Diagnostic significance of stromal changes in biopsies of prostate adenocarcinoma

The diagnostic value of stromal changes in carcinomas, including prostate, is under debate; in terms of limited sample tissue of biopsy, in addition to glandular alterations, the stromal changes could have additional diagnostic value, but the results in clinical settings are controversial. The research aims to evaluate the potential of stromal changes as a supplementary tool to predict the presence of higher grade carcinomas in the prostate using Masson's trichrome and Fanconi anemia complementation group M (FANCM) antibody stainings. 385 biopsies and corresponding radical prostatectomy specimens were analyzed to evaluate the rates of the diversity of ISUP grades. Of 128 upgraded prostatectomy cases, 82 were diagnosed with ISUP Gleason Grade 1 (GG1) in a biopsy. All 82 cancerous samples were stained with Masson's trichrome and FACNM antibody and compared with 82 samples without cancer to see if there was a difference in stromal composition. Additionally, 50 GG1 samples without the upgrade were stained to demonstrate if stromal changes can predict less differentiated carcinomas in the prostate. In FANCM stained samples, the average percentage of positively staining stroma over the total in non-upgraded GG1 biopsies was 36 % (13-59 %, SD = 11); 34 % (9-58, SD = 13) in samples from the upgraded cancerous group, and 44 % (22-69, SD = 11) in samples without cancer. In Masson's trichrome stained samples, with collagen quantified, the percentage in non-upgraded GG1 biopsies was 41 % (20-78 %, SD = 11); 44 % (23-89, SD = 15) in samples from upgraded cancerous group and 37 % (15-57, SD = 9) in samples without cancer. In both FANCM and Masson's trichrome, no statistical significance was found between upgraded and non-upgraded groups (p = 0.84 and p = 0.5, respectively), although some upgrades from GG1 to GG4 showed extreme values. The statistical significance was found in cancerous vs. benign samples with both FANCM (p < 0.01) and Masson's trichrome (p = 0.012). The main limiting factor is a significant overlap in staining intensity between cancerous and cancer-free groups.