Fall 2011 - Institute of Medical Science - University of Toronto

FEATURE
Pick Your Brain...
A column by Aaron Kucyi
Chronic prostatitis is a disorder that occurs in
5-10% of men and is associated with pain of the
prostate and surrounding areas. Also known as
chronic pelvic pain syndrome (CPPS), the disorder
is unrelated to prostate cancer, and its cause is
uncertain. Most research on CPPS has focused
on factors such as inflammation, endocrine involvement,
and pelvic floor muscle abnormalities.
However, spontaneous pain perception in
CPPS is ultimately a result of brain activity – an
underexplored phenomenon that was recently
investigated for the first time by researchers at
Northwestern University.
In an MRI study of a group of 19 male CPPS patients,
activity in the right anterior insula (a painrelated
brain region) was associated with fluctuations
in the intensity of spontaneous pain over
time. In terms of brain structure, there were no differences
in total volume or volume of pain-related
regions between patients and healthy controls.
However, higher gray matter density in the right
anterior insula was associated with higher overall
pain experienced by a patient. Also, the relationship
between brain gray matter (neuronal cell
bodies) and white matter (axonal tracts) was disrupted
in patients relative to controls. The neural
changes in CPPS are both similar and unique from
other chronic pain disorders. As CPPS is poorly understood
and difficult to treat, this work provides
important insights that can open up new directions
for research on the mechanisms underlying the
disorder, and potentially pain management.
Reference:
Farmer MA, Chanda ML, Parks EL, Baliki MN, Apkarian AV,
Schaeffer AJ (2011) Brain functional and anatomical changes
in chronic prostatitis/chronic pelvic pain syndrome. J Urol
186:117-124.
allow them an opportunity to monitor the
disease through regular follow up appointments.
Curative therapies are recommended
if the preceding criteria advance to indicate
grade progression or volume progression.
Follow up is important. At enrolment, men
have their PSA measured and undergo a digital
rectal exam (DRE). PSA values are drawn
and DREs undertaken every 3 and 6 months,
respectively, for the first two years. A confirmatory
biopsy will also be scheduled within
the first year after diagnosis to ensure that a
more high-risk tumour was not missed. After
the first two years, individuals undergo
PSA measurements every six months and
DREs annually, as well as re-biopsy every two
to three years. Patients will remain on this
schedule of care indefinitely unless there is
tumour grade progression. At this point, radiation
therapy or surgical excision with curative
intent will be scheduled, although this
is necessary only for a minority of patients.
A rapid rise in PSA, particularly a PSA doubling
time faster than 3 years, should necessitate
a repeat biopsy or multiparametric MR
imaging. Importantly, patients that progress
to high-risk disease appear no more likely to
die than patients who were treated radically
at the outset of their diagnosis 2 . Why should
a prostate cancer patient with low-risk disease
opt for active surveillance over radical
treatment? Firstly, prostate cancer is very
common: Roughly 1 in 7 men will be diagnosed
with prostate cancer during their life 1 ,
although many of these men harbour clinically
insignificant disease. Perhaps more surprising
is that upwards of 1 in 2 men will have
previously undetected tumours at death 3 .
Furthermore, prostate cancer is slow growing:
Tumours often grow over the course of
several decades – many do not transform
into aggressive cancers, therefore offering
a long timeframe for surveillance 4 . Finally,
men with localized prostate cancer are more
likely to die of other causes than prostate cancer.
Patients diagnosed with microfocal low
grade cancer based on an elevated PSA managed
with active surveillance are 19 times
more likely to die of other causes than die of
the disease 2 . These facts support the notion
that radical treatment is often unnecessary,
and many with the disease are well suited for
close monitoring of disease progress.
In summary, active surveillance is a prostate
cancer management strategy that allows for
patients with low-risk disease to avoid the
consequences of overtreatment yet feel confident
that they will benefit from curative
treatment if necessary. Active surveillance
serves as a prudent model for individualized,
patient-centred cancer care.
References
1. Klotz L, Zhang L, Lam A, Nam R, Mamedov A,
Loblaw A. Clinical results of long-term follow-up of a
large, active surveillance cohort with localized prostate
cancer. J Clin Oncol 2010;28:126–31
2. Croswell JM, Kramer BS, Crawford ED. Screening
for prostate cancer with PSA testing: current status
and future directions. Oncology (Williston Park). 2011
May;25(6):452-60, 463.
3. Sakr WA, Haas GP, Cassin BF, Pontes JE, Crissman
JD. The frequency of carcinoma and intraepithelial
neoplasia of the prostate in young male patients. J Urol
1993;150:379–85.
4. Soloway, M. S. et al. Careful selection and close
monitoring of low-risk prostate cancer patients on active
surveillance minimizes the need for treatment. Eur.
Urol. 58, 831–835 (2010).
IMS MAGAZINE FALL 2011 PROSTATE CANCER | 22