Investigation of Neural Microenvironment in Prostate Cancer in Context of Neural Density, Perineural Invasion, and Neuroendocrine Profile of Tumors

Dawid Sigorski; Jacek Gulczyński; Aleksandra Sejda; Wojciech Rogowski; Ewa Iżycka-Świeszewska

doi:10.3389/fonc.2021.710899

Investigation of Neural Microenvironment in Prostate Cancer in Context of Neural Density, Perineural Invasion, and Neuroendocrine Profile of Tumors

Front Oncol. 2021 Jul 1:11:710899. doi: 10.3389/fonc.2021.710899. eCollection 2021.

Authors

Dawid Sigorski^{1

2}, Jacek Gulczyński^{3

4}, Aleksandra Sejda⁵, Wojciech Rogowski^{6

7}, Ewa Iżycka-Świeszewska^{3

4}

Affiliations

¹ Department of Oncology, Collegium Medicum, University of Warmia and Mazury, Olsztyn, Poland.
² Department of Oncology and Immuno-Oncology, Warmian-Masurian Cancer Center of the Ministry of the Interior and Administration Hospital, Olsztyn, Poland.
³ Department of Pathology and Neuropathology, Medical University of Gdańsk, Gdańsk, Poland.
⁴ Department of Pathomorphology, Copernicus Hospital, Gdańsk, Poland.
⁵ Department of Pathomorphology, Collegium Medicum, University of Warmia and Mazury, Olsztyn, Poland.
⁶ Department of Health, Pomeranian University in Słupsk, Słupsk, Poland.
⁷ Department of Oncology, Chemotherapy, Clinical trials, Regional Hospital, Słupsk, Poland.

Abstract

Background: Cancer stroma contains the neural compartment with specific components and action. Neural microenvironment processing includes among others axonogenesis, perineural invasion (PNI), neurosignaling, and tumor cell neural/neuroendocrine differentiation. Growing data suggest that tumor-neural crosstalk plays an important function in prostate cancer (PCa) biology. However, the mechanisms involved in PNI and axonogenesis, as well as their patho-clinical correlations in this tumor are unclear.

Methods: The present study was carried out on FFPE samples of 73 PCa and 15 benign prostate (BP) cases. Immunohistochemistry with neural markers PGP9.5, TH, and NFP was performed on constructed TMAs and selected tissue sections. The analyzed parameters of tumor innervation included small nerve density (ND) measured on pan-neural marker (PGP9.5) and TH s4tained slides, as well assessment of PNI presence and morphology. The qualitative and topographic aspects were studied. In addition, the expression of neuroendocrine marker chromogranin and NPY was assessed with dedicated indexes. The correlations of the above parameters with basic patho-clinical data such as patients' age, tumor stage, grade, angioinvasion, and ERG status were examined.

Results: The study showed that innervation parameters differed between cancer and BP. The neural network in PCa revealed heterogeneity, and ND PGP9.5 in tumor was significantly lower than in its periphery. The density of sympathetic TH-positive fibers and its proportion to all fibers was lower in cancer than in the periphery and BP samples. Perineural invasion was confirmed in 76% of cases, usually multifocally, occurring more commonly in tumors with a higher grade. NPY expression in PCa cells was common with its intensity often rising towards PNI. ERG+ tumors showed higher ND, more frequent PNI, and a higher stage. Moreover, chromogranin-positive cells were more pronounced in PCa with higher NPY expression.

Conclusions: The analysis showed an irregular axonal network in prostate cancer with higher neural density (panneural and adrenergic) in the surroundings and the invasive front. ND and PNI interrelated with NPY expression, neuroendocrine differentiation, and ERG status. The above findings support new evidence for the presence of autocrine and paracrine interactions in prostate cancer neural microenvironment.

Keywords: NPY; nerve density; neural microenvironment; perineural invasion; prostate cancer.