Collagen III deposition and basement membrane integrity alterations: possible predictive markers in metastatic prostate cancer

Abstract

Purpose Metastasis represents the major cause of deaths in cancer patients, and the tumor surrounding extracellular matrix (ECM) passes through changes in its organization during the evolution of this process. Therefore, the aim of the present study was to quantify the deposition of proteins that constitute the ECM, namely total collagen, collagen I (Col I) and collagen III (Col III) in samples from patients with metastatic (mPCa) and non-metastatic prostate cancer (PCa), in addition of evaluating the basement membrane integrity. Methods Tissue samples from 60 patients were divided into three groups according to parameters ISUP grade, TNM staging and PSA concentration: better prognosis (n = 20), worse prognosis (n = 23) and metastatic (n = 17). To quantify collagen, the Picrosirius Red technique was used with further analysis under a polarization microscope, and to basement membrane analysis the Periodic Acid Schiff (PAS) technique was employed, where the coloring was classified in G1, G2 and G3. Results It was observed that the Col I/ Col III ratio was higher in the metastatic group in relation to better prognosis (p = 0.012) and worse prognosis (p = 0.018) groups. About the basement integrity, it was observed that its constitution in the malignant tumor tissue differed from the adjacent non-tumor tissue (p = 0.000). Also, the worsening in the tumor tissue integrity was positively correlated with worse prognosis parameters (advanced ISUP grade, extraprostatic extension and perineural invasion). Conclusion Our study indicates that the absence of Col III can constitute a marker for potential metastatic tumors. The basement membrane integrity also seems to be an indicator of poor prognosis in malignant prostatic tumors.