Tumour grade, proliferation, apoptosis, microvessel density, p53, and bcl-2 in prostate cancers: differences between tumours located in the transition zone and in the peripheral zone.
OBJECTIVE
Transition zone (TZ) carcinomas of the prostate are thought to have less malignant potential than tumours that arise in the peripheral zone (PZ). It is unclear, however, whether this can be put down to anatomical reasons alone, or if there are further differences between tumours of both zones.


METHODS
We examined Gleason scores, proliferation and apoptosis rates, microvessel density (MVD), p53 expression and bcl-2 expression in 76 paraffin-embedded radical prostatectomy specimens, containing 54 tumour foci in the TZ and 58 tumour foci in the PZ, matched for volume. The terminal deoxynucleotidyl transferase mediated dUTP-biotin nick end labelling (TUNEL) method was applied to detect apoptotic cells. Proliferation, MVD, p53, and bcl-2 were investigated by immunohistochemistry.


RESULTS
There were significant differences between TZ tumours and PZ tumours in terms of the median Gleason scores (5 versus 7; P < 0.0001), the proliferation rate (3.2% versus 5.2%; P = 0.0003), and the MVD (68.5 versus 104; P = 0.0002), but the median apoptosis rate was quite similar (0.8% versus 0.9%). The p53 and bcl-2 expression were more frequent in PZ cancers as compared to TZ carcinomas (11% versus 2% and 27% versus 6%, respectively).


CONCLUSIONS
There is evidence for lower Gleason scores as well as lower expression of markers related to tumour growth in TZ carcinomas of the prostate, which might contribute to a less malignant clinical behaviour as compared to PZ cancers.
Erbersdobler
Andreas
A
Institute of Pathology, University of Hamburg, Germany. erbersdo@uke.uni-hamburg.de
Fritz
Henning
H
Schnöger
Silvia
S
Graefen
Markus
M
Hammerer
Peter
P
Huland
Hartwig
H
Henke
R Peter
RP
D000368:Aged; D017209:Apoptosis; D014408:Biomarkers, Tumor / Q000032:analysis*; D002455:Cell Division; D046508:Culture Techniques; D006801:Humans; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D008297:Male; D008833:Microcirculation / Q000502:physiology; D008875:Middle Aged; D009367:Neoplasm Staging; D011336:Probability; D011379:Prognosis; D011467:Prostate / Q000098:blood supply / Q000473:pathology*; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000473:pathology* / Q000601:surgery; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D012680:Sensitivity and Specificity; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
D014408:Biomarkers, Tumor; D019253:Proto-Oncogene Proteins c-bcl-2; D016159:Tumor Suppressor Protein p53