<p><strong>Introduction.</strong> Extramural venous invasion (EMVI) is a significant predictive factor of the prognosis for patients with colorectal carcinoma and it is directly connected with the relapse of a disease, especially with the appearance of distant metastases. <strong>Methods.</strong> The research comprises 90 patients with colorectal cancer. Representative samples of tumor tissues obtained by surgical resection are fixed in 4% formalin and embedded into paraffin blocks. Semi-series incisions of 4&mu;m thickness were stained by HE method and Van Gieson&rsquo;s method. <strong>Results. </strong>Out of 90 analyzed patients, 21 (23,33%) were with EMVI, and 69 (76.67%) without EMVI on the histological preparations stained by HE method. EMVI was found in 7 more tumors on the preparations stained by Van Gieson&rsquo;s method. Sensitivity of the method determining EMVI on the histological preparations stained by Van Gieson&rsquo;s method was better for 25% (7/28) than on the preparations stained by HE method. EMVI was not found in patients at A and B1 stage of disease according to Astler- Coller classification, but out of 77 patients which were at B2, C1 and C2 stage EMVI was found in 28 (36,36%) patients, p&le;0,01. EMVI was found in 18/77 (23,38%) patients who had a tumor of low histological gradus, p&le;0,01 and in 10/13 (76,92%) patients who had a tumor of high histological gradus, p&le;0,01. In patients with neural invasion, EMVI was found in 18/22 (81,82%), whereas in patients without neural invasion EMVI was found in 10/68 (14,71%), p&le;0,01. In patients with weak intensity of peritumoral lymphocytic reaction EMVI was found in 20/41 (48,78%) whereas in patients with moderate and noticeable level it was found in 8/49 (16,33%), p&le;0,01. There was a significant correlation between extramural venous invasion and other parameters of unfavorable prognosis. <strong>Conclusion.</strong> EMVI is an important indicator in administration of postoperative adjuvant therapy in patients with colorectal carcinoma. A special histochemical method of elastic fiber stain should be applied in everyday practice when EMVI is not found on HE stained preparations in patients with CRC.</p>

<p><strong>Introduction. </strong>The Bcl-2 gene codes an oncoprotein, inhibits a programmed cell death or apoptosis and it plays a very important role in colorectal cancerogenesis. The aim of our study is to determine Bcl-2 expression in colorectal carcinomas in relation with the stage of disease, histology of tumor type, localization and macroscopic growth pattern. <strong>Methods.</strong> Immunohistochemichal detection of Bcl-2 protein expression was carried out on 90 resected colorectal carcinomas. The patients were divided into three groups according to the degree of Bcl-2 expression in a tumor: group 0 - there were no cells with positive immunohistochemical reaction; group I- up to 20 % of positive cells, and group II- above 20% of positive cells. The groups were compared in relation to the stage of disease, T stage of local spread of disease, histology of tumor type, localization and macroscopic growth pattern. <strong>Results.</strong> 58% of patients at the second stage of disease had no expression of Bcl-2. Higher percentage (61%) of the patients with metastases ( stages III and IV) had high level of Bcl-2 expression. Tumors with polipoid growth pattern have higher level of Bcl-2 expression. <strong>Conclusion. </strong>There is a statisticaly significant difference in Bcl-2 protein expression in patients surgically treated at the II and III stage of disease, stage T3a/b, T3c/d of local spread of disease and tumors whith polipoid growth pattern in relation to infiltrative growth pattern.</p>