Page 31 - An Evidence Review of Active Surveillance in Men With Localized Prostate Cancer

Observational Management Strategies Versus Combined Active
Treatments or Combined Radiation Treatment Modalities

One study reported that active treatments (RP, RT, and BT considered together) resulted in
lower all-cause and prostate-cancer-specific mortality rates compared to WW. Morbidity of
primary treatment was reported by only one study, which found that a group of patients receiving
EBRT and BT (combination therapy) had a higher rate of receiving treatments for urethral
stricture compared to a group managed using observational management strategies.

Costs

Short- and long-term costs appear to be higher for active treatment strategies (RP or RT)
compared to WW; however, evidence originated from small studies (or studies where the
subgroup of patients receiving observational management was small) using heterogeneous
measurement methods. We did not identify any primary study comparing actual costs of AS
versus active treatment strategies; economic modeling using U.S. prices suggested that within 10
to 15 years of diagnosis AS may be less costly compared to active treatments; a study using a
lifetime horizon indicated that AS may be associated with higher costs compared to RP and BT,
but lower costs compared to intensity modulated RT (IMRT) and proton beam RT. We note that
model based costs are sensitive to the model assumptions and choice of inputs.

Key Question 5. What are the research needs regarding active surveillance
(or watchful waiting) in localized prostate cancer?
The evidence directly addressing the four principal Key Questions is largely incomplete.
There is not yet consistency among clinicians or researchers as to the definitions of AS or WW,
the standard protocols for the interventions, or how to manage patients whose cancers show signs
of progression. There are also many gaps in the evidence regarding the numerous specific factors
and subgroups of interest to the conference.
This review implicitly assumes that it is possible to identify men who are at sufficiently low
risk of progression of their prostate cancer that AS can be a safe and appropriate option for them.
However, additional basic and clinical research is needed to more accurately classify or predict
those men whose diseases are indeed at a low risk of progression. These are the men that
presumably would be most appropriate to consider offering AS.

Key Question 1—Patient Population and Natural History Changes
in the Last 30 Years

Better understanding of time trends can be gained by improving the data collected and
expanding the scope of major U.S. databases. In particular, stage and grade information are often
incomplete, requiring researchers to create broad categories that place major limitations on
analyses. The SEER database often appears inadequate for analyses on races other than blacks
and whites; this may require adding new registries to SEER that better represent other races.
A misclassification bias is likely in the analyses of SEER using the “best available
information” on staging information, because the “best available staging information” depends
on the treatment the patients receive. Patients having surgery are staged more accurately than
those with clinical or imaging staging alone. This bias could be reduced if the SEER database
maintained the staging information available prior to surgery.

ES-21