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PATHOLOGY
Prognostic
and predictive factors and reporting of prostate carcinoma in prostate
needle biopsy specimens
Amin M, Boccon-Gibod L, Egevad L, Epstein JI, Humphrey PA, Mikuz G, Newling
D, Nilsson S, Sakr W, Srigley JR, Wheeler TM, Montironi R
Department of Pathology and Laboratory Medicine, Emory University School
of Medicine, Atlanta, Georgia, USA
Scand J Urol Nephrol Suppl. 2005; 216: 20-33
- The information
provided in the surgical pathology report of a prostate needle biopsy
of carcinoma has become critical in the subsequent management and prognostication
of the cancer. The surgical pathology report should thus be comprehensive
and yet succinct in providing relevant information consistently to urologists,
radiation oncologists and oncologists and, thereby, to the patient.
This paper reflects the current recommendations of the 2004 World Health
Organization-sponsored International Consultation, which was co-sponsored
by the College of American Pathologists. It builds on the existing work
of several organizations, including the College of American Pathologists,
the Association of Directors of Anatomic and Surgical Pathologists,
the Royal Society of Pathologists, the European Society of Urologic
Pathology and the European Randomized Study of Screening for Prostate
Cancer.
- Editorial
Comment
This consensus meeting was held in Stockholm in 2004 and sponsored by
the World Health Organization. I will emphasize some topics of interest
for the urologist.
1. Histopathologic type: greater than 99% of all carcinomas are acinar.
The remain types include urothelial, ductal (endometrioid), mucinous,
signet ring cell, adenosquamous, small cell carcinoma and sarcomatoid
carcinoma. Although uncommon, the aggregate data on these variants suggest
that they may have diagnostic, prognostic or therapeutic importance.
Urothelial carcinoma is not hormone dependent. Small cell carcinoma
(with or without neuroendocrine differentiation) is usually associated
with widespread, often concurrent, metastasis (frequently to unusual
locations) and rapid acceleration of clinical course. Sarcomatoid carcinoma
(carcinosarcoma) of the prostate, like small cell carcinoma, has an
extremely poor prognosis with a median survival of 3 years.
2. Gleason score: it predicts findings in radical prostatectomy (pathologic
stage), biochemical progression, local recurrences, and lymph node or
distant metastasis. The most significant recommendation is to separately
report the Gleason score for each recognizable core irrespective of
whether the cores are individually submitted (in individual container
signifying specific anatomic location ), or submitted together. Another
important change is the recognition and reporting of the tertiary pattern
of higher grade in needle biopsies. A case with primary pattern 3, secondary
pattern 4, and tertiary pattern 5 should be assigned a Gleason score
3 + 5 = 8.
3. Extent of involvement of needle core: there is lack of consensus
in the literature and, hence, to some extent in clinical practice as
to the best method of reporting the extent of tumor involvement. It
is recommended that the report should provide the number of involved
cores, the percentage estimate of involvement of each of the cores derived
by visual estimation and the linear length in increments of 0.5 mm.
4. Local invasion: the prostate has not a true fibrous capsule. Terms
such as “capsular invasion” or “capsular penetration”
should not be used. The proper term is extraprostatic extension. Only
exceptionally rarely is fat present within the normal prostate. Hence,
tumor in adipose tissue in a needle biopsy specimen can safely be interpreted
as extraprostatic extension.
5. Perineural invasion: although perineural invasion in needle biopsy
specimens is not an independent predictor of prognosis when Gleason
score, serum PSA and extent of cancer are factored in, some studies
indicate that its presence correlates with extraprostatic extension.
The data are conflicting. Clinicians should be aware that all cases
of perineural invasion on needle biopsy would not necessarily have extraprostatic
extension.
6. Reporting of atypical foci suspicious but not diagnostic of malignancy:
atypical small acinar proliferation (ASAP) is not a diagnostic entity
and is not synonymous with high-grade prostatic intraepithelial neoplasia
(HGPIN). It represents descriptive diagnostic terminology in which there
is architectural and/or cytologic atypia that does not reach an individual
pathologists’ threshold required for the diagnosis of cancer.
The term ASAP may be confusing for the urologist. The committee members
recommended designating atypical biopsies as either suspicious or highly
suspicious for cancer. These patients should have a close clinical follow-up
and re-biopsied.
Dr.
Athanase Billis
Full-Professor of Pathology
State University of Campinas, Unicamp
Campinas, São Paulo, Brazil |