Issue 4 - August 2010 - Pacini Editore

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and molecular tests gave adequate results respectively in the
98,4% and in 95,3%. In particular our method of aliquoting
the aspirated samples into routine smears and the buffer for
DNA extraction did not affects the “informativeness” of the
cytopathological diagnosis. Recently, Xing suggested that,
for prognostic purpose, perhaps all patients with cytologically
diagnosed PTC should be preoperatively tested for BRAF
mutation. In this respect this test provides information that
are additional and non redundant to those provided by a well
taken and correctly interpreted thyroid FNA. Our data showed
that in a routine clinical setting FNA specimens can properly
be handled to provide both morphological and molecular information.
Although a large number of studies have reported
BRAF analysis of thyroid nodules aspirates only recently a
prospective study, on a large of number and with a complete
molecular analysis, was published. However on site-evaluation
was performed only in a minority of cases and the issues
of sample collection was not taken into account 7 . Our study
focusing on the single steps required to aliquot the aspirated
material into routine smears and DNA extraction buffer may
help to implement BRAF testing in the prognostic evaluation
of PTC diagnosed by FNA. Our proposed method ensures
that this test does not interfere with conventional cytology
diagnostic accuracy.
references
1 Baloch ZW, et al. Cytojournal 2008;5:6.
2 Alexander EK, et al. J Clin Endocrinol Metab 2002;87:4924-7.
3 Cohen Y, Xet al. J Natl Cancer Inst 2003;95:625-7.
4 Xing M, et al. J Clin Endocrinol Metab 2005;90:6373-9.
5 Xing M. Endocr Rev 2007;28:742-62.
6 Troncone G, et al. Cytojournal 2008;5:2.
7 Nikiforov YE, et al. J Clin Endocrinol Metab 2009;94:2092-8
Molecular diagnostic of solid tumors: a practical
approach for systematic pathology. urinary
system
D. Segala, M. Brunelli, G. Martignoni
Department of diagnostic pathology, University of Verona, Verona,
Italy
Clinically robust molecular tests are necessary in current
clinical management of urological malignancies in order to
improve the faculties of choosing the right therapy and screening
patients for target therapies.
Several promising biomarkers for diagnosis, prognosis and
target therapy are now under evaluation.
Urothelial carcinoma of the bladder. The five-years survival
rate for localized bladder cancers and distant metastasis are
94% and 6%, respectively. This fact highlights the importance
of detection and appropriate therapeutic intervention at early
stages of disease.
Two forms of noninvasive bladder cancer are well known
to have a distinct histology and clinical behaviour: papillary
urothelial carcinoma rarely invades and metastasized, whereas
flat carcinoma in situ (CIS) is known to have a high rate of
invasion and metastasis.
Molecular evidences of the presence of distinct pathogenesis
for this two phenotype of urothelial carcinoma are now increasing.
Both tyrosine kinase receptor FGFR-3 and H-RAS
oncogene are primarily involved in the pathogenetic pathway
of low-grade papillary urothelial carcinoma 1 . Flat carcinoma
in situ and invasive urothelial carcinoma predominantly involve
tumour suppressor genes p53, p16 and Rb 2-4 . Tumor
angiogenetic factors are also involved the tumor-promoting
5 th triennial congress of the italian society of anatomic Pathology and diagnostic cytoPathology
extracellular environment 5 6 .
Chromosomal aberrations are also described in the pathogenesis
of bladder cancer. Chromosome 9 alterations are established
to be the earliest events in both pathways of urothelial
carcinoma 7 8 . Moreover, gains of chromosome 3p, 7p, 17q,
and 9p21 deletions (p16 locus) are of special interest given
their potential diagnostic value.
The diagnostic process is usually supported by cistoscopy,
while urine cytology is the most widely used non-invasive
test to detect urothelial tumors. However, the letter is limited
by its low sensitivity. Recently the FDA approved a new
technique which seems to show better specificity ranges, the
multitarget multicolor fluorescence in situ hybridization assay
(UroVysion TM ) 9-12 , that is based on frequent numerical
chromosomal alterations detection and it consists of fluorescently
labelled DNA probes to the pericentromeric regions
of chromosome 3 (red), 7 (green), 17 (aqua) and to the locus
9p21 (gold). With the exception of one study 13 , UroVysion TM
appears to enhance the sensitivity of routine cytology analysis
and it can be used in combination with routine cytology in
case with atypical cytology.
Diagnostic applications of UroVysion TM on histology has also
been suggested, such as the distinction of inverted urothelial
papilloma and bladder carcinoma with endophytic growth pattern.
In fact, a study described chromosomal abnormalities in
72% of bladder carcinomas, in contrast to the absence of gains
and deletions in inverted papilloma 14 .
Since an increasing number of data suggests the presence of
the same typical urothelial carcinoma chromosomal aberration
also in rare histologic subtypes 15 16 (e.g. clear cell adenocarcinoma
and small cell carcinoma of the bladder), the possible
use of UroVysion TM could be a valid tool in the diagnosis of
these rare entities.
Adenocarcinoma of the prostate. The challenge in the years
to come will be to introduce new gene-based diagnostic and
prognostic tests in algorithms integrating the other known
clinical and pathological factors to better manage diagnostic
and therapeutic strategies.
In seek of this purpose, in the last decade an extensive list of
molecular biomarkers has been evaluated. One of the most
notable discoveries is presence of recurrent chromosomal rearrangements,
which lead to a fusion of the androgen-responsive
promoter elements of the TMPRSS2 gene (21q22) to one of
the three of the ETS transcription factors family members ERG
(21q22), ETV (7p21) and ETV4 (17q21) 17 . The prognostic role
of these rearrangements remains controversial, but this discovery
has a great implication in terms of providing new markers
for molecular diagnostic and target therapy 18 19 .
A large number of prognostic molecular markers still waits
for additional studies before eventually undergoing clinical
trials. p27 and p53 tumour suppressor genes expression has
been demonstrated to have a correlation with progression after
prostatectomy 20-23 . Furthermore, several recent studies have
established the importance of PTEN/PI3K/mTOR (mammalian
target of rapamycin) in cell growth, proliferation and oncogenesis
of prostate cancer 24-29 . Finally, some papers suggest the potential
usefulness of proliferation index (ki-67) 30 , microvessel
density 31 and nuclear morphometry 32 , while some others lack
to confirm their prognostic validity 23 33 34 .
Gene expression profiling studies using cDNA microarrays
identified three genetic-differentiated subclasses of prostate
tumours 35 . High grade, advanced stage and recurrent tumours
where much more represented among two of the three subtypes,
one of which also included most lymph node metastases.
Another study, using array-based comparative genomic