| Abstract | Background and Purpose: Topoisomerase II a (Topo
II a) and Her-2/neu are two important targeted therapeutic
molecules. The immunohistochemical expression of both
of them has not been widely studied in prostatic carcinoma
and benign prostatic hyperplasia (BPH). The aim of this
study was to evaluate the immunohistochemical expression
of Topo II a and Her-2/neu in prostatic carcinoma and
BPH and compare the expression patterns of both genes
in cases of prostatic carcinoma in relation to Gleason
score and hormonal status.
Material and Methods: Paraffin blocks of 30 cases
of prostatic carcinoma (categorized by Gleason score and
hormonal status) and 5 cases of BPH presented to the
Department of Pathology, Faculty of Medicine, Tanta
University during the period from 2005 to 2008 were
retrieved from the files. The immunohistochemical expression
of Topo II a and Her-2/neu antibodies in the
above-mentioned diagnostic categories was investigated
and compared. The percentage of nuclei staining for Topo
II a was semiquantitated; overexpression was defined as
³5% nuclear staining. Her-2/neu immunoreactivity was
scored from 0 to 3+ depending on membrane staining
intensity and pattern.
Results: The expression of Topo II a varied significantly
among the different studied groups (p<0.001). Topo
II a expression increased significantly with increased
Gleason score in prostatic carcinoma (p=0.001). Its expression
in both moderately and poorly differentiated
carcinomas was significantly higher than in BPH (p=0.005
and 0.002 respectively); however the difference between
its expression in well-differentiated carcinoma and in BPH
was statistically insignificant (p=0.171). Her-2/neu expression
was higher in prostatic carcinoma than in BPH,
however the difference did not reach the level of statistical
significance (p=0.084). Also, the increase in its expression
within prostatic carcinoma cases with increased Gleason score was statistically insignificant (p=0.100). There was
a significant correlation between Topo II a and Her-2/neu
expression (p=0.008, r=0.478). Hormone resistant carcinomas
showed higher expression of Topo II a and Her-
2/neu than carcinomas with no hormone treatment, however,
the differences were statistically insignificant
(p=0.594 and 0.667 respectively).
Conclusion: Topo II a expression was significantly
higher in poorly differentiated and moderately differentiated
prostatic carcinoma compared to BPH. There was a
significant increase in Topo II a expression with increased
Gleason score. Her-2/neu expression was higher in prostatic
carcinoma than in BPH, however the difference did not
reach the level of statistical significance and the increase
in its expression with increased Gleason score was also
statistically insignificant. Topo II a and Her-2/neu were
co-expressed significantly. Hormone resistant carcinomas
showed higher expression of both markers, however, the
differences were statistically insignificant. The latter
finding may have important therapeutic implications,
however, further large scale studies are required for
confirmation. |