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Clinical question
What is the best treatment for moderately differentiated or
well-differentiated prostate cancer?
Bottom line
Radical prostatectomy is better than watchful waiting for men with
moderately differentiated or well-differentiated prostate cancer, especially
(and perhaps only) in men younger than 65 years. Although these are the best
data on treatment in this group to date, only 5% of the men in this study
had their cancer detected by screening. Whether these data generalize to men
with screening-detected prostate cancer is unclear but will likely be
assumed by most clinicians and their patients.
Reference
Bill-Axelson A, Holmberg L, Ruutu M, et al, for the Scandinavian Prostate
Cancer Group Study No. 4. Radical prostatectomy versus watchful waiting in
early prostate cancer. N Engl J Med 2005; 352: 1977-84.
Study design: Randomized controlled trial (single-blinded)
Setting: Outpatient (specialty)
Synopsis
This is a 3-year follow-up study to one originally reported in 2002. The
researchers randomized men with localized, well-differentiated, or
moderately differentiated prostate cancer according to World Health
Organization grading to either radical prostatectomy or watchful waiting.
Gleason scores were 2 to 4 for 13% of the men, 5 or 6 for 48%, 7 for 23%,
and 8 to 10 for 5%. The Gleason score was unknown for 11% of patients. Only
5% of cancers were detected by screening, although more than 85% had a
prostate-specific antigen (PSA) level higher than 4.0 ng/mL. Allocation was
concealed, outcomes were blindly assessed, and analysis was by intention to
treat. The vast majority of patients, however, stayed in the group to which
they were assigned. The median duration of follow-up was 8.2 years, and
10-year follow-up data were available for 222 patients. The researchers
prespecified several subgroup analyses by age, Gleason score, and PSA.
Overall, results became more favorable for radical prostatectomy with an
increased duration of follow-up. All-cause mortality was lower in the
radical prostatectomy group (27% vs 32%; P = .04; number needed to treat [NNT]=
20), as was disease-specific mortality (9.6% vs 14.9%; P = .01; NNT = 19).
The likelihood of local progression and distant metastases was also lower in
the treated group. Radical prostatectomy was especially beneficial in men
younger than 65 years; there was little difference between watchful waiting
and surgery in patients older than 65. Although there was no association
between the benefit of surgery and the Gleason score, more than 70% had a
Gleason score of 5 to 7. Therefore, there were too few patients with lower
or higher Gleason scores to confidently assess the benefit of surgery in
those groups or in men with screening-detected prostate cancer.
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