Page 35 - An Evidence Review of Active Surveillance in Men With Localized Prostate Cancer

age, presence of comorbidities, lower Gleason score, lower tumor stage, lower diagnostic PSA,
lower risk groups, or decreased baseline anxiety. The following patient and clinical variables are
potentially important in increasing the probability that a patient interrupts an observational
management strategy to seek definitive treatments: younger age, higher tumor stage, higher
diagnostic PSA, higher PSA velocity, higher risk groups, or increased anxiety.
As most of these tentative conclusions are drawn from multivariable analyses of large
databases that did not specifically address the factors that affect the offer or acceptance of or
adherence to AS, whether different treatment options were offered to the patients, whether they
accepted those options, and whether they adhered to their initial choices could only be inferred
from whether they received the treatments or not. In addition, retrospective studies could not
provide adequate data for unbiased analyses, because patient characteristics are strongly
associated with initial treatment choice.
No trial provided results from comparisons of AS with RP or RT in men with localized
diseases. One trial reported that men who underwent RP had lower mortality than men on WW;
one trial reported that there was no difference in mortality comparing men having undergone RP
with men in WW. Retrospective studies suggest that men on conservative management had a
higher prostate-cancer-specific mortality than men treated with RP. Men who had RPs had more
urinary complications than men on WW. Retrospective studies also reported that men treated
with RT had lower mortality than men on WW. They also reported higher rates of urinary
strictures in men treated with RT compared with men on WW. Definitive conclusions for men
with low-risk disease on AS or WW versus RP or RT will have to await results from two
ongoing trials: Prostate cancer Intervention Versus Observation Trial (PIVOT: Observation vs.
RP) and Prostate Testing for Cancer and Treatment trial (ProtecT: AS vs. RP or RT).
Although cost calculations using retrospective primary data were performed using different
methods and followup durations in each study, it appears that generally WW is associated with
lower treatment costs compared with active treatment. On the other hand, model-based cost
analyses of AS compared to active treatments suggested that AS costs accumulate over time. In
these models, at 10 and 15 years of followup, AS appeared to be less expensive than active
treatments. However; based on a model with a lifetime horizon, the costs of AS may exceed
those of RP and BT with long term followup, and may be lower than those of IMRT or proton
beam RT.

ES-25