EURURO Vol. 72 No. 6

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received prostatectomy or radiation therapy . Contem-
porary AS programs also incorporate serial prostate biopsies
every 1–5 yr. Prostate biopsies provide information on
grade and tumor volume but are invasive with
increasing infectious complications . Finally, numerous
AS programs have recently begun using MRI, reporting a
high positive predictive value for disease progression
. MRI is more expensive and time consuming than blood
or urinary markers, but less invasive than biopsy. No data
from prospective, randomized trials are published compar-
ing alternative conservative management strategies.
Decision-analytic modeling studies are useful in such
situations with multiple management alternatives with
substantial tradeoffs and no randomized evidence support-
ing one approach over another . The results of our
decision analysis provide novel data demonstrating that the
testing regimen during AS has only a small impact on
estimates of LYs or QALYs. By contrast, tumor features,
treatment-related morbidity, and patient preferences may
have a large impact on the preferred approach to conserva-
tive management, suggesting that patient-shared decision
making with an individualized assessment of tumor
characteristics and patient preferences is important even
once a patient has chosen to defer treatment . Although
there are challenges associated with performing preference
assessment in clinical practice, this is an area of significant
active investigation
Randomized trials comparing surgery versus observation
suggested that certain subgroups have greater benefit from
aggressive treatment (eg, age <65 yr, PSA >10) Our
model suggests that some of these same factors also affect
the preferred approach to conservative management, with
trade-offs between more intensive testing to detect reclas-
sification in time for curative treatment with potential side
effects, versus less intensive testing without curative intent.
These results are consistent with what has been observed
comparing various AS approaches in the literature Fac-
tors that increase the risk of severe, lasting treatment-
related complications also favor a less intensive approach to
conservative management (WW), whereas factors increas-
ing the risk of metastasis with untreated cancer favor a more
intensive approach (AS). Overall, there was limited benefit to
performing additional biopsies after age 75 yr (<10 yr life
expectancy) and already more harm than benefit in the
cohort aged 65 yr, suggesting that a transition to WW
around this time is reasonable.
We also observed that the preferred choice of monitoring
during conservative management was exquisitely sensitive
to time preference. A recent study found that time
discounting was negatively associated with choice of
[(Fig._1)TD$FIG]
Fig. 1 – Schematic diagram of the state-transition Markov model for men undergoing conservative management of prostate cancer showing all the
possible states that men in the model can be in and all the possible transitions between states. At the start, men have been diagnosed with PCa and
have chosen conservative management. Some were classified accurately with Gleason 6 (grade group 1), while others were misclassified and have
undetected higher-grade disease. During each model cycle, individuals can remain on conservative management, undergo treatment for
reclassification (then into a post-treatment state), develop metastases, or die. PCa = prostate cancer; Prog = progression; Tx = treatment. Biopsy,
treatment and post-treatment states are silent during watchful waiting. In the efficacy analysis shown in this paper, patients only undergo treatment
for evidence of reclassification.
E U R O P E A N U R O L O GY 7 2 ( 2 0 17 ) 8 9 9 – 9 0 7 903