Have you ever wanted something for such a long time that when it finally arrived you found yourself terribly disappointed?
Maybe that's the best way I can summarize my feelings about two studies reported today in the New England Journal of Medicine on the topic of prostate cancer screening and whether it really makes a difference.
For years we have been saying that there wasn't sufficient evidence to prove that screening for prostate cancer saved lives. That was almost always followed by a statement that we were waiting for the results of two trials in the United States and Europe. "They will show us the answer," we said.
In the meantime, millions of men continued to get tested and undergo treatment, even though no one could really say if we were saving lives, or just sending millions more men to unnecessary treatment with all sorts of side effects.
Well, my friends, the waiting is over. The day has arrived. And I don't know that we now have any better idea whether prostate cancer screening actually works.
Prostate cancer in the United States in 2008 was estimated to occur in 186,320 men. The American Cancer Society estimated that 28,660 men would die from prostate cancer in the United States in 2008.
Prostate cancer is the most common cancer in men, accounting for 25 percent of cancers diagnosed in men in 2008. It is the second leading cause of cancer death in men -- behind lung cancer -- accounting for 10 percent of cancer deaths. A man in this country has a one in six chance of being diagnosed with prostate cancer during his lifetime, with most of those diagnoses occurring at ages 70 and older.
Importantly, and not mentioned as often, is the fact that only one in 34 men will die of the disease.
The two research papers in the New England Journal of Medicine describe early results from two different trials -- one in the United States and one in Europe -- that were designed to find out whether tests to find prostate cancer early reduced deaths from the disease.
In the United States trial, 76,693 men between the ages of 55 and 74 years were randomly assigned to be screened or receive "usual care" from 1993 to 2001. The men in the screened group had annual PSA testing for six years and digital rectal examinations every year for four years.
The good news is that the men in this trial who were in the screened group did a reasonably good job of following the directions of the trial: 85 percent of them had their PSA blood test, and 86 percent did the rectal exam as requested.
The not so good news is that by the sixth year of the trial, 52 percent of the men in the control group -- who were left to their own devices as to whether they should get the PSA blood test -- had the test. Forty-six percent of these men had a rectal exam.
What that leaves us with is a clinical trial where the men who were asked to get screened did get screened. And of the men who were not told to get screened, about half of them got screened anyway.
The end result was that after seven years of follow-up, there were more cancers diagnosed in the screened group (no surprise there: go looking for prostate cancer in a man and you have a pretty good chance of finding it) compared to the "control group," but the deaths were a bit higher in the screened group compared to the supposed no-screening group.