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The Prostate
Cancer Outcomes Study (PCOS) was initiated in 1994 by
researchers at the National Cancer Institute (NCI) to look at
the impact that treatments for primary prostate cancer have on
the quality of life of patients. PCOS is a collaboration with
six cancer registries that are part of NCI's Surveillance,
Epidemiology, and End Results (SEER) Program. (The SEER
Program was established by NCI in 1973 to collect cancer data
on a routine basis from designated population-based cancer
registries in various areas of the country.)
PCOS is the first
systematic evaluation of health-related quality-of-life issues
for prostate cancer patients conducted in diverse healthcare
settings and provides a model for similar large follow-up
studies with other cancers. It is expected that better
knowledge of the effects of treatment will help patients,
families, and clinicians make more informed choices about
treatment alternatives. PCOS will also provide some of the
most detailed data collected to date on the patterns of
prostate cancer care.*
The results of
PCOS will be published in various medical journals over the
next few years. Those already published are listed at the end
of this fact sheet.
Background
Prostate cancer is
the single most common form of non-skin cancer in men in the
United States. In the year 2003, an estimated 220,900 men will
be diagnosed with prostate cancer, and some 28,900 will die of
the disease. Prostate cancer exacts a particularly high toll
on African-American men; mortality rates in African-American
men are more than twice as high as rates in white men.
One of the
problems facing prostate cancer patients is the uncertainty of
many issues surrounding the management of the disease. It is
not known, for instance, if the potential benefits of prostate
cancer screening outweigh the risks, if surgery is better than
radiation, or if treatment is better than no treatment in some
cases.
Decisions about
treatments are not easy to make. One problem is that it is
difficult for a physician to predict whether a tumor will grow
slowly with no health consequences to the patient, or will
grow quickly and become life-threatening. Also, there are no
randomized trials that compare the relative benefits of
treating early stage patients with radiation therapy, radical
prostatectomy (surgical removal of the entire prostate gland
along with nearby tissues), or watchful waiting (following the
patient closely and postponing aggressive therapy unless
symptoms of the disease progress). About 80 percent of men
diagnosed with prostate cancer have early stage disease.
In spite of all of
these uncertainties, it is known that certain treatments --
radiation therapy, radical prostatectomy, or hormonal
therapies -- can have detrimental effects on urinary, bowel,
and sexual functions. By collecting comprehensive data on the
health outcomes of various treatments for prostate cancer, the
PCOS will help patients, their families, and physicians make
decisions about treatment options.
Patient
Population
The Prostate
Cancer Outcomes Study uses an already existing population from
the NCI SEER tumor registry system. About 3,500 men from six
NCI SEER cancer registries including Connecticut, Utah, New
Mexico, and the metropolitan areas of Atlanta, Ga., Los
Angeles, Calif., and Seattle, Wash., are participating in the
study. All of the men were diagnosed with primary invasive
prostate cancer from Oct. 1, 1994, though Oct. 31, 1995; their
tumors were biopsied.
Eighty-eight
percent of the patients were diagnosed with clinically
localized disease; 4 percent had evidence of cancer in other
organs. Forty-two percent of the men were treated with radical
prostatectomy, 24 percent with radiotherapy, 13 percent with
hormonal therapy, and 22 percent were not treated.
One of the unique
features of this study is that the participants represent a
large community-based group of patients from diverse racial
and ethnic backgrounds treated in a broad range of health care
settings. In contrast, most previous studies lacked racial and
ethnic diversity and were limited to a small number of men
treated in large cancer centers or academic institutions.
Data Collection
A survey
questionnaire was sent to patients at six, 12, 24, and 60
months after the initial diagnosis. The survey was designed to
focus on quality-of-life issues -- urinary, sexual, andbowel
dysfunctions -- known to be the most relevant to men with
prostate cancer.
A unique aspect of
the PCOS data collection was the extensive effort made to
obtain information from medical records of the patients not
routinely collected by SEER. These included specific
diagnostic procedures, prostate-specific antigen (PSA) values,
clinical stage and grade of tumor, details of treatments
including specific hormonal therapies, and acute complications
of therapies.
Results/Publications
Using the medical
records and surveys of the prostate cancer patients, the
following PCOS analyses have been published:
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The
majority of men who receive active treatment for
clinically localized prostate cancer are satisfied with
their treatment decision. Following radical prostatectomy
or androgen deprivation therapy (ADT), Hispanic men are
less satisfied than non-Hispanic white men.
Men with
early-stage prostate cancer can choose aggressive
treatment or conservative management. The authors
evaluated 2,365 men with clinically localized prostate
cancer, diagnosed between October 1994 and October 1995,
who were available for 24 months of follow-up. Medical
record review and patient-completed surveys measured
treatment satisfaction and provided demographic,
socioeconomic, and clinical data.
Overall, 59.2
percent of subjects were delighted or very pleased with
their treatment selection. The perception of being cancer
free (66.4 percent), maintaining urinary control (64.2
percent) and bowel control (60.5 percent) and normal
erectile function (65.9 percent), having good general
health (71.3 percent), and preserving social relationships
(68.1 percent) were significantly associated with being
satisfied with treatment choice. Men receiving no active
treatment were less satisfied (50.5 percent) than actively
treated men, and Hispanic men were less satisfied than
non-Hispanic white men after undergoing radical
prostatectomy (50.1 percent vs. 58.0 percent) or androgen
deprivation (29.7 percent vs. 71.8 percent).
The majority
of men were satisfied with their treatment selection for
clinically localized prostate carcinoma. Receiving an
active treatment, believing oneself to be free of cancer,
avoiding treatment complications, and having good overall
health and social support were positively associated with
satisfaction.
Reference:
Hoffman RM, Hunt WC, Gilliland FD, Stephenson RA, Potosky
AL. Patient satisfaction with treatment decisions for
clinically localized prostate carcinoma. Results from the
Prostate Cancer Outcomes Study. Cancer April 1
2003;97(7):1653-62.
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On average,
men treated for prostate cancer can expect the same
general quality of life two years after diagnosis
regardless of their initial choice of treatment. Men who
are more bothered by urination or impotence are more
likely to report worse quality of life. Individual
patients must weigh the unique and significant risks of
urinary, bowel, and sexual dysfunction associated with the
different prostate cancer treatments.
The goal of
this study was to determine the relationship between
primary treatment, urinary dysfunction, sexual
dysfunction, and general health-related quality of life (HRQOL)
in prostate cancer. A baseline survey of men diagnosed
with prostate cancer between 1994 and 1995 was completed
by 2,306 men within six to 12 months of diagnosis. These
men also completed a follow-up HRQOL survey two years
after diagnosis. Statistical analyses were used to
determine whether primary treatment, urinary dysfunction,
and sexual dysfunction were associated with general HRQOL
outcomes approximately two years after diagnosis, as
measured by the Medical Outcomes Study 36-item Short Form
Health Survey.
The authors
found that primary treatment was not associated with
two-year general quality of life outcomes in men with
prostate cancer. Urinary function and bother were
associated with worse general quality of life. Sexual
function and bother were also associated with worse
general quality of life, although the relationship was not
as strong as with urinary dysfunction. This implies that
future research should be directed toward finding ways to
improve treatment-related outcomes or help patients better
cope with their post-treatment urinary or sexual
dysfunction.
Reference:
Penson DF, Feng Z, Kuniyuki A, McClerran D, Albertsen PC,
Deapen D, Gilliland F, Hoffman R, Stephenson RA, Potosky
AL, Stanford JL. General quality of life 2 years following
treatment for prostate cancer: what influences outcomes?
Results from the Prostate Cancer Outcomes Study. J Clin
Oncol 2003;21:1147-54.
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Sexual
function and some aspects of physical well-being are
likely to be affected in the first year following
androgen deprivation therapy.
Many men
diagnosed with clinically localized prostate cancer are
initially treated conservatively, receiving neither
surgery nor radiotherapy for the first year. In this
study, 661 men who had been newly diagnosed with
clinically localized prostate cancer were followed for up
to one year. Eligible men received neither surgery nor
radiotherapy within one year of initial diagnosis. Two
hundred and forty-five study patients received androgen
deprivation therapy (ADT) and the remaining 416 patients
received no therapy.
Among men who
were sexually potent before diagnosis, 80 percent of those
on ADT reported being impotent after one year, compared
with 30 percent of those receiving no treatment. Patients
receiving ADT reported more physical discomfort one year
after diagnosis than did men who had received no therapy.
Patients on ADT also experienced a statistically
significant decline in vitality, but not in physical
function. However, patients receiving ADT were more likely
to be satisfied with their treatment decision than those
receiving no therapy.
ADT is a
commonly used therapy for clinically localized prostate
cancer. The authors conclude that men considering ADT as
an initial treatment should be aware that sexual function
and some aspects of physical well-being are likely to be
affected in the first year following this treatment.
Reference:
Potosky AL, Reeve BB, Clegg LX, Hoffman RM, Stephenson RA,
Albertsen PC, Gilliland FD, Stanford JL. Quality of life
following localized prostate cancer treated initially with
androgen deprivation therapy or no therapy. J Natl Cancer
Inst 2002 Mar 20;94(6):430-7.
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There is
strong agreement between self-report surveys and medical
records, especially for more invasive procedures such as
prostatectomy or radiation.
Medical
records are generally accepted as the most accurate source
of information documenting cancer treatments. However, as
the health care system becomes more decentralized and more
cancer care is delivered in outpatient settings, it is
increasingly difficult and expensive to review records
from the many surgeons and medical/radiation oncologists
who administer cancer therapies in the community setting.
Using
1994-1995 data, the authors compared initial treatment for
prostate cancer self-reported (from a mailed questionnaire
or telephone/in-person interview) by 3,196 U.S. men
participating in the Prostate Cancer Outcomes Study with
information obtained from medical records. Agreement
between self-reports and medical records varied by type of
treatment. Generally, agreement was excellent for more
invasive procedures such as prostatectomy or radiation
(more than 80 percent), with decreasing agreement for
hormone shots and pills (less than 70 percent). These
results can serve as a useful guide to researchers
contemplating the use of surveys as an alternative to
medical record abstraction to ascertain treatment in
studies of patient outcomes.
Reference:
Clegg LX, Potosky AL, Harlan LC, Hankey BF, Hoffman RM,
Stanford JL, Hamilton AS. Comparison of self-reported
initial treatment with medical records: results from the
Prostate Cancer Outcomes Study. Am J Epidemiol
2001;154:582-7.
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Sexual
function is the most adversely affected following
external-beam radiation therapy, with problems
continuing to increase between 12 and 24 months
post-radiation. Bowel function problems increased at six
months but were partially resolved by 24 months.
Earlier
studies have reported adverse effects of radiation therapy
on sexual, bowel, and urinary function. However, most of
these studies were small and conducted in referral centers
or academic institutions. In comparison, this study
examined long-term complications of external-beam
radiation therapy for prostate cancer among a large,
random sample of men with clinically localized prostate
cancer from six population-based cancer registries in the
United States. The study population included 497 white,
Hispanic, and African-American men with localized prostate
cancer who were diagnosed between October 1, 1994, and
October 31, 1995, and treated initially with external-beam
radiotherapy. They were interviewed at regular intervals
and medical records were reviewed.
The study
authors found that sexual function was the most adversely
affected quality-of-life domain, with problems continuing
to increase between 12 and 24 months. A total of 43
percent of men who were potent before diagnosis became
impotent after 24 months, while the urinary function score
at this time was relatively unchanged. Bowel function
problems increased at six months, but were somewhat better
by 24 months.
Despite the
side effects, satisfaction with therapy was high, with
more than two-thirds of the men reporting satisfaction
with their treatment and would make the same decision
again. These results are representative of men in
community practice settings and may be of assistance to
men and to clinicians when making treatment decisions.
Reference:
Hamilton AS, Standford JL, Gilliland FD, et al. Health
outcomes after external-beam radiation therapy for
clinically localized prostate cancer: results from the
Prostate Cancer Outcomes Study. J Clin Oncol
2001;19(9):2517-26.
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Men
diagnosed with prostate cancer should be better informed
of the risks and benefits of all treatment options.
Because of the
lack of results from randomized clinical trials comparing
the efficacy of aggressive therapies with that of more
conservative therapies for clinically localized prostate
cancer, men and their physicians may select treatments
based on other criteria. The authors of this study
examined the association of sociodemographic and clinical
characteristics with four management options: radical
prostatectomy, radiation therapy, hormonal therapy, and
watchful waiting.
Three thousand
seventy-three patients with clinically localized prostate
cancer received the following treatments: radical
prostatectomy (47.6 percent), radiation therapy (23.4
percent), hormonal therapy (10.5 percent), or watchful
waiting (18.5 percent). Men age 75 or older more often
received conservative treatment - hormonal therapy alone
or watchful waiting - than aggressive treatment - radical
prostatectomy or radiation therapy. (Almost 58 percent of
men ages 75 to 79 and 82.1 percent of men age 80 and older
received conservative treatment.) In men younger than 60
years, use of aggressive treatment was similar by
race/ethnicity (85.5 percent for white men, 88.1 percent
for African-American men, and 85.3 percent for Hispanic
men). However, among men 60 years old and older,
African-American men underwent aggressive treatment less
often than did white men or Hispanic men. The association
of nonclinical factors with treatment suggests that, in
the absence of definitive information regarding treatment
effectiveness, men diagnosed with prostate cancer should
be better informed of the risks and benefits of all
treatment options.
Reference:
Harlan LC, Potosky A, Gilliland FD, Hoffman R, Albertsen
PC, Hamilton AS, Eley JW, Stanford JL, Stephenson RA.
Factors associated with initial therapy for clinically
localized prostate cancer: Prostate Cancer Outcomes Study.
J Natl Cancer Inst 2001 Dec 19;93(24):1864-71.
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Traditional
socioeconomic, clinical, and pathologic factors can
explain why Hispanic men are more likely to be diagnosed
with clinically advanced-stage prostate cancer than
non-Hispanic whites. By contrast, these factors do not
fully explain the increased rate for African-American
men.
A group of
3,173 men diagnosed with prostate cancer between October
1, 1994, and October 31, 1995, was analyzed. Medical
record abstracts and self-administered survey
questionnaires were used to obtain information regarding
race/ethnicity, age, marital status, insurance status,
educational level, household income, employment status,
comorbidity, urinary function, prostate-specific antigen
level, tumor grade, and clinical stage.
Clinically
advanced-stage prostate cancers were detected more
frequently in African-American men (12.3 percent) and
Hispanic men (10.5 percent) than in non-Hispanic white men
(6.3 percent). Socioeconomic, clinical, and pathologic
factors each accounted for about 15 percent of the
increased risk. After further statistical analyses
adjusting for these factors, the risk remained
significantly increased for African Americans, but not for
Hispanics - meaning that those factors can explain the
increased risk in Hispanics but not in African Americans.
Reference:
Hoffman RM, Gilliland FD, Eley JW, Harlan LC, Stephenson
RA, Stanford JL, Albertsen PC, Hunt WC, Potosky AL.
Factors associated with racial and ethnic differences in
presenting with advanced stage prostate cancer: results
from The Prostate Cancer Outcomes Study. J Natl Cancer
Inst 2001;93(5):388-95.
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Most
hormone-related health outcomes are similar after
surgical vs. medical hormone therapy. The stage at
diagnosis has little effect on outcome.
This study of
health outcomes included 431 men newly diagnosed with all
stages of prostate cancer who received primary androgen
deprivation (AD) therapy but no other treatments within 12
months of initial diagnosis. Comparisons were
statistically adjusted for patient sociodemographic and
clinical characteristics, timing of therapy, and use of
combination androgen therapy.
More than half
of the patients receiving primary AD therapy had been
initially diagnosed with clinically localized prostate
cancer. Among these patients, almost two-thirds had a high
risk that their prostate cancer would progress. Sexual
function outcomes were similar by treatment group both
before and after the men received AD therapy. Men who
received luteinizing hormone-releasing hormone (LHRH)
therapy reported more breast swelling than did patients
who underwent orchiectomy (surgery to remove one or both
testicles) (24.9 percent vs. 9.7 percent). LHRH patients
reported more physical discomfort and worry because of
cancer or its treatment than did orchiectomy patients.
LHRH patients assessed their overall health as fair or
poor more frequently than did orchiectomy patients (35.4
percent vs. 28.1 percent) and also were less likely to
consider themselves free of prostate cancer after
treatment.
The authors
concluded that most endocrine (hormone) -related health
outcomes are similar after surgical vs. medical primary
hormonal therapy. The stage at diagnosis had little effect
on outcomes. These results provide representative
information comparing surgical and medical AD therapy that
may be used by physicians and patients to inform treatment
decisions.
Reference:
Potosky AL, Knopf K, Clegg LX, Albertsen PC, Stanford JL,
Hamilton AS, Gilliland FD, Eley JW, Stephenson RA, Hoffman
RM. Quality-of-life outcomes after primary androgen
deprivation therapy: results from the Prostate Cancer
Outcomes Study. J Clin Oncol 2001;19:3750-7.
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Men recently
diagnosed with prostate cancer report few
disease-related problems before diagnosis, and a high
percentage of men recall this accurately six months
later.
In this study,
the authors attempted to increase understanding of how
accurate information about baseline health status is when
it is collected six months later.
One hundred
and thirty-three men diagnosed with prostate cancer
completed a questionnaire shortly after diagnosis, asking
about pre-diagnostic urinary, sexual, and bowel function.
They were surveyed again using the same items six months
later and asked to recall their pre-diagnostic function.
Reports of pre-diagnostic function obtained at baseline
and six months were compared. Over 70 percent of the men
reported pre-diagnostic functioning at the highest level
on 12 of 17 survey items. For each of these items, recall
at six months was identical to the baseline survey
response for 69 percent or more of the men.
The study's
data provide no convincing evidence that recall differs by
treatment. Overall, the study shows that there is
reasonably high agreement between baseline and six-month
estimates of pre-diagnostic function. The authors also
found that there was a reasonably high agreement between
measures of change that were noted by a physician as they
were discovered (prospective) vs. measures of change that
were recalled by looking back in time (retrospective) over
six months. These findings establish the basis for the use
of retrospective estimates in the main PCOS study to
assess changes in urinary, bowel, and sexual function.
Reference:
Legler J, Potosky AL, Gilliland FD, Eley JW, Stanford JL.
Validation study of retrospective recall of
disease-targeted function: results from the Prostate
Cancer Outcomes Study. Med Care 2000;38(8):847-57.
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Men with
clinically localized prostate cancer who are treated with
radical prostatectomy are more likely to experience
urinary and sexual dysfunction than those treated with
external beam radiation therapy. Bowel dysfunction, on the
other hand, is more common among men receiving external
radiation therapy.
Of the 1,591
men ages 55 to 74 who were treated for localized prostate
cancer and followed for two years, those receiving radical
prostatectomy (1,156) reported more urinary incontinence
(9.6 percent vs. 3.5 percent), and were more bothered by
incontinence (11.2 percent vs. 2.3 percent) than men
receiving radiotherapy (435). More men treated with
prostatectomy also reported being impotent (79.6 percent
vs. 62.5 percent), and among men ages 55 to 59 years, the
prostatectomy patients were more bothered by their loss of
sexual function than were the radiotherapy patients (59.4
percent vs. 25.3 percent). In general, men in the radical
prostatectomy group recovered some urinary and sexual
function during the second year after treatment, while men
in the radiotherapy group remained the same or became
slightly worse.
Two years
after treatment, men receiving radiotherapy reported more
diarrhea (37.2 percent vs. 20.9 percent) and bowel urgency
(35.7 percent vs. 14.5 percent) than did men receiving
radical prostatectomy. In general, prostatectomy had very
little effect on bowel function while radiotherapy
patients experienced a decline in bowel function within
the first four months of receiving treatment and recovered
some function over the two years.
No clear
difference in emotional and mental health or overall
physical health status was seen between the two groups.
Reference:
Potosky AL, Legler J, Albertsen PC, Stanford JL, Gilliland
FD, Hamilton AS, et al. Health outcomes after radical
prostatectomy or radiotherapy for clinically localized
prostate cancer: Results from the Prostate Cancer Outcomes
Study (PCOS). J Natl Cancer Inst 2000;92:1582-1592.
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Radical
prostatectomy causes significant sexual dysfunction and
some decline in urinary function.
At 18 months
or more after surgery, at least 8.4 percent of the
patients were incontinent (lost urinary control) and at
least 59.9 percent were impotent (unable to achieve an
erection sufficient for sexual intercourse). At 24 months,
8.7 percent of men were bothered by the lack of urinary
control; 41.9 percent reported that sexual function was a
moderate-to-big problem. Nevertheless, most men were
satisfied with their treatment choice.
Reference:
Stanford JL, Ziding F, Hamilton AS, et al. Urinary and
sexual function after radical prostatectomy for clinically
localized prostate cancer. JAMA 2000;283:354-360.
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A small
percentage of newly diagnosed prostate cancer cases show
evidence of metastases with imaging techniques -- bone
scans, computerized tomography (CT), and magnetic
resonance imaging (MRI).
Less than 5
percent of the imaging studies done for newly diagnosed
prostate cancer patients showed evidence of metastases.
Specifically, less than 5 percent of men with PSAs between
four and 20 showed positive bone scans and less than 2
percent of men with Gleason scores of six or less had
positive scans. However, for men with serum PSA levels
greater than 50ng/ml and Gleason scores ranging from eight
to 10, the imaging studies were positive in over 60
percent of the cases.
Reports show
that physicians order bone scans for approximately
two-thirds of all new patients and CT exams for about
one-third of new patients. The low positive yields led the
authors to question the cost-effectiveness of ordering
imaging for the majority of men with newly diagnosed
prostate cancer.
Reference: Albertsen
PC. The positive yield of imaging studies in the
evaluation of men with newly diagnosed prostate cancer: a
population based analysis. J Urology 2000;163:1138-1143.
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Three
factors were found to be the best predictors of the spread
of the disease outside the prostate: PSA levels, Gleason
score, and age.
The authors
were looking for clinical information that could predict
the spread of prostate cancer outside the capsule that
encases the prostate gland (extracapsular extension**) in
men who were diagnosed with localized prostate cancer (by
biopsy) and treated by radical prostatectomy; 1,395 men
participated in this study.
The
researchers found that the strongest predictors of
metastasis were high level of PSA, high Gleason score***,
and age greater than 70. They reported that men older than
70 with PSAs greater than 20ng/ml, and a Gleason score of
eight to 10, had an 85 percent chance of having cancer
outside the prostate gland. In contrast, men younger than
50 with PSAs less than 4ng/ml, and a Gleason score less
than seven, had a 24 percent chance of having cancer
outside the prostate gland. PSA was the strongest single
predictor. Ethnicity and region of the country were not
useful for predicting metastases.
Because only
about half of the men with clinically localized disease
undergoing radical prostatectomy had extracapsular
extension, many patients may be subjected to the risks and
complications of surgery without having a realistic
possibility of cure. They also pointed out that physicians
may need to reconsider the widely held view that Gleason
score is the most important clinical indicator of
prognosis.
Reference: Gilliland
FD, Hoffman RM, Hamilton A, et al. Predicting
extracapsular extension of prostate cancer in men treated
with radical prostatectomy: results from the population
based prostate cancer outcomes study. J Urology 1999;162:1341-1345.
On-Going
Studies
Several ongoing
analyses are examining:
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The effects of
treatments on disease-specific function and quality of
life five years after diagnosis.
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The use of
complementary and alternative therapies among survivors of
prostate cancer.
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The risk of
recurrence and use of secondary therapies for prostate
cancer.
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Treatments
used for sexual dysfunction after therapy for localized
disease.
National Cancer
Insititute (NCI)
* A more detailed
description of PCOS is available in the following publication:
Potosky AL, Harlan LC, Stanford JL, et al. Prostate Cancer
Practice Patterns and Quality of Life: the Prostate Cancer
Outcomes Study. J Natl Cancer Inst 1999;91:1719-1724.
** Extracapsular
extension is defined as stage T3 or T4 tumor, positive
regional lymphnodes, and tumor at the margin of the excised
tumor or metastases.
*** The Gleason
score is a method of grading the degree of differentiation of
a tumor. If a cancer is poorly differentiated (looks like an
immature cell), it is likely to be more aggressive; a well
differentiated cell looks more similar to a normal cell and is
usually less aggressive. The Gleason grade for each reading
can range from one to five, with one being the most well
differentiated and five being the most poorly differentiated.
A pathologist will look at the two most poorly differentiated
parts of the tumor and grade them. The Gleason score is the
sum of the two grades, and so can range from two to 10. The
higher the score, the poorer the prognosis.
For
more information about Bladder Cancer or its treatment, please
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