In July 2010, a research team led by Jonas Hugosson, professor in
urology at the Sahlgrenska Academy, presented the results of a large
randomised study of screening for prostate cancer in Gothenburg, with a
14-year follow up.
The results were published in the prestigious journal The Lancet
Oncology. The study included 10,000 men (the screening group) aged
50-64 years who were randomly assigned to regular blood samples to
check their level of a prostate cancer marker known as PSA (Prostate-
Specific Antigen) every two years, and 10,000 men who were randomly
assigned not to be screened (the control group).
The study showed that regular PSA-screening nearly halved the mortality
from prostate cancer after 14 years. The screening was, however,
associated with a certain risk of over-diagnosis.
The study is one of five papers in the thesis presented by Sigrid
Carlsson, M.D., Ph.D. The thesis also includes an investigation of the
side-effects that screening caused. Most of the men who were detected
by screening to have early, localised prostate cancer and who were
treated with curative intent underwent surgery (radical prostatectomy).
„We analysed the side effects of surgery based on how these can be
measured relative to the reduced mortality from the disease“, says Sigrid
Carlsson from the Department of Urology at the Sahlgrenska Academy.
The results presented in her thesis show that for each man whose life
was saved by PSA screening, four more men will become impotent or
sexually inactive, while less than one more man will experience problems
with urinary incontinence. These figures are lower than those expected
by the scientists.
„There is a significant risk of affecting the sexual performance. Most men
who undergo surgical treatment for prostate cancer become impotent.
But if this is seen in the light of the benefit of a lower mortality, then
the side-effects do not appear to be as large as sometimes claimed,
particularly if we view the situation from a wider perspective. On the
individual level, however, it is clear that there may be considerable
suffering“, says Sigrid Carlsson.
The thesis reveals also a tendency for men in the screening group who
underwent surgery for prostate cancer to be affected by impotence at a
lower degree than those in the control group who underwent surgery. It
was also shown that few men experienced that PSA sampling and taking
biopsies from the prostate causedparticularly high levels of anxiety.
Furthermore, serious life-threatening complications from the biopsy
procedure or from prostate surgery were very uncommon.
The thesis makes clear the advantages and disadvantages of PSA
screening, but the scientists do not believe that the time is right to
recommend general screening. In addition, the screening study is still
ongoing in Gothenburg.
„We need more studies and a longer follow-up. We also need studies
on cost-effectiveness, in combination with measurements of the men’s
quality of life“, says Sigrid Carlsson.
PROSTATE CANCER
Prostate cancer is the most common form of
cancer among Swedish men – approximately 9,000 men are diagnosed
each year. It is also the most frequent cause of cancer death in Swedish
men, and more than 5% of all men die from this form of cancer, often
after a long and painful period of illness.
The thesis has been successfully defended.
Sigrid Carlsson, M.D., Ph.D.,Department of Urology at Sahlgrenska
Academy,
mobile: +46 70 932 8295,
e-mail: sigrid.carlsson@gmail.com