308 320
1.
Introduction
Health outcomes for individual men with prostate cancer
vary widely and may be influenced by a variety of factors
such as race/ethnicity. It is well established, for example,
that African-American (AA) patients with prostate cancer
exhibit more advanced disease at younger ages and are
more likely to die of their disease compared to white men
[1,2] .While racial variation in oncologic outcomes after
prostate cancer treatment is well studied
[3–6], data on how
patient-reported changes in urinary, sexual, and bowel
function vary after treatment remain sparse
[7] .Data from the Prostate Cancer Outcomes Study (PCOS)
have previously demonstrated that AA men reported better
urinary outcomes compared to white man after radical
prostatectomy
[8]. However, prostate cancer treatment
modalities have undergone substantial technological
advances since the inception of PCOS in 1994. Furthermore,
the PCOS study did not include patients who underwent
active surveillance (AS), which limited the ability to
estimate the effects of treatment and, by extension, to
formally test the race-treatment interaction. Thus, a
contemporary understanding of how race/ethnicity influ-
ences the effects of modern management strategies,
including AS, on functional outcomes is needed.
In this context, we tested the hypothesis that post-
treatment functional outcomes at 12 mo vary across racial/
ethnic groups in a contemporary, prospective, population-
based prostate cancer inception cohort. On the basis of the
previous PCOS study, we hypothesized that AA men would
report better functional outcomes at 1 yr after treatment.
Characterizing the impact of race/ethnicity on treatment-
related functional outcomes is actionable for all racial/
ethnic communities, allowing patients, providers, and other
stakeholders to make data-driven treatment decisions.
2.
Patients and methods
2.1.
Study population
The Comparative Effectiveness Analysis of Surgery and Radiation
(CEASAR) study is a prospective, longitudinal, population-based
observational cohort designed to measure the effectiveness and harms
of contemporary management strategies for men diagnosed with
localized prostate cancer (NCT0136286). Patients were accrued from
five Surveillance Epidemiology, and End Results (SEER) registry
catchment areas (Louisiana, New Jersey, Utah, Atlanta, and Los Angeles).
This data set is augmented with a sample of men enrolled in Cancer of
the Prostate Strategic Urologic Research Endeavor (CaPSURE)
[9] .A total
of 3708 participants were enrolled in CEASAR between 2011 and 2012
(Supplementary Fig. 1). Eligible men were aged 80 yr with clinical stage
cT1 or cT2 disease, prostate-specific antigen (PSA)
<
50 ng/dl, and
diagnosis within 6 mo of enrollment. Race/ethnicity was classified as
non-Hispanic white (white), non-Hispanic AA (AA), and Hispanic,
according to patient-reported data or SEER registry data if patient-
reported data were missing (Supplementary Fig. 1). All other races/
ethnicities were excluded owing to low sample sizes. The CEASAR
methodology, which includes power and sample size calculations, has
previously been described
[10]. The coordinating site at Vanderbilt, each
of the SEER sites, and CaPSURE obtained approval from the relevant local
institutional review board.
2.2.
Survey instruments and medical chart abstraction
Patient-reported disease-specific function was captured using the 26-
item Expanded Prostate Index Composite (EPIC) questionnaire. EPIC is a
validated survey instrument that evaluates function and bother for
urinary, sexual, bowel, and hormone domains as continuous measures
on a scale of 0–100, with higher scores indicating better function
[11]. To
assist in the determination of clinically relevant changes in EPIC domain
scores, we used previously published and validated domain score
thresholds (Supplementary Table 1)
[12]. Participants were also asked to
complete the Total Illness Burden Index for Prostate Cancer (TIBI-CaP), a
validated patient-reported 84-item comorbidity assessment of 11 health
domains modified for patients with prostate cancer
[13,14]. CEASAR also
captured patient-reported race, income, age, educational attainment,
marital status, employment/retirement status, insurance coverage,
general health and function, physical function, social support, emotional
health, cancer-related anxiety, and depression using the Center for
Epidemiologic Studies Depression Scale (CES-D).
Tumor characteristics, treatment selection, PSA levels, and treatment
date were obtained via medical record abstraction. For patients without
chart information, questionnaires and SEER registry data were used to
determine the treatment received. AS was defined as a lack of any
curative intent treatment (RP, radiation therapy, and cryoablation) or
androgen deprivation therapy at the time of the 1-yr functional status
assessment. Patients who underwent both RP and external-beam
radiation therapy (EBRT) were categorized on the basis of primary
treatment. Patients who received primary androgen deprivation therapy
or cryoablation were excluded.
2.3.
Statistical analysis
Patient baseline demographic and clinical characteristics were com-
pared across racial/ethnic groups using Kruskal-Wallis and
x
2
tests. To
characterize typical changes in patient-reported function over time
within each treatment group among each racial/ethnic group, we fitted a
longitudinal regression model for each EPIC domain score, which
Conclusion:
While these data demonstrate that incontinence at 1 yr after RP may be worse
for African-American compared to white men, the difference appears to be modest overall.
Treatment selection and baseline function explain a much greater proportion of the
variation in function after treatment.
Patient summary:
We observed that the effect of treatment for prostate cancer on patient-
reported function did not vary dramatically by race/ethnicity. Compared to white men,
African-American men experienced a somewhat more pronounced decline in urinary
continence after radical prostatectomy, but the corresponding changes in bother scores
were not significantly different between the two groups.
#
2016 European Association of Urology. Published by Elsevier B.V. All rights reserved.
E U R O P E A N U R O L O G Y 7 2 ( 2 0 1 7 ) 3 0 7 – 3 1 4
308