News reports covering a prostate cancer study recently in the New England Journal of Medicine have all pretty much come out with the same message: men diagnosed with prostate cancer who had radical surgery did much better than men who were assigned to “watchful waiting” after they were diagnosed.

But guess what? There’s a critical fact that seemed to be missing in much of the coverage I saw. And that fact is this: The men who were given the “watchful waiting” as described in the study never received any curative treatment. Let me repeat: no curative treatment. That is a much different approach to watchful waiting than we currently recommend in the United States, where watchful waiting after a diagnosis of prostate cancer usually means offering curative treatment when the prostate cancer changes its behavior.

The study was performed in Sweden, Iceland and Finland. Between 1989 and 1999, 695 men were entered into the study after they were diagnosed with prostate cancer. Half were assigned to undergo a radical surgical removal of the prostate gland, and half were assigned to “watchful waiting.”

Now, watchful waiting today means we watch, and if a patient’s prostate cancer changes its characteristics, we act. But in this study, the watchful waiting group was followed with routine medical care and no specific program to regularly monitor and treat if the local prostate cancer was getting worse. And indeed, none of those men (294 stayed in the group) received any curative therapy. They did receive treatment if their prostate caused trouble with their urine flow or had other symptoms, and some were started on medicines if their cancer spread or their doctor thought it might be a good idea. But if the cancer grew, it was not treated for cure.

In a sense, looking back on what we know now — that we can watch the prostate cancer and take more action if it starts to change — the study was effectively designed in a way that increased the potential for surgery to do better than no treatment at all. It didn’t use watchful waiting as we currently practice it, which is intended to offer curative therapy to those men who need it. (It’s important to understand that the study itself was done at a time where there was a question whether surgery made a difference in outcome. Interestingly, based on the results of some other recent studies, that question remains an active one today.)

To reiterate: Today, active surveillance or watchful waiting means if you have a small prostate cancer that appears to be less aggressive when viewed under the microscope and you are (usually) an “older” man, then you may do just as well by not doing anything-for the time being-than you would if you had intensive surgical or radiation treatment right away. Your doctor will check your PSA regularly, see you often, and periodically re-biopsy your prostate.

The reason your doctor will do all of that is because if your prostate cancer changes its “stripes” by becoming larger, or more aggressive, your doctor will then offer you curative therapy, such as surgery or radiation. You are both still focused on cure. In the study reported this week, there was no focus on cure for the men in the watchful waiting group. That is a real difference between what was done in this study compared to the way we treat prostate cancer today

So before you believe what you read, and assume your doctor is not acting in your best interest when they recommend watchful waiting instead of surgery or radiation for your prostate cancer, remember that a lot has changed since this newly reported research was started back in the late 20th century. We know much more about prostate cancer and how it behaves. We also know that some prostate cancers may well benefit from treatment, while others if left alone will probably not cause harm.

About the best thing we can say about this study is it is applicable to men treated the way we used to treat prostate cancer. But considering how much better we understand and implement watchful waiting, this study should not be used to encourage surgery for every man diagnosed with prostate cancer.

J. Leonard Lichtenfeld is deputy chief medical officer, American Cancer Society. He blogs at Dr. Len’s Cancer Blog.