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PATHOLOGY
Risk
of Prostate Cancer on First Re-Biopsy within 1 Year Following a Diagnosis
of High Grade Prostatic Intraepithelial Neoplasia is Related to the Number
of Cores Sampled
Herawi M, Kahane H, Cavallo C, Epstein JI
Department of Pathology, The Johns Hopkins University School of Medicine,
Baltimore, Maryland, USA
J Urol. 2006; 175: 121-4
- Purpose:
We determined the influence of the extent of needle biopsy sampling
on the detection rate of cancer on first biopsy within 1 year following
a diagnosis of HGPIN.
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Materials and Methods: We
identified 791 patients with HGPIN on the initial biopsy who had a followup
biopsy within 1 year of their diagnosis. The mean interval from diagnosis
of HGPIN to re-biopsy was 4.6 months. In the initial biopsy with HGPIN,
323 men had 8 or more cores (median 10, range 8 to 26) and 332 men had
6 core biopsies.
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Results:
In the 6 core initial sampling group, the risk of cancer on re-biopsy
was 20.8% compared to only 13.3% following an initial 8 core or more
sampling (p = 0.011). With 6 core biopsies for both the initial and
re-biopsy the risk of cancer was 14.1% (group 1). With an initial 6
core biopsy and 8 core or more biopsy on followup, the risk of cancer
was 31.9% (group 2). With 8 core or more biopsy sampling for both initial
and repeat biopsies, the risk for cancer was 14.6% (group 3). The differences
between groups 1 and 3 as compared to group 2 were statistically significant
(p = 0.001 and p < 0.0001, respectively).
-
Conclusions:
With relatively poor sampling (6 cores) on the initial biopsy, associated
cancers are missed resulting in only HGPIN on the initial biopsy, and
with relatively poor sampling on re-biopsy there is also a relatively
low risk of finding cancer on re-biopsy (group 1). With poor sampling
on the initial biopsy and better sampling on re-biopsy, some of these
initially missed cancers are detected on re-biopsy yielding a higher
detection of cancer (group 2). Sampling more extensively on the initial
biopsy detects many associated cancers, such that when only HGPIN is
found they often represent isolated HGPIN. Therefore, re-biopsy even
with good sampling does not detect many additional cancers (group 3).
Our study demonstrates that the risk of cancer on biopsy within 1 year
following a diagnosis of HGPIN (13.3%) is not that predictive of cancer
on re-biopsy if good sampling (8 or more cores) is initially performed.
For patients diagnosed with HGPIN on extended initial core sampling,
a repeat biopsy within the first year is unnecessary in the absence
of other clinical indicators of cancer.
- Editorial
Comment
In 2005 were published the recommendations on prognostic factors in
prostate needle biopsies of an International Consultation Organized
by the WHO Collaborating Center for Urologic Tumors (1). The recommendations
included: 1) As the clinical significance or biologic relevance of low-grade
prostatic intraepithelial neoplasia is not known and appears insignificant,
this diagnosis should not be made in needle biopsies; 2) The diagnosis
of high-grade prostatic intraepithelial neoplasia (HGPIN) is predictive
of subsequent cancer detection in 27% to 31% (recent data) and 30% to
60% of patients, respectively; 3) Owing to the lower predictive value
for cancer in recent years, attention has focused on HGPIN parameters
in needle core biopsies that may be more useful in the subsequent detection
of cancer. Whether the extent of involvement of HGPIN is a better predictor
of subsequent prostate cancer is controversial as well as the pattern
of HGPIN (micropapillary, cribriform, etc.).
In the study surveyed, the risk of cancer on biopsy within 1 year following
a diagnosis of HGPIN was 13.3% in cases of an initial 8 core or more
sampling. This percentage is lower than 27% to 31% of other recent studies.
This study emphasizes the trend for a substantially decreasing in subsequent
cancer detection if HGPIN is seen in extended biopsies. The authors
conclude that for patients diagnosed with HGPIN on extended initial
core sampling, a repeat biopsy within the first year is unnecessary
in the absence of other clinical indicators of cancer.
Reference
1. Amin M, Boccon-Gibod L, Egevad L, Epstein JI, Humphrey PA, Mikuz G,
et al.: Prognostic and predictive factors and reporting of prostate carcinoma
in prostate needle biopsy specimens. Scand J Urol Nephrol Suppl. 2005;
216: 20-33.
Dr.
Athanase Billis
Full-Professor of Pathology
State University of Campinas, Unicamp
Campinas, São Paulo, Brazil |