatively advanced. 

Today, most cases are discovered much sooner thanks to prostate-specific antigen (PSA) screening, a blood test that can identify prostate cancer well before symptoms or masses appear. It was FDA approved as a screening test beginning in 1994. 

A good option

Now, most men with small, low-grade cancers can be watched and tested periodically. That’s because prostate cancer tends to progress slowly—so slowly that most men who have it die of something else. 

That was true even among the research participants—80% died within the study’s 29 years, and 68% of them died from causes other than prostate cancer.

It’s important to note that watchful waiting doesn’t mean surgery won’t ever be necessary. Changes in PSA levels or other concerns might make surgery a viable option at some point for men with prostate cancer. But today, surgery is less likely to be a first-line treatment for most men.