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

Abstract

BackgroundCancer 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.MethodsThe 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.ResultsThe 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.ConclusionsThe 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.

Perineural invasion detected in prostate biopsy is a predictor of positive surgical margin of radical prostatectomy specimen: A meta‐analysis

“…However, few studies have focussed on whether there is an association between biopsy PNI and PSM. Positive resection after radical prostate cancer affects the survival and prognosis of patients and has paid attention to the majority of urosurgeons (Sigorski et al, 2021). At present, some researchers believe that tumour stage and pathological characteristics are related to positive margin after radical prostate cancer.…”

“…However, few studies have focussed on whether there is an association between biopsy PNI and PSM. Positive resection after radical prostate cancer affects the survival and prognosis of patients and has paid attention to the majority of urosurgeons (Sigorski et al, 2021). At present, some researchers believe that tumour stage and pathological character- Gleason pattern 4 (poorly formed, fused glands, glomerulation, and cribriform types) prostate cancer according to the ISUP 2014 modified Gleason system, and Flammia et al (Flammia et al, 2020) found that cribriform pattern was significantly and inversely correlated with PNI but not with other pathological parameters.…”

The Role of Nerve Fibers in the Tumor Immune Microenvironment of Solid Tumors

“…[133] In cancer research this biomarker have shown to be useful to visualize PNI and quantitate neural structures in primary melanoma and prostate cancer (Figure 3). [134,135]…”

“…This biomarker has being used as a marker of neural and neuroectodermal tumors, to study nerve regeneration in skin samples with herpes virus infection, and to study PNI and nerve density in pancreatic and prostate cancer. [135,[137][138][139]…”

Sympathetic nervous signaling dictates prostate cancer progression

“…Our group found that PCa innervation was higher on the proximal cancer surroundings than within PCa. Moreover, sympathetic ND was lower in PCa than in non-neoplastic prostate [ 5 ].…”