Eble JN, Sauter G., Epstein JI, Sesterhenn IA - iarc

many stage T1b cancers.
Stage T2
Most of the pathological prognostic information
obtained relating to clinical stage
T2 disease comes from data obtained
from analysis of radical prostatectomy
specimens.
Pathologic examination of the radical
prostatecomy specimen
The key objectives of evaluating the RP
specimens are to establish tumour
pathologic stage and Gleason score. It is
important to paint the entire external surface
of the prostate with indelible ink
prior to sectioning. In most centers, the
apical and bladder neck margins are
removed and submitted either as shave
margins en face [with any tumour in this
section considered a positive surgical
margin (+SM)], or preferably, these margins
(especially the apical) are removed
as specimens of varying width, sectioned
parallel to the urethra, and submitted
to examine the margins in the perpendicular
plane to the ink. In this
method, any tumour on ink is considered
to be a +SM.
The extent of sampling the radical
prostatectomy specimen varies, only
12% of pathologists responding to a
recent survey indicated that they
processed the entire prostate {705,2283,
2645}. It was reported that a mean of 26
tissue blocks was required to submit the
entire prostate and the lower portion of
the seminal vesicles, {1661}. Cost and
time considerations result in many centers
using variable partial sampling
schemes that may sacrifice sensitivity for
detecting positive surgical margins
(+SM) or extraprostatic extension (EPE)
{2354}.
Histologic grade (Gleason)
Gleason score on the radical prostatectomy
specimen is one of the most powerful
predictors of progression following
surgery. Gleason score on the needle
biopsy also strongly correlates with prognosis
following radiation therapy.
Extraprostatic extension (EPE)
This is defined as invasion of prostate
cancer into adjacent periprostatic tissues.
The prostate gland has no true
capsule although posterolaterally, there
is a layer which is more fibrous than muscular
that serves as a reasonable area to
denote the boundary of the prostate
{143}. At the apex and everywhere anteriorly
in the gland (the latter being the
fibromuscular stroma), there is no clear
demarcation between the prostate and
the surrounding structures. These attributes
make determining EPE for tumours
of primarily apical or anterior distribution
difficult to establish.
EPE is diagnosed based on tumour
extending beyond the outer condensed
smooth muscle of the prostate. When
tumour extends beyond the prostate it
often elicits a desmoplastic stromal reaction,
such that one will not always see
tumour with EPE situated in extra-prostatic
adipose tissue. It has been reported
that determining the extent of EPE as
"focal" (only a few glands outside the
prostate) and "established or non focal"
(anything more than focal) is of prognostic
significance {713,714}. Focal EPE is
often a difficult diagnosis Modifications
to this approach with emphasis on the
"level" of prostate cancer distribution relevant
to benign prostatic acini and within
the fibrous "capsule" where it exists, has
been suggested and claimed to have further
value in classifying patients into
prognostic categories following radical
prostatectomy {2812}. More detailed
analysis has not been uniformly
endorsed {705}.
Seminal vesicle invasion (SVI)
Seminal vesicle invasion is defined as
cancer invading into the muscular coat of
the seminal vesicle {712,1944}. SVI has
been shown in numerous studies to be a
significant prognostic indicator
{393,536,579,2589}. Three mechanisms
by which prostate cancer invades the
seminal vesicles were described by
Ohori et al. as: (I) by extension up the
ejaculatory duct complex; (II) by spread
across the base of the prostate without
other evidence of EPE (IIa) or by invading
the seminal vesicles from the periprostatic
and periseminal vesicle adipose
tissue (Ib); and (III) as an isolated tumour
deposit without continuity with the primary
prostate cancer tumour focus.
While in almost all cases, seminal vesicle
invasion occurs in glands with EPE, the
latter cannot be documented in a minority
of these cases. Many of these patients
had only minimal involvement of the seminal
vesicles, or involve only the portion
of the seminal vesicles that is at least
partially intraprostatic. Patients in this
category were reported to have a
Fig. 3.56 Diagram depicting the pathologic stage
categories of prostate cancer in the radical prostatectomy
specimen:
pT2: Represents an organ confined tumour with no
evidence of extension to inked surgical margins,
extension into extraprostatic tissue or invasion of
the seminal vesicles.
pT2+: Not an officially recognized category that
describes an organ confined tumour with extension
to inked surgical margins, but with no evidence
of extension into extraprostatic tissue or
invasion of the seminal vesicles. [It is important to
emphasize that the status of the surgical margins
while very important to document, is not a component
of the TNM staging system per se as any one
other pT stage categories can be associated with
positive margin]
pT3a: Tumour that have extended beyond the
prostate into the extraprostatic tissue. [It is preferable
to specify whether the amount of tumour outside
the prostate is "focal" or non focal or extensive].
pT3b: Tumour invasion of the muscularis of the
seminal vesicle.
favourable prognosis, similar to otherwise
similar patients without SVI and it is
controversial whether SVI without EPE
should be diagnosed {712}.
Lymph nodes metastases (+LN)
Pelvic lymph node metastases, when
present, are associated with an almost
uniformly poor prognosis in most studies.
Fortunately, however, the frequency of
+LN has decreased considerably over
time to about 1-2% today {393,705}. Most
of this decrease has resulted primarily
from the widespread PSA testing and to
a lesser extent from better ways to select
patients for surgery preoperatively. As a
consequence of this decline in patients
with +LN, some have proposed that
pelvic lymph node dissection is no
longer necessary in appropriately selected
patients {198,256}. The detection of
+LN can be enhanced with special techniques
such as immunohistochemistry or
reverse transcriptase-polymerase chain
reaction (RT-PCR) for PSA or hK2-L
Acinar adenocarcinoma 189