Simplifying the Decision for a Prostate Screening
Simplifying the Decision for a Prostate Screening - NYTimes.com
September 27, 2010
By TARA PARKER-POPE
One of the most difficult decisions a man makes about prostate cancer happens long before the diagnosis. Should he get a regular blood test to screen for the disease?
Screening for early detection of cancersounds like a no-brainer, but it’s not an easy choice for men considering regular P.S.A.tests, which measure blood levels of prostate-specific antigen and are used to detect prostate cancer. Though use of the test is widespread, studies show that the screening saves few, if any, lives.
While the test helps find cellular changes in the prostate that meet the technical definition of cancer, they often are so slow-growing that if left alone they will never cause harm. But once cancer is detected, many men, frightened by the diagnosis, opt for aggressive surgical and radiation treatments that do far more damage than their cancers would have, leaving many impotent and incontinent.
As a result, major health groups don’t advise men one way or the other on regular P.S.A. screenings, saying it should be a choice discussed between a man and his doctor.
So how does a man decide whether to get P.S.A. screening or not? Finally, some new research offers simple, practical advice — at least for men 60 and older.
Researchers at Memorial Sloan-Kettering Cancer Center in New York and Lund University in Sweden have found that a man’s P.S.A. score at the age of 60 can strongly predict his lifetime risk of dying of prostate cancer, according to a new report in the British medical journal BMJ.
The findings also suggest that at least half of men who are now screened after age 60 don’t need to be, the study authors said.
The researchers followed 1,167 Swedish men from the time they were 60 years old until they died or reached 85. During that time, there were 43 cases of advanced prostate cancer and 35 deaths in the group. The researchers found that having had a P.S.A. score of 2.0 or higher at the age of 60 was highly predictive of developing advanced prostate cancer, or dying of the disease, within the next 25 years.
About one in four men will have a P.S.A. score of 2.0 or higher at the age of 60, and most of them will not develop prostate cancer, said the study’s lead author, Andrew Vickers, associate attending research methodologist at Memorial Sloan-Kettering. But the score does put them in a higher-risk group of men who have more to gain from regular screening, he concluded.
The higher the score at age 60, the greater the long-term risk of dying from prostate cancer, Dr. Vickers and his colleagues found. Men with a score of 2.0 or higher at age 60 were 26 times more likely to eventually die of the disease than 60-year-old men with scores below 1.0.
Still, the absolute risks for men with elevated scores were lower than might be expected. A 60-year-old man with a P.S.A. score just over 2.0 had an individual risk of dying from prostate cancer during the next 25 years of about 6 percent, the researchers found. A 60-year-old man with a P.S.A. score of 5 had about a 17 percent risk.
“Most of those men are going to be absolutely fine,” said Dr. Vickers. “But they can be told they are at high risk and they need screening.”
Men with a P.S.A. score of 1.0 or lower at age 60 had a very low individual risk of death from prostate cancer over the next 25 years, the study found: just 0.2 percent.
“They can be reassured that even if they have prostate cancer or get it, it’s unlikely to become life-threatening,” said Dr. Vickers. “There’s a strong case that they should be exempted from screening.”
The advice is less clear for men with scores between 1.0 and 2.0 at the age of 60. They still have a very low individual risk of dying from prostate cancer, judging from the new data. The long-term risk of dying from prostate cancer ranged from about 1 percent to 3 percent for these men, and the decision to screen may depend on their personal views and family histories, Dr. Vickers said.
While the findings don’t answer all of the questions associated with P.S.A. screening, they should give peace of mind to sizable numbers of men who decide not to continue regular testing. The results also will reassure men who decide to continue with regular screenings that the benefits most likely outweigh the risks.
Dr. Eric A. Klein, chairman of the Glickman Urological and Kidney Institute at the Cleveland Clinic, said that he would like to see the findings of the new study independently confirmed, but that other studies also have suggested that the risk of cancer is low in men whose P.S.A. levels remain below 1.5 in their 50s and 60s.
“We are in the midst of a paradigm shift in screening and risk assessment that no longer relies on a simple P.S.A. cutoff to determine who should be biopsied,” Dr. Klein said.
P.S.A. screening is already not advised for those 75 and older, because the slow-moving nature of the disease means that a vast majority of men at that age are likely to die from something other than a newly detected prostate cancer. A major study last year confirmed that P.S.A. testing is not helpful for men with 10 years or less of life expectancy.
But the advice continues to be murky for younger men. In a large European study reported last year, 50- to 54-year-olds didn’t benefit from screening. But men ages 55 to 69 who had annual P.S.A. testing were slightly less likely to die from prostate cancer than those who weren’t screened.
The researchers who conducted the latest study also have investigated whether a man’s P.S.A. score at 50 can predict his long-term risk. In a 2008 report of 21,000 men published in the journal BMC Medicine, the researchers found that two-thirds of the advanced cancer cases that developed over 25 years were in men who had a P.S.A. score of 0.9 or higher at the age of 50.
Those findings can help younger men decide how intensely they want to screen for the disease. A man whose P.S.A. test shows him to be at low risk at age 50 may decide not to be retested again until the age of 60. A man with a higher score may want to do more frequent testing.
“We haven’t solved every single problem with screening,” Dr. Vickers noted. “We need to screen fewer people, screen the right people, and we don’t have to treat every cancer we catch.”
Vickers AJ, Cronin AM, Bjork T, et al.
Prostate specific antigen concentration at age 60 and death or metastasis from prostate cancer: case-control study. BMJ 2010;341.
Prostate specific antigen concentration at age 60 and death or metastasis from prostate cancer: case-control study -- Vickers et al. 341 -- bmj.com
Objective To determine the relation between concentrations of prostate specific antigen at age 60 and subsequent diagnosis of clinically relevant prostate cancer in an unscreened population to evaluate whether screening for prostate cancer and chemoprevention could be stratified by risk.
Design Case-control study with 1:3 matching nested within a highly representative population based cohort study.
Setting General population of Sweden taking part in the Malmo Preventive Project. Cancer registry at the National Board of Health and Welfare.
Participants 1167 men aged 60 who provided blood samples in 1981 and were followed up to age 85. Main outcome measures Metastasis or death from prostate cancer.
Results The rate of screening during the course of the study was low. There were 43 cases of metastasis and 35 deaths from prostate cancer. Concentration of prostate specific antigen at age 60 was associated with prostate cancer metastasis (area under the curve 0.86, 95% confidence interval 0.79 to 0.92; P<0.001) and death from prostate cancer (0.90, 0.84 to 0.96; P<0.001). The greater the number for the area under the curve (values from 0 to 1) the better the test. Although only a minority of the men with concentrations in the top quarter (>2 ng/ml) develop fatal prostate cancer, 90% (78% to 100%) of deaths from prostate cancer occurred in these men. Conversely, men aged 60 with concentrations at the median or lower (≤1 ng/ml) were unlikely to have clinically relevant prostate cancer (0.5% risk of metastasis by age 85 and 0.2% risk of death from prostate cancer).
Conclusions The concentration of prostate specific antigen at age 60 predicts lifetime risk of metastasis and death from prostate cancer. Though men aged 60 with concentrations below the median (</=1 ng/ml) might harbour prostate cancer, it is unlikely to become life threatening. Such men could be exempted from further screening, which should instead focus on men with higher concentrations.
). Perhaps they can just lie to those few and make them feel better.[
Or really what is the reason? I am sure the doc can find an angle to biopsy about 85% of the area without damaging the honeyhole, but he doesn't really know where to look if its on the front. Even if they run some kind of camera, or ultrasound down the uretha, its not going to match up to the "Golden Digit"...
