C- 03 : Prostate cancer
Physician Variation in Management of Low-Risk Prostate Cancer: A
Population-Based Cohort Study
Karen E. Hoffman, MD, MHSc, MPH; Jiangong Niu, PhD; Yu Shen, PhD; Jing Jiang, PhD; John W.
Davis, MD; Jeri Kim, MD; Deborah A. Kuban, MD; George H. Perkins, MD; Jay B. Shah, MD; Grace
L. Smith, MD, PhD, MPH; Robert J. Volk, PhD; Thomas A. Buchholz, MD; Sharon H. Giordano, MD,
MPH; Benjamin D. Smith, MD
Journal : JAMA Intern Med.
Year : 2014 / Month : September
Volume : 174
Pages : 1450-1459.
doi:10.1001/jamainternmed.2014.3021
ABSTRACT
Importance Up-front treatment of older men with low-risk prostate cancer can cause morbidity
without clear survival benefit; however, most such patients receive treatment instead of observation.
The impact of physicians on the management approach is uncertain.
Objective
To determine the impact of physicians on the management of low-risk prostate cancer with up-front
treatment vs observation.
Design, Setting, and Participants
Retrospective cohort of men 66 years and older with low-risk prostate cancer diagnosed from 2006
through 2009. Patient and tumor characteristics were obtained from the Surveillance, Epidemiology,
and End Results cancer registries. The diagnosing urologist, consulting radiation oncologist, cancerdirected therapy, and comorbid medical conditions were determined from linked Medicare claims.
Physician characteristics were obtained from the American Medical Association Physician
Masterfile. Mixed-effects models were used to evaluate management variation and factors
associated with observation.
Main Outcomes and Measures
No cancer-directed therapy within 12 months of diagnosis (observation).
Results
A total of 2145 urologists diagnosed low-risk prostate cancer in 12 068 men, of whom 80.1%
received treatment and 19.9% were observed. The case-adjusted rate of observation varied widely
across urologists, ranging from 4.5% to 64.2% of patients. The diagnosing urologist accounted for
16.1% of the variation in up-front treatment vs observation, whereas patient and tumor
characteristics accounted for 7.9% of this variation. After adjustment for patient and tumor
characteristics, urologists who treat non–low-risk prostate cancer (adjusted odds ratio [aOR], 0.71
[95% CI, 0.55-0.92]; P = .01) and graduated in earlier decades (P = .004) were less likely to manage
low-risk disease with observation. Treated patients were more likely to undergo prostatectomy
(aOR, 1.71 [95% CI, 1.45-2.01]; P < .001), cryotherapy (aOR, 28.2 [95% CI, 19.5-40.9]; P < .001),
brachytherapy (aOR, 3.41 [95% CI, 2.96-3.93]; P < .001), or external-beam radiotherapy (aOR, 1.31
[95% CI, 1.08-1.58]; P = .005) if their urologist billed for that treatment. Case-adjusted rates of
observation also varied across consulting radiation oncologists, ranging from 2.2% to 46.8% of
patients.
Conclusions and Relevance
Rates of management of low-risk prostate cancer with observation varied widely across urologists
and radiation oncologists. Patients whose diagnosis was made by urologists who treated prostate
cancer were more likely to receive up-front treatment and, when treated, more likely to receive a
treatment that their urologist performed. Public reporting of physicians’ cancer management profiles
would enable informed selection of physicians to diagnose and manage prostate cancer.
COMMENTS
The use of many medical and surgical therapies varies widely between clinicians and geographic
regions.
The treatment of men with early-stage prostate cancer is subject to substantial variation not only in
the use of any local therapy (vs observation), but also in the use of specific treatment modalities.
This concern is particularly salient among men with low-risk prostate cancer, a group for whom the
survival benefits of local therapy are less clear, while the potential adverse effects, including urinary
and sexual dysfunction, may be no less apparent. Because surgery and radiation may represent
overtreatment for some men with low-grade tumors, several clinical guidelines now recommend
initial observation (usually in the form of active surveillance) for patients with low-risk disease.
In a well-designed study based on data from Medicare, and the American Medical Association
Physician MasterFile, the authors reported that among more than 12 000 patients diagnosed with
low-risk prostate cancer from 2006 through 2009, only 20% underwent observation. Moreover,
definitive treatment (mainly radiation therapy) was used by 70% and 55% of men aged 76 to 80
years and older than 80 years, respectively, patients for whom the benefits of treatment are most
uncertain.
The authors also estimated how much variation in the use of initial treatment vs observation was
attributable to the diagnosing urologist rather than to measured patient and tumor characteristics.
They determined that 16% of the treatment variation was attributable to the urologist, while patient
and tumor characteristics accounted for only 8%.
Although smaller in magnitude, similar variation was noted among radiation oncologists. Moreover,
while ownership interest in radiation facilities could not be measured directly, the authors reported
that patients whose diagnosing urologist billed for external beam radiotherapy were more likely to
receive this treatment. The inference is that financial interests may somehow contribute to
inappropriate variation and overtreatment.
To start with, more nuanced assessments of cancer biology (eg, volume of cancer on biopsy),
severity of concurrent medical conditions, and functional status are critical to the evaluation of men
with prostate cancer.
Physician beliefs around the indications, benefits, and likely outcomes of treatment are recognized
as one of the most powerful determinants of treatment variation. Insight into patient preferences is
essential to understanding whether variation is appropriate or unwarranted. In many cases,
nonmalleable preferences lead patients to proceed with definitive local therapy even after careful
and transparent counseling of the relatively low risk of disease progression.
A key priority is to improve shared decision making among men with early-stage prostate cancer.
Using patient decision aids to inform patients and their stakeholders about management options can
help ensure that medical care aligns with patient preferences and values.
Pr. Jacques CHANARD
Professor of Nephrology