Topics:

Comparing Radical Prostatectomy and Brachytherapy for Localized Prostate Cancer

Comparing Radical Prostatectomy and Brachytherapy for Localized Prostate Cancer

ABSTRACT: Radical prostatectomy and ultrasound-guided transperineal brachytherapy are both commonly used for the treatment of localized prostate cancer. No randomized trials are available to compare these modalities. Therefore, the physician must rely on institutional reports of results to determine which therapy is most effective. While some investigators have concluded that both therapies are effective, others have concluded that radical prostatectomy should remain the gold standard for the treatment of this disease. This article reviews the major series available for both treatments and discusses the major controversies involved in making these comparisons. The data indicate that for lowrisk disease, both treatments are effective, controlling disease in over 80% of the cases, with no evidence to support the use of one treatment over the other. Similarly, for intermediate-risk disease, the conclusion that one treatment is superior to the other cannot be drawn. Brachytherapy should be performed in conjunction with external-beam radiation therapy in this group of patients. For patients with high-risk disease, neither treatment consistently achieves biochemical control rates above 50%. Although radical prostatectomy and/or brachytherapy may play a role in the care of high-risk patients in the future, external-beam radiation therapy in combination with androgen deprivation has the best track record to date.

Radical prostatectomy and
brachytherapy are two commonly
employed methods of
treating localized prostate cancer. Due
to a lack of randomized trials, the
selection of optimal treatment for
these patients remains controversial.
A wealth of single-institution data is
available, but comparisons are difficult
because of differences in patient
selection and outcome end points. This
has resulted in a frustrating situation
for patients and physicians alike.

A number of articles have attempted
to interpret these data, and two
different conclusions have emerged.
Several authors have concluded that
the available evidence indicates both
treatments achieve approximately
equal results and should be offered to
patients with low-risk disease.[1,2]
Other physicians have concluded that
in the absence of randomized trials,
radical prostatectomy should be considered
superior to brachytherapy and
remain the standard of care.[3,4] The
primary reasons cited by these authors
for continuing to regard radical
prostatectomy as superior to brachytherapy
are listed in Table 1.[3-7] In
this review, we will address the latest results of treatment with each modality
and attempt to draw conclusions
regarding their relative merits.

Results of TreatmentSelection of Series
A Pubmed search was utilized in
an attempt to identify all available
series reporting results for transrectal
ultrasound (TRUS)-guided interstitial
low-dose-rate ("seed") brachytherapy
and radical prostatectomy in the
prostate-specific antigen (PSA) era.
Updates published in abstract form
were used when available. For the
sake of comparison, only series that
reported PSA-based outcomes were
considered. Series were selected for
analysis if they included data for at
least 100 total patients in order to
ensure adequate experience with the
procedure.

Authors generally agree that an
accurate comparison of treatment
results can only be achieved if the
patients compared have similar prognostic
factors.[1,3,8] Therefore, series
are presented here only if they reported
results according to standard pretreatment
prognostic factors. The
definitions of risk groups used are
shown in Table 2.

Finally, the importance of adequate
length of follow-up has been demonstrated.[
3,9,10] Therefore, only series
with a median follow-up greater than
3 years are presented. We have attempted
to include the latest update
of each series. In the case of groups
that have published results numerous
times, we have used their latest report
that segregates the patients based on
prognostic factors.

Biochemical Disease-Free Survival
in Brachytherapy Series

Tables 3, 4, and 5 list the results
of available brachytherapy series
for patients with low-, intermediate-,
and high-risk disease, respectively.[
1,2,11-22] Reports by Merrick,[
23,24] Singh,[25] and Blank[26]
are not included because they had either
fewer than 100 patients or less
than 3 years median follow-up. Results
published by Koutrouvelis are
not shown because the implants were
performed via a nonstandard technique.[
27] The results of all of the
above series are consistent with, or
superior to, the results presented in
these tables. Finally, the 32-patient
series from Dr. Holm[28]-the first
transperineal implants ever reported,
last published in 1991-which reported
poorer results, was also excluded.

The majority of the series did not
include any patients who underwent
hormonal manipulation in order to rule
out a possible confounding effect.
Zelefsky et al[11] did include 13% of
patients who underwent androgen
deprivation for a mean duration of
2 months. Patients in the Dattoli,[22]
Lederman,[12] and Kollmeier[13] papers
received hormonal ablation in 30%,
16%, and 60% of the cases, respectively.
D'Amico[29] reported patients who
received androgen deprivation separately,
and they are not shown here. In all
cases, hormonal ablation was of short
duration (3 to 6 months).

Of note, the series from Ragde et
al[14] clearly presents the worst published
results for low-risk patients
treated with brachytherapy. These
were among the first transperineal implants
performed in the United States
(treated from 1987 to 1989), thus representing
the learning curve for this
group, as well as a "discovery curve"
for this procedure, during which time
important refinements in technique
and dosimetry were made. Improvement
in technique, and therefore in
results, should be expected with increasing
experience, and this is demonstrated
in a paper by Grimm et
al.[15] These investigators compared
their data from 1986 to 1987 with
their data from 1988 to 1989, and
demonstrated an improvement in
long-term biochemical no evidence
of disease (bNED) rate from 66% in
the 1986 to 1987 cohort to 87% in the
1988 to 1989 cohort, despite very similar
patient characteristics.

Once each table was completed, a
weighted average of bNED rates for
each prognostic group was calculated
using data from all of the included
series. The percentage bNED at
5 years in each series was multiplied
by the number of patients in that study,
and these results were added together
and then divided by the total number
of patients in the risk group. The data
from Sylvester et al[16] were not used
in these calculations, as the number
of patients in each risk group was not
available.

Biochemical Disease-Free Survival
in Radical Prostatectomy Series

Tables 6, 7, and 8 present the available
data from major series of radical
prostatectomy for patients with low-,
intermediate-, and high-risk features.[
1,2,4,17,30-34] The series from
the University of California, Los Angeles,[
35] is not presented because it
did not stratify results by pretreatment
prognostic factors. Barry et
al[36] did not report biochemical failure
as an end point.

Because several of these series do
not report results stratified by risk
group, but rather, by individual prognostic
factors, the data for those series
are presented for patients who had features
characteristic of that group; ie,
patients with a Gleason score of 7 are
presented in the intermediate-risk table.
It should be noted that this may
have a slight negative effect on the
outcome of patients in the low-risk table,
because some of the subset of patients
who had a PSA < 10 ng/mL
would be expected to have a Gleason
score of 7 or higher, and vice versa.
Data for patients stratified according to
their multifactor risk group is presented
where available.

The results from the University of
Pennsylvania,[1] Baylor,[30] Cleveland
Clinic,[32] William Beaumont
Hospital,[30] and Urology Health
Center[2] are derived from data published
in papers that compared radical
prostatectomy to radiation therapy.
The Johns Hopkins group has published
bNED rates for 5 and 10
years[31]; both are reported here, the
5-year rate to allow comparison to
other series, and the 10-year rate to
show long-term results. Because many
of the surgical series do not provide
the number of patients in each prognostic
group, a useful weighted average
could not be calculated.

Pages

 
Loading comments...
Please Wait 20 seconds or click here to close