Features of the spatial organization and qualitative composition of the collagen matrix in prostate cancer

The study examined the features of the spatial organization and qualitative composition of the collagen matrix in prostate cancer (PCa) and the relationship of these parameters with the clinicopathological characteristics of the disease. Morphometric, histochemical (Masson’s trichrome staining, Picrosirius Red staining), and immunohistochemical methods were applied to analyze collagen architecture parameters in tumor tissue samples from 87 patients with stage II–IV PCa. Analysis of the quantitative parameters of the tumor collagen matrix showed that decreased collagen fiber length and width were associated with advanced tumor stages and the presence of metastases in pelvic lymph nodes and/or distant organs. An increase in collagen fiber density and alignment was observed in tumors of patients with metastases and elevated PSA levels. Qualitative assessment demonstrated that collagen fiber maturity (CMI) was lower in patients with metastases, whereas increased CMI values were associated with higher Gleason scores and grade groups. Immunohistochemical findings indicate variability in COL1A1 and COL3A1 expression within the PCa stroma; notably, COL3A1 expression was also detected in tumor cells. Elevated COL1A1 levels were recorded in PCa tissues of patients with T3-category tumors and increased PSA, whereas COL3A1 expression was primarily associated with metastatic status and higher histological grades. Correlation analysis confirmed a strong relationship between quantitative and qualitative parameters of collagen matrix architecture and the clinicopathological features of PCa. The findings suggest that the structural organization and composition of the collagen matrix play an important role in PCa progression and may serve as potential prognostic markers of disease course.