Why are men in their seventies being PSA screened at twice the rate of men in their fifties, when it is the younger ones who would benefit the most, while many of the older ones really do not need it, researchers wrote in the Journal of Clinical Oncology.

According to information gathered in 2000 and 2005, almost half of all males in their seventies had a PSA screening test during the previous twelve months. PSA screening would benefit men in their fifties much more if a prostate diagnosis was made and treated.

The prostate produces Prostate-specific antigen (PSA) – the epithelial cells in the prostate gland produce PSA (prostate-specific antigen), a protein. PSA helps keep the semen in its liquid state. Some of the PSA gets into the bloodstream. We can measure a man’s PSA levels with a blood test. If his levels of PSA are high, it could be an indication of either prostate cancer or some kind of prostate condition.

The authors were even more surprised to find that males aged at least 85 years are being screened at the same rate as fifty-year-old men.

Prostate cancer advances very slowly. Most men who develop the disease in their seventies will die from something else before it ever became a problem big enough to require medical intervention.

The researchers from the University of Chicago explained that their findings confirm a worrying trend of over-screening for Prostate-specific antigen, and the subsequent pointless treatments for older patients. Elderly patients who are treated for prostate problems have a much higher risk of urinary incontinence, bowel dysfunction and erectile dysfunction.

Senior author Scott Eggener, MD, said:

“Our findings show a high rate of elderly and sometimes ill men being inappropriately screened for prostate cancer. We’re concerned these screenings may prompt cancer treatment among elderly men who ultimately have a very low likelihood of benefitting the patient and paradoxically can cause more harm than good. We were also surprised to find that nearly three-quarters of men in their fifties were not screened within the past year. These results emphasize the need for greater physician interaction and conversations about the merits and limitations of prostate cancer screening for men of all ages.”

The percentage of patients whose prostate cancer metastasizes (spreads beyond the prostate) has dropped significantly over the last few years – this decline has occurred while PSA screening rates have risen. However, concern about PSA screening use continues.

When males should be considered for PSA screening has been unclear. Nobody seems to agree when this type of screening should cease. In fact, studies that attempted to determine whether PSA screening had any impact on prostate cancer mortality produced conflicting evidence.

The American Cancer Society advises males who expect to still be alive in ten years’ time to discuss the risks and benefits of PSA screening with their doctor. Those with an average prostate cancer risk should talk to their doctors when they are fifty, while those with a higher risk (close relative with the disease) should do so when they are 45.

Dr. Eggener and team gathered data from the National Health Interview Survey for the years 2000 and 2005. Apart from examining data on disease risk factors, such as BMI (body mass index), underlying medical conditions, age, and smoking, they also worked out the estimated five-year life expectancy of each male aged 40+ who had undergone a PSA screening.

They divided the men into two main groups, males aged at least 70 and males aged 40 to 69 (controls). The older men were divided into five groups – ages 70-74, 75-79, 80-84 and 85+. There were nearly 12,000 men aged 40 to 69.

The following PSA screening rates were revealed:

  • Overall within past year, males aged 40+ – 27% in 2000, and 26% in 2005.
  • Ages 40 to 44 – 7.5%
  • Ages 50-54 – 24%
  • Ages 70-74 – 45.5% (the highest rate)
  • Age 85+ – 24.6%

Among those aged 70+, screening rates were higher for men with a life-expectancy of more than five years. 47.3% of males whose chances of dying within five years were “unlikely”(15% or less) were screened, compared to 39.2% with an “intermediate” chance and 30.7% with the highest chance.

Elder males tend to visit their doctor more often because they generally have more health problems, this could explain their high PSA screening rates, while younger men see their physicians less frequently, Eggener wrote as a possible explanation.

The authors say that doctors should be more discriminating about who should be recommended for PSA screening, favoring more those patients who are expected to live longer.

“Population-Based Patterns and Predictors of Prostate-Specific Antigen Screening Among Older Men in the United States”
Michael W. Drazer, Dezheng Huo, Mara A. Schonberg, Aria Razmaria and Scott E. Eggener
Journal of Clinical Oncology
doi: 10.1200/JCO.2010.31.9004 JCO March 28, 2011 JCO.2010.31.9004

Written by Christian Nordqvist