Intraductal carcinoma of the prostate (IDC-P) is an aggressive subtype of prostate cancer characterized by the growth of tumor cells within the prostate ducts. It is often found alongside invasive carcinoma and is associated with poor prognosis. Understanding the molecular mechanisms driving IDC-P is crucial for improved diagnosis, prognosis, and treatment strategies. This review summarizes the molecular characteristics of IDC-P and their prognostic indications, comparing them to conventional prostate acinar adenocarcinoma, to gain insights into its unique behavior and identify potential therapeutic targets.

BACKGROUND: Recently, it has been shown that exosomal biomarkers and DNA mismatch repair proteins (MMR) could play an important role in cancer risk stratification and prognosis assessment. The gold standard for prostate carcinoma (PCa) diagnosis is biopsy and histopathological examination. Thus, the complex evaluation of exosomal and MMR proteins could be beneficial for prostate cancer risk stratification and diagnostics. The aim of the current study was to evaluate and compare the expression of exosomal proteins CD9 and CD63 and MMR proteins in the tissue of patients with prostate benign hyperplasia (BPH) and PCa.
METHODS: The study was retrospective. Altogether, 92 patients with PCa and 20 patients with BPH (control group) were enrolled in the study. Exosomal and MMR protein expression was analyzed by immunohistochemistry (IHC). The follow-up for each PCa patient in our study lasted till disease progression and/or a maximum of 5 years.
RESULTS: Low-grade PCa was observed in 56 patients and high-grade PCa in 36 patients. CD63 expression was significantly higher in patients with high-grade PCa compared to those with low-grade PCa. CD9 expression was significantly downregulated in PCa patients compared to the control group. MMR protein expression deficiency was observed in 10 PCa patients. MMR proteins were maintained in all cases of BPH. The study found a negative correlation between MMR protein loss and PCa ISUP grade groups. Progression-free survival (PFS) in patients with MMR deficiency was significantly shorter than in patients with maintained MMR expression.
CONCLUSIONS: CD9 protein expression was downregulated in PCa, compared to BPH, while CD63 protein expression was upregulated in high-grade PCa but downregulated in low-grade PCa. CD63 protein upregulation, CD9 downregulation, and loss of MMR protein characterized the shorter PFS of high-grade PCa patients. CD9, CD63, and MMR could be the routine immunohistochemical biomarkers for the diagnosis and risk stratification of PCa.

OBJECTIVE: To study an importance of new 2016 WHO histologic grading system for prostate cancer in evaluating the risk of progressing after conformal external beam radiation therapy, brachytherapy 125I and androgen deprivation therapy.
METHODS: A total of 53 patients with prostate acinar adenocarcinoma were undergone to conformal external beam radiation therapy, brachytherapy 125I and androgen deprivation therapy. Age of patients was 54-80 years (68.11+/-4.7 years). T3 and T2 prostate cancer was diagnosed in 42 (79.3%) and 11 (20,7%) patients, respectively. Baseline PSA level ranged from 5.5 ng/ml to 311 ng/ml (39.7+/-7.9 ng/ml). According to the new grading system (the WHO classification, 2016), all patients were divided into five risk groups.
RESULTS: Median follow-up was 64.9 months. The biochemical progression was seen in two patients, while three patients had metastatic disease. All patients with progressing prostate cancer were from IV and V prognostic groups. The 5-year progression-free survival rates for patients of IV-V and I-III groups were 44, 4% and 100%, respectively.
CONCLUSIONS: According to the results of combination treatment (conformal external beam radiotherapy, brachytherapy 125I and hormonal therapy), progression-free survival rate in patients of IV (Gleason 4+4=8) and V (Gleason 4+5=9 or 5+5=10) groups, according to new WHO grading system were significantly lower, in comparison with patients of I (Gleason 3+3=6), II (Gleason 3+4=7) and III groups (Gleason 4+3=7). Our study showed that new WHO classification allows to predict the progression of prostate cancer not only after prostatectomy, but also after conformal external beam radiation therapy, combined with brachytherapy 125I and androgen deprivation therapy.