Oct. 19, 2005 (Denver) -- The American Cancer Society and the American Urological Association have both backed annual PSA (prostate-specific antigen) screening -- a blood test -- and digital rectal exams starting at age 50 for men with average risk.
For men with a higher risk (African-Americans and those with a family history of prostate cancer) the American Cancer Society recommends starting at age 40.
Screening for prostate cancer is one of the most controversial issues in men's health today. The U.S. Preventive Services Task Force says there is not enough evidence to recommend for or against such routine screening. And many doctors have spoken out -- loudly -- against routine screening.
Now, a new study, presented Wednesday at the annual meeting of the American Society for Therapeutic Radiology and Oncology (ASTRO), suggests that men who have yearly screening are three times less likely to die from prostate cancer than men who don't have the annual tests.
"This simple yearly blood test would appear to discover prostate cancers when they are more curable and may lower the risk of dying from prostate cancer," says researcher Jason Efstathiou, MD, PhD, of the Harvard Radiation Oncology Program.
The study suggests that over a 10-year period, 11.3% of men who don't have annual PSA screens will die from the disease, compared with only 3.6% of those who do have yearly tests, he tells WebMD.
PSA Debate Continues
But don't look for the findings to end the debate over annual prostate screens anytime soon. For that, "we really need the results of three massive trials going on in the U.S. and Europe," Efstathiou says. Those findings are due out in 2008.
The reason: Those large trials are following men -- half of whom get annual screens and half of whom don't -- to see how many develop prostate cancer and die from the disease over time. In contrast, Efstathiou studied a group of men who had already had surgery for prostate cancer. Then, he looked back to see how many had had annual screens before their operation. Such studies are open to a slew of problems, as doctors don't really know that much about the men and their other risk factors for the disease.
"What our findings do give us are clues into what I expect the large trials will show," Efstathiou says. "If those studies confirm the results of this trial, annual PSA testing will become standard.
Theodore Lawrence, MD, chairman of the board of ASTRO and chairman of radiation oncology at the University of Michigan School of Medicine in Ann Arbor, agrees.
"There's no question that PSA can detect early-stage prostate cancer, but the question is whether it will improve survival and lower deaths from prostate cancer," he tells WebMD.
There are other problems with the strategy as well, he notes. While cancer causes PSA levels to increase, PSA levels can also rise with benign conditions such as prostate enlargement or benign prostatic hyperplasia (BPH). And even when the PSA increase is due to cancer, the cancer could be so slow-growing as to never be life-threatening.
PSA Screens Linked to Better Prognosis
The researchers studied 1,492 men who were diagnosed with prostate cancer and underwent surgery to remove a cancerous prostate gland between 1988 and 2002. Of the total, 841 men had yearly annual PSA screens before their diagnosis.
The previously screened men fared better on almost every score:
- Their cancers were discovered earlier, when they're more curable, Efstathiou says.
- They were less likely to have aggressive cancers at the time of diagnosis.
- The screened men were at lower risk of relapse or dying after their operation. Only 5% of the screened men had their PSA levels double within three months after prostate cancer surgery, compared with 12% of the other men, Efstathiou says. Having PSA levels double in the three months after surgery is an indication that a person will succumb to the disease in the next 10 years, he says.
ASTRO's Lawrence agrees that the so-called PSA doubling time is a "reasonable surrogate for survival." But it's still a surrogate, not the same as following men to see how many die over time, he says.
Prostate cancer is the second most common cause of cancer death among men, and about 30,000 men die from the disease each year.
Cons to Routine Prostate Cancer Screening
If your PSA is elevated, it doesn't mean that you have prostate cancer. Likewise, if your PSA is in the "normal" range, it doesn't guarantee that you are necessarily cancer-free.
Another drawback to routine testing is that abnormal values may lead to pain and risk of complications from unnecessary procedures related to prostate biopsies. There is also the risk of diagnosing and treating patients with very early-stage disease who may not have had any adverse effects from it if it had not been detected.
Despite the controversy surrounding mass routine testing, most medical groups agree that physicians should discuss the pros and cons of screening, diagnosis, and treatment with their patients. Such conversations would allow for more individualized risk assessment and allow for patient input into their care.