NEW YORK – The rate of prostate cancer among active-duty U.S. Air Force members has been several times higher in recent years than it was 20 years ago, a new study finds.
Researchers believe that the trend is not a sign of any increase in servicemen's actual risk of the cancer. Instead, they think that wider use of prostate cancer screening may be catching some early cancers that once went undetected.
That would match the pattern seen among U.S. men generally. After PSA blood tests came into use for prostate cancer screening in the mid-1990s, the number of men diagnosed with the cancer rose.
However, PSA screening is controversial. Because prostate cancer is often slow-growing and may never progress far enough to threaten a man's life, finding and treating early tumors can do more harm than good for some. Treatment side effects include impotence and incontinence.
It's estimated that such "low risk" tumors account for 40 to 50 percent of prostate cancers diagnosed among U.S. men.
In the new study, researchers found that between 2005 and 2008, the rate of prostate cancer among white active-duty Air Force servicemen was three times higher than it was between 1991 and 1994.
Among African Americans, the rate rose 11-fold, according to findings published in the Journal of Urology.
The absolute numbers were still low. Among white men in recent years, the rate was about 26 cases per 100,000 servicemen per year; among black men, the rate was 39 per 100,000.
But both of those rates were higher than what was seen during the same period among U.S. men in general in the same 35 to 64 age range. Most of the cancers in servicemen—62 percent—were low risk, which is also higher than the U.S. norm.
The difference is probably because Air Force members are more likely to be screened for prostate cancer, according to researcher Dr. Marc Goldhagen, of the U.S. Air Force School of Aerospace Medicine in San Antonio.
"I believe that the consensus from all involved with this study is that the increased incidence found in our population was due to increased screening," Goldhagen told Reuters Health in an email.
The Air Force requires yearly physical exams. That does not automatically include PSA testing, since experts recommend against routine screening.
But men who see a doctor regularly would presumably have more chances to discuss PSA screening, or possibly have it recommended to them because they are at increased risk—because of family history, for example.
When it came to treatment, Goldhagen's team found, nearly all active-duty servicemen with low risk cancer (92 percent) opted to have surgery, rather than delay treatment in favor of "active surveillance."
Active surveillance means that a man's cancer is monitored over time with PSA tests and biopsies. There is growing evidence that for older men with low-risk prostate cancer, active surveillance is a good option—discouraging "overtreatment" without increasing their risk of dying from the cancer.
But it's not surprising at all that so many Air Force servicemen with low-risk cancer would have surgery, according to Dr. Patrick C. Walsh, a professor of urology at Johns Hopkins University School of Medicine in Baltimore.
Walsh, who was not involved in the study, said he sees no evidence of over-treatment.
He pointed out that the average age at diagnosis was just 48. "When a young man is diagnosed with prostate cancer, surgery is the best option," Walsh told Reuters Health.
It's not yet known whether active surveillance is safe for men in their 40s and 50s, according to Walsh. And on top of that, he said, they would face many years of repeated biopsies—which can cause the same side effects as surgery, including incontinence and impotence.
Goldhagen also pointed out that a man in his 40s, even with low-risk cancer, would have many years of life ahead during which the tumor could progress. And doctors have no way of predicting which low-risk cancers will ultimately progress.
While the researchers believe increased screening is the reason for the rising rate of prostate cancer among service members, they had no information on whether a man's cancer was detected through screening, or because he was having symptoms that prompted testing.
They say more research is needed to nail down the extent to which screening accounts for the rising rates of prostate cancer seen in Air Force servicemen.