Article
PATHOHISTOLOGICAL AND IMMUNOHISTOCHEMICAL FEATURES OF PROSTATIC CANCER
| About the author: | Krutenko O. V. |
| Heading | EXPERIMENTAL MEDICINE |
| Type of article | Scentific article |
| Annotation | Prostate cancer (PC) is one of the most common cancers, which is about 12% in the structure of morbidity men and ranks second in the structure of mortality from malignant neoplasm. Diagnosis of PC based on the determination of prostate-specific antigen (PSA) in blood serum and pathological study of intraoperative and biopsy material. There are several histological types of PC. The most common form is acinar cell carcinoma (ACC), which occurs in 95% of all cases of prostate cancer, and ductal adenocarcinoma (DAC) of the prostate gland, which is about 1% of all prostate cancer. Histological and immunohistochemical (IHC) features of various forms of prostate cancer have been studied insufficiently. The aim of the research was to determine the histopathological and immunohistochemical features of PC. Material and methods. The comprehensive research conducted on postoperative material of 40 patients aged 52 to 75 years, with histopathological verified diagnosis of PC. Microscopic examination of histopathological slides defined histological type of tumor and evaluate the degree of malignancy Gleason system. IHC studies were performed using primary monoclonal antibody against Ki-67 Antigen, AMACR, CK HMW, PSA and AR. Statistical analysis included calculation of mean value (M) and standard deviation (σ). Probability differences comparable values were determined by Student's t test (T); results considered likely at p<0.05. Results and discussion. Complex histopathological research showed that among the 40 patients with PC who underwent radical prostatectomy, ACC was verified in 25 cases (62.5%); PAC – in 15 cases (37.5%). In all cases, ACC noted a high level in terms of malignancy Gleason (G3 – 7–10 points), while the PAC gradation by Gleason in 8 cases (53.3%) was 5–6 points (G2), and in 7 cases (46.7%) – 7–10 points (G3). IHC study showed that PAC and ACC were characterized by high levels of PSA expression. The nature immunostaining ranged from moderate to strong DAB-staining cytoplasm of cancer cells in acinar and ductular malignant structures. The average index of the relative number of immunopositive cells was 95,14±3,08% in patients with ACC, and 78,65±12,35% in patients with PAC (p<0,05). In the study of the expression of AR in the cancer cells was found that both the ACC, and for most of the PAC characteristic bright nuclear immunostaining pattern almost all tumor cells. The average index of the relative amount of AR-positive cells was 97,35±2,15 in patients with ACC, and 96,48±2,36 in patients with PAC (p>0,05). Meanwhile, the 4 cases of PAC (26.7%) and 5 cases of ACC (20.8%) were identified weak nuclear DAB-staining in less than 50% of malignant cells. Depression of AR expression level can cause reduction of tumor response to hormone therapy. In addition, we conducted a determining basal cell marker AMACR (P504S), and high molecular weight cytokeratin (CK HMW). Pattern of AMACR immunostaining was characterized by moderate or distinctive granular cytoplasmic expression of the marker in most tumor cells. For CK HMW was characteristic expressive immunostaining of basal cells, whereas secretory cells remained immunonegative or observed only focal weak immunostaining. Also, moderate and distinct expression of this marker is observed in malignant prostate cancer cells in the foci of squamous differentiation. Lack CK HMW-positive basal cells and basal membranes in AMACR-positive sites was observed only in cases of PAC. Positive expression as AMACR, and CK HMW was absent in non-tumor tissue surrounding the malignant structures of PC. Determination of cell proliferation index in terms of expression of Ki-67 antigen showed that the proliferative activity of cancer cells ACC is significantly higher than in the PAC. Thus, the average index of cell proliferation by B. Risberg et al. (2002) in ACC was 3,75±0,55 points, while the rate in PAC was 2,54±0,62 points (p<0,05). Pattern of immunostaining using clone MIB-1 characterized by distinct nuclear expression of strong diffuse DAB-staining nuclei of malignant cells and a complete lack of nonspecific staining cytoplasm. Thus, the use of IHC method can increase specificity and likelihood morphological definition of PC even in small volume pieces of prostate tissue. Also, due to the strong immunostaining of malignant structures using IHC markers allows to determine the likely distribution intraductal PAC zone and extracapsular tumor invasion. |
| Tags | prostatic cancer, immunohistochemical staining, prostate-specific antigen, proliferation |
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| Publication of the article | «World of Medicine and Biology» №4(58), 2016 year, 113-115 pages, index UDK 616.65-018+616.006.6-091:577.218+616-091.8/616-097 |