Abstract 1992P
Background
Recently phenomenon of neurogenesis and axonogenesis has been discovered in prostate cancer (PCa). The relation between cancer and nerves can be specified as perineural invasion (PNI) and nerve density (ND). The role of sympathetic and parasympathetic compounds of the autonomic nervous system differs between tumor type. PNI and increased ND may be an unfavorable prognostic factors in PCa. TMPRSS2-ERG fusion is an early genetic alteration in PCa and regulates important processes in prostate tumorigenesis. The aim of the study was the assessment of the ERG status in relation with chosen parameters of neural microenvironment and characteristics of the tumor.
Methods
73 radical prostatectomy specimens were examined (tumor stage pT1b to pT3b) classified as grade group 1(12), 2(33), 3(13), 4(7), and 5(8). The presence of PNI was assessed. Tissue microarrays were prepared. Immunostaining for ERG and neural markers: PGP 9.5 (panneural) and TH (for sympathetic fibers) was performed with routine protocols. Neural density (ND) was specified as the number of independent PGP 9.5 and TH positive structures- dots/ lines in 10 hot spots tumor areas under 200x (Olympus Bx51 microscope). Structures were counted manually. ERG was examined in a 0-1-2 scale. Statistical analysis was performed with P<0,05 considered as statistically significant.
Results
PNI concerned 76% of cases. The ERG status was positive in 47,95 % of cases, 2+ (21,92%), 1+(26,03%), 0 (52,05%). Among ERG+ cases PNI was present in 31(42,46%) and absent in 4 (5,48%) cases; OR=4,03, 95% CI: 1,17-13,90, p=0,02. ERG+ was extraprostatic extension dependent; OR=3,22; 95% CI: 1,19-8,63, p=0,02, but there was no correlation with Grade group (p=0,1) and age (p=0,61) and ERG in examined group. PGP 9.5 and TH staining showed numerous nerve structures in cancer stroma. The average of ND PGP 9.5 in ERG positive cases was higher than ERG negative (36 vs. 26,6 structures/field); 95% CI: 1,03-17,81, p=0,02. The ND TH was independent from ERG status (p=0,89).
Conclusions
ERG-positive PCa presents higher ND assessed with panneural marker and more frequent PNI than ERG-negative cases. TMPRSS2-ERG fusion affects neural microenvironment in PCa.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Medical University of Gdańsk.
Funding
Has not received any funding.
Disclosure
D.S. Sigorski: Travel/Accommodation/Expenses: Astellas. All other authors have declared no conflicts of interest.