Grade migration and important prognostic factors in a pathology specimen for radical radiotherapy in prostate cancer patients.

The study aimed to evaluate grade migration and prognosis depending on pathologic features in patients with prostate cancer treated with radical external beam radiotherapy. The study included 139 patients with an initial Gleason score of 7 (3+4 or 4+3) i.e., Grade Group 2-3 (GG2-GG3) treated between 2008 and 2013. The clinical outcome was assessed with respect to biochemical control (BC) and biochemical disease-free survival (bDFS). After re-evaluation, the majority of patients (96 patients - 69%) were up-graded from GG2-3. Finally, there were 4 patients (3%) with grade GG1, 12 patients (9%) - GG2, 27 patients (19%) - GG3, 51 patients (37%) - GG4 and 45 patients (32%) - GG5. In 42 patients (30%) a cribriform pattern was observed. Among the analyzed factors only the GGs were important for BC (p = 0.011) and the cribriform pattern was of borderline significance (p = 0.06). The 5-year biochemical control was 100% in GG1-3 and 84% in GG4-5. The 5-year biochemical control was 81% and 93%, if cribriform or no cribriform pattern was detected, respectively. In conclusion, re-evaluation and verification of pathology specimens in accordance with contemporary rules upgraded the Gleason score in the majority of patients. The aggressive behavior of prostate cancer starts to occur from GG 4. Cribriform pattern almost tripled the biochemical failure rate.

Differences in Gene Expression Profile of Primary Tumors in Metastatic and Non-Metastatic Papillary Thyroid Carcinoma-Do They Exist?

Molecular mechanisms of distant metastases (M1) in papillary thyroid cancer (PTC) are poorly understood. We attempted to analyze the gene expression profile in PTC primary tumors to seek the genes associated with M1 status and characterize their molecular function. One hundred and twenty-three patients, including 36 M1 cases, were subjected to transcriptome oligonucleotide microarray analyses: (set A-U133, set B-HG 1.0 ST) at transcript and gene group level (limma, gene set enrichment analysis (GSEA)). An additional independent set of 63 PTCs, including 9 M1 cases, was used to validate results by qPCR. The analysis on dataset A detected eleven transcripts showing significant differences in expression between metastatic and non-metastatic PTC. These genes were validated on microarray dataset B. The differential expression was positively confirmed for only two genes: IGFBP3, (most significant) and ECM1. However, when analyzed on an independent dataset by qPCR, the IGFBP3 gene showed no differences in expression. Gene group analysis showed differences mainly among immune-related transcripts, indicating the potential influence of tumor immune infiltration or signal within the primary tumor. The differences in gene expression profile between metastatic and non-metastatic PTC, if they exist, are subtle and potentially detectable only in large datasets.

The Spectroscopic Similarity between Breast Cancer Tissues and Lymph Nodes Obtained from Patients with and without Recurrence: A Preliminary Study.

Lymph nodes (LNs) play a very important role in the spread of cancer cells. Moreover, it was noticed that the morphology and chemical composition of the LNs change in the course of cancer development. Therefore, finding and monitoring similarities between these characteristics of the LNs and tumor tissues are essential to improve diagnostics and therapy of this dreadful disease. In the present study, we used Raman and Fourier transform infrared (FTIR) spectroscopies to compare the chemical composition of the breast cancer tissues and LNs collected from women without (I group-4 patients) and with (II group-4 patients) recurrence. It was shown that the similarity of the chemical composition of the breast tissues and LNs is typical for the II group of the patients. The average Raman spectrum of the breast cancer tissues from the I group was not characterized by vibrations in the 800-1000 cm-1 region originating from collagen and carbohydrates, which are typical for tumor-affected breast tissues. At the same time, this spectrum contains peaks at 1029 cm-1, corresponding to PO2- from DNA, RNA and phospholipids, and 1520 cm-1, which have been observed in normal breast tissues before. It was shown that Raman bands of the average LN spectrum of the II group associated with proteins and carbohydrates are more intensive than those of the breast tissues spectrum. The intensity of the Raman spectra collected from the samples of the II group is almost three times higher compared to the I group. The vibrations of carbohydrates and amide III are much more intensive in the II group's case. The Raman spectra of the breast cancer tissues and LNs of the II group's samples do not contain bands (e.g., 1520 cm-1) found in the Raman spectra of the normal breast tissues elsewhere. FTIR spectra of the LNs of the I group's women showed a lower level of vibrations corresponding to functional group building nucleic acid, collagen, carbohydrates, and proteins in comparison with the breast cancer tissues. Pearson's correlation test showed positive and more significant interplay between the nature of the breast tissues and LN spectra obtained for the II group of patients than that in the I group's spectra. Moreover, principal component analysis (PCA) showed that it is possible to distinguish Raman and FTIR spectra of the breast cancer tissues and LNs collected from women without recurrence of the disease.

Association of breast cancer grade with response to neoadjuvant chemotherapy assessed postoperatively.

Currently, breast cancer chemotherapy response can be predicted based on various parameters, with common reporting of tumour grade and Ki67 proliferation index. We analysed their association with pathological complete response (pCR) in a multivariate approach. The study was carried out in a group of 353 patients, treated by preoperative chemotherapy and prospectively observed. In selected patients, parallel to routing core needle biopsy assessment, gene expression profile of tumour was analysed by oligonucleotide microarrays. Tumour parameters associated with pCR in univariate analysis were: tumour grade, nuclear grade, mitotic index, Ki67, oestrogen and progesterone receptor (all p < 0.0001), and triple-negative status (p = 0.0032). The highest increase of pCR chance was observed in patients with high-grade tumours and with Ki67 ≥ 20%. In multivariate analysis, only tumour grade and oestrogen receptor status were predictive for pCR independently of other variables, with high grade increasing the odds of pCR 2.42 fold, and high ER decreasing the chance of pCR 0.41 fold. Tumour grading reflects important biological features of breast cancer and is not inferior to proliferation markers, including Ki67. It should be taken into account in decision-making for preoperative chemotherapy in parallel to breast cancer biologic subtypes, because grade 3 tumours exhibit a higher proportion of pCR.

Molecular profiles of thyroid cancer subtypes: Classification based on features of tissue revealed by mass spectrometry imaging.

Determination of the specific type of thyroid cancer is crucial for the prognosis and selection of treatment of this malignancy. However, in some cases appropriate classification is not possible based on histopathological features only, and it might be supported by molecular biomarkers. Here we aimed to characterize molecular profiles of different thyroid malignancies using mass spectrometry imaging (MSI) which enables the direct annotation of molecular features with morphological pictures of an analyzed tissue. Fifteen formalin-fixed paraffin-embedded tissue specimens corresponding to five major types of thyroid cancer were analyzed by MALDI-MSI after in-situ trypsin digestion, and the possibility of classification based on the results of unsupervised segmentation of MALDI images was tested. Novel method of semi-supervised detection of the cancer region of interest (ROI) was implemented. We found strong separation of medullary cancer from malignancies derived from thyroid epithelium, and separation of anaplastic cancer from differentiated cancers. Reliable classification of medullary and anaplastic cancers using an approach based on automated detection of cancer ROI was validated with independent samples. Moreover, extraction of spectra from tumor areas allowed the detection of molecular components that differentiated follicular cancer and two variants of papillary cancer (classical and follicular). We concluded that MALDI-MSI approach is a promising strategy in the search for biomarkers supporting classification of thyroid malignant tumors. This article is part of a Special Issue entitled: MALDI Imaging, edited by Dr. Corinna Henkel and Prof. Peter Hoffmann.

Prognostic significance of RBP2-H1 variant of JARID1B in melanoma.

BACKGROUND: Histone demethylase JARID1B plays several context dependent roles in epigenetic regulation of cellular differentiation in normal development and is highly expressed in multiple human cancers. The protein is a strong transcriptional repressor capable of downregulating numerous genes. There are three splicing isoforms of JARID1B, however the links between the protein structure and function are not clear. The expression pattern of JARID1B in human melanoma seems to be different from observed in other cancers. Moreover, up to now no data on the impact of JARID1B expression in cutaneous melanoma on the patients' prognosis have been reported. METHODS: We investigated immunohistochemically the association of intratumoral expression of total JARID1B protein and its RBP2-H1 isoform in primary and metastatic melanomas with prognosis for the patients. RESULTS: Expression of both total JARID1B protein and its RBP2-H1 variant was found in all the melanomas investigated. Our results indicate, however, that only high (above 90% of the cells) intratumoral expression of RBP2-H1 can be considered prognostic factor associated with worse overall survival of the patients. CONCLUSIONS: Such results if considered together with data demonstrating a switch to enhanced expression of RBP2-H1 at early stages of malignant transformation of melanocytes are in agreement with hypothetical crucial role of JARID1B in the course of melanoma development and progression and suggest that altered splicing of JARID1B may be important factor increasing melanoma aggressiveness.

Oral and oropharyngeal papillomas are not associated with high-risk human papillomavirus infection.

The role of different types of human papillomavirus (HPV) in the development of oral and oropharyngeal papillomas remains unclear. High-risk HPV (HR-HPV) was shown to be involved in the pathogenesis of significant proportion of squamous cell carcinomas of the oropharynx. In this study, we hypothesized that in some oropharyngeal papillomas, low-risk HPV (LR-HPV) and HR-HPV infection could co-exist, similar to what is observed in genital warts, and thus contribute to the elevated risk of malignancy. To test this hypothesis, we used real-time PCR to assess the presence of HPV DNA of 16 types (2 LR-HPV and 14 HR-HPV), in 75 formalin-fixed and paraffin-embedded histopathological samples of oral and oropharyngeal papillomas and in 57 squamous cell carcinomas from the same regions. We investigated the biological activity of HPV by demonstrating accumulation of P16(INK4A) protein in the viral-infected tissue samples. The presence of the LR-HPV genome from the HPV6 or HPV11 types was confirmed in 42 (56%) papillomas and in no carcinomas. HPV6/HPV11 co-infection was detected in 17 (22.7%) of the papillomas. HR-HPV DNA presence and HR-HPV activity hallmarks were not observed in any of the investigated papillomas. Thus, a causative role for HR-HPV or its contribution to LR/HR-HPV co-infection in the pathogenesis of oral or oropharyngeal papillomas is unlikely. Additionally, HR-HPV and LR-HPV infections seem to be mutually exclusive in papillomas and squamous cell carcinomas of the oral cavity and oropharynx.

The association of tumor lymphocyte infiltration with clinicopathological factors and survival in breast cancer.

Recent studies have confirmed the role of tumor-infiltrating lymphocytes (TILs) in carcinogenesis and cancer progression. The aim of this study was to evaluate the correlation between the level of tumor lymphocyte infiltration and well-known clinicopathological factors in breast cancer patients. We also evaluated the influence of TILs on overall survival. Paraffin sections were retrospectively evaluated in 76 cases in early stage breast cancer patients who underwent surgery followed by systemic treatment. Tumor-infiltrating lymphocytes were classified as absent (grade 0), mild (grade 1), moderate (grade 2), or severe (grade 3). Tumor-infiltrating lymphocytes were found in 87% of patients (severe grade in 8% of them). Higher grade (grades 2-3) TILs were present more frequently in younger patients (under 65 years) than older women (47% vs. 24%; p = 0.099). Higher grades of tumor-infiltrating lymphocytes (grades 2-3) appear to be associated with clinicopathological factors such as negative steroid receptor status (p = 0.001), HER2 overexpression (p = 0.016) and higher histological grade (G3) (p = 0.095). Tumor-infiltrating lymphocytes were not a significant prognostic factor for overall survival in our group. Only HER2 overexpression significantly increases the risk of death (HR = 4.3, p = 0.020). In the subgroup of patients who had tumors with HER2 overexpression there was non-significantly worse OS independently of TIL grade (p = 0.086).

Gene Expression (mRNA) Markers for Differentiating between Malignant and Benign Follicular Thyroid Tumours.

Distinguishing between follicular thyroid cancer (FTC) and follicular thyroid adenoma (FTA) constitutes a long-standing diagnostic problem resulting in equivocal histopathological diagnoses. There is therefore a need for additional molecular markers. To identify molecular differences between FTC and FTA, we analyzed the gene expression microarray data of 52 follicular neoplasms. We also performed a meta-analysis involving 14 studies employing high throughput methods (365 follicular neoplasms analyzed). Based on these two analyses, we selected 18 genes differentially expressed between FTA and FTC. We validated them by quantitative real-time polymerase chain reaction (qRT-PCR) in an independent set of 71 follicular neoplasms from formaldehyde-fixed paraffin embedded (FFPE) tissue material. We confirmed differential expression for 7 genes (CPQ, PLVAP, TFF3, ACVRL1, ZFYVE21, FAM189A2, and CLEC3B). Finally, we created a classifier that distinguished between FTC and FTA with an accuracy of 78%, sensitivity of 76%, and specificity of 80%, based on the expression of 4 genes (CPQ, PLVAP, TFF3, ACVRL1). In our study, we have demonstrated that meta-analysis is a valuable method for selecting possible molecular markers. Based on our results, we conclude that there might exist a plausible limit of gene classifier accuracy of approximately 80%, when follicular tumors are discriminated based on formalin-fixed postoperative material.

Histopathological factors influencing results of combined treatment in patients with laryngeal cancer.

The aim of the study was to assess the prognostic value of postoperative histopathological factors as well as the clinical usefulness of the modified risk score for recurrence. In a group of 197 patients with laryngeal cancer who underwent surgery followed by radiation therapy, partial resection was performed in 21.5% of patients and total resection in 78.5%. The majority of patients had T3 or T4 (74%) and N0 (63%) cancer. Macroscopically positive margins were reported in 10% of patients after partial resection and in 7% of patients after total resection, whereas microscopically positive margins were observed in 31% and 20% of cases, respectively. Extracapsular extension was observed in 22% of patients. In order to estimate local and nodal recurrence risk rates, criteria developed by Peters were used. Five-year local control (LC) was achieved in 88% of patients, disease-free survival (DFS) in 68% of patients and overall survival (OS) in 73% of patients. In the case of macroscopically positive margins, the 5-year DFS was 33% lower compared to radical surgery and 25% lower in the case of microscopically positive margins. The 5-year DFS was reduced by 29% due to extracapsular extension. Cox model analysis indicated that the degree of recurrence risk was the most potent independent prognostic factor for postoperative radiation therapy in laryngeal cancer. Negative histopathological factors influencing results of combined treatment of laryngeal cancer include macro- and microscopically positive margins, neck lymph node involvement and extracapsular extension.

The prognostic significance of indoleamine-2,3-dioxygenase and the receptors for transforming growth factor ß and interferon γ in metastatic lymph nodes in malignant melanoma.

We analyzed the prognostic significance of indoleamine-2,3-dioxygenase (IDO) and type 1 receptors for transforming growth factor beta (TGF-ßR1) and interferon gamma (IFN-γR1) in resected nodal metastases of 48 malignant melanoma patients. In 32 cases the corresponding skin tumors were available. We used immunohistochemical (IHC) staining which was assessed by pathologists and by a computer-aided algorithm that yielded quantitative results, both absolute and relative. We correlated the results with the patient outcome. We identified absolute computer-assessed IDO levels as positively correlated with increased risk of death in a multivariate model (HR = 1.02; 95% CI: 1.002-1.04; p = 0.03). In univariate analysis, patients with IDO levels below the median had a better overall survival time (30.3 vs. 17.5 months; p = 0.03). TGF-ßR1 and IFN-γR1 expression was modestly correlated (R = 0.34; p lt; 0.05) and TGF-ßR1 expression was lower in lymph nodes than in matched primary skin tumors (Z = 2.87; p = 0.004). The pathologists' and computer-aided IHC assessment demonstrated high correlation levels (R = 0.61, R = 0.74 and R = 0.88 for IDO, TGF-ßR1 and IFN-γR1, respectively). Indoleamine-2,3-dioxygenase is prognostic for the patient outcome in melanoma with nodal involvement and should be investigated prospectively for its predictive significance. IHC assessment by computer-aided methods is recommended as its gives IHC more objectivity and reproducibility. ecting mismatch repair deficiency. Association of CDX2 and PMS2 in the present study is necessary to conduct further genetic and pathological studies focusing on these two markers together.

Stromal, rather than epithelial cyclooxygenase-2 (COX-2) expression is associated with overall survival of breast cancer patients.

BACKGROUND: Prognostic value of enhanced COX-2 expression in breast cancer has been controversial for a long time. The opinions vary widely between studies. Moreover, significant majority of studies considered only COX-2 expression in cancer epithelial cells. METHODS: We examined the prognostic value of COX-2 expression in both epithelial and stromal cells using three different antibodies and three algorithms of immunohistochemical scoring and categorizing the tumours into COX-2 overexpressing groups. RESULTS: Our results demonstrate that COX-2 expression in stromal cells is independent prognostic factor indicating worse overall survival of patients. Such a result was obtained using each of the three antibodies and two of the algorithms used for evaluations of COX-2 expression levels. We also show that immunohistochemical assessment of the prognostic value of COX-2 expression in cancer epithelial cells depends to a large extent on a combination of primary antibodies and algorithms used for determination of the COX-2 over-expressing tumours. CONCLUSIONS: Our results indicate that stromal expression of COX-2 is independent prognostic parameter relatively insensitive to variations in sensitivity of antibodies used for its determination. Wide scatter of the published results concerning prognostic value of COX-2 expression in breast cancer tissues seems to be due to a large extent to multitude of antibodies and scoring algorithms used by different groups.

Case presentation - A five-year survival of the patient with glioblastoma brain tumor.

This paper presents an atypical case of a patient with brain tumor of the glioblastoma multiforme (GBM) type who achieved a 5-year survival. Some general information is provided including epidemiology, diagnostic and treatment procedures (surgery and radio-chemo-therapy), and prognosis of survival related to GBM. The course of the disease, including its main symptoms, individual reasons for the delay of adjuvant treatment, after the primary surgical treatment, 37-month period of the decease free survival, as well as comprehensive management after the tumor recurrence are also presented. Histopathology confirming the clinical diagnosis is discussed in a separate chapter.

PTEN expression profiles in colorectal adenocarcinoma and its precancerous lesions.

The aim of the study was to determine expression of the PTEN suppressor gene in colorectal adenocarcinoma and its precancerous lesions (adenomatous polyps) in correlation with common clinical and histopathological features. Forty-four patients with adenomatous polyps and 32 with primary adenocarcinoma of the colon or rectum were enrolled in the study. They underwent endoscopic removal of polyps or major surgery and postoperative adjuvant chemo- and radiotherapy depending on staging of the disease. No patient had received chemotherapy and/or radiotherapy before the surgery. PTEN expression was evaluated using immunohistochemical staining on paraffin-embedded specimens and compared to clinicopathological features of tumors. In colorectal cancers, PTEN expression was found to be significantly lower than in normal intestinal mucosa and adenomatous polyps. That was associated with complete loss of PTEN expression observed more frequently in colorectal cancer, contrary to reduction of PTEN expression occurring mostly in polyps. A correlation between polyp diameter and loss of PTEN was demonstrated as well as between tumor size and TNM advanced stage and PTEN expression. The obtained results suggest that the PTEN/PI3K/Akt pathway may play an important role in early stages of sporadic colorectal carcinogenesis and reduced PTEN expression in late oncogenesis is associated with some adverse clinical and pathological features.

Primary osteosarcoma of the thyroid gland - a case report.

A rare localization of primary osteosarcoma is presented. A woman aged 76 years was operated on for rapid growth of thyroid right lobe tumour. Histopathology showed anaplastic cancer with numerous foci of osseous metaplasia, negative with thyroglobulin, calcitonin, synaptophysin and chromogranin. A high proliferative activity of the tumour was observed (MIB-1 reaction) in the form of a positive reaction in approx. 40% of the tumour cell nuclei. The tumour stage was evaluated as pT4aNxMx according to the TNM scale. The reconsultation revealed negative staining with cytokeratin, and positive with vimentin, thereby confirming the mesenchymal origin of the tumour, with the final diagnosis being primary thyroid osteosarcoma. Taking into consideration the histopathological diagnosis, the extremely low radiation sensitivity of the tumour, the patient's age, the radical surgical treatment and persisting respiratory failure, radiotherapy was rejected in favour of further follow-up. The patient remains under oncological and endocrinological care.

Autopsy Histopathologic Lung Findings in Patients Treated With Extracorporeal Membrane Oxygenation.

CONTEXT.­: Extracorporeal membrane oxygenation (ECMO) is increasingly used in the treatment of respiratory and cardiac failure, but data describing lung histopathology in ECMO recipients are limited. OBJECTIVE.­: To examine pulmonary histopathologic findings in patients who underwent venovenous (VV) ECMO for pulmonary reasons, or venoarterial (VA) ECMO for cardiac indications shortly before death, and to determine if the pulmonary changes provided insights into therapy that may prevent complications and improve outcome. DESIGN.­: We conducted a retrospective study of lung autopsies, from VV and VA ECMO recipients and patients with acute respiratory distress syndrome (ARDS) and non-ECMO treatment, between 2008 and 2020 in Silesia Center for Heart Diseases in Zabrze, Poland. RESULTS.­: Among 83 ECMO patients (42-64 years; male, 57 [68.7%]), the most common histopathologic findings were bronchopneumonia (44 [53.0%]), interstitial edema (40 [48.2%]), diffuse alveolar damage (DAD; 32 [38.6%]), hemorrhagic infarct (28 [33.7%]), and pulmonary hemorrhage (25 [30.1%]). DAD was associated with longer ECMO treatment and longer hospital stay. The use of VV ECMO was a predictor of DAD in patients with ARDS and undergoing ECMO, but it also occurred in 21 of 65 patients (32.3%) in the VA ECMO group, even though VA ECMO was used for heart failure. CONCLUSIONS.­: Although DAD was significantly more common in lung autopsies of VV ECMO patients, one-third of VA ECMO patients had histopathologic changes characteristic of ARDS. The presence of DAD in lung autopsies of patients treated with VA ECMO indicates that in these patients, protective lung ventilation should be considered.

[Endometrial cancer in a 25-year-old patient. Case study]. / Rak blony sluzowej macicy u 25-letniej pacjentki. Opis przypadku.

Endometrial cancer is one of the most frequently diagnosed malignant neoplasms among women. In Poland, it is in the fourth place in terms of incidence. The highest morbidity concerns women aged 50-70 years, however it may also appear in women in their reproductive period. Endometrial cancer concerns about 3% of premenopausal women. We present a case of a 25-year-old patient who underwent endometrial curettage because of irregular menstrual bleeding for the last 5 months. Histopathology revealed endometrial cancer. We attempted to apply a conservative treatment. During the next 6 months the patient was treated with lynestrenol. After one month of hormonal therapy endometrial curettage was repeated. In histopathology endometrial tissues corresponding to the hormonal treatment were found. After 6 months of treatment hysteroscopy with endometrial biopsy followed by endometrial curettage, were performed. Hormonal treatment resulted in disease regression. About 5 months after successful treatment the patient conceived spontaneously. One year after she gave birth to her first child, she conceived spontaneously once more. Both children were born vaginally. In selected cases of atypical hyperplasia and early endometrial cancer in young women the attempt of hormonal treatment is acceptable.

Mucin secretion activity of gastric cancer as a prognostic factor: a clinicopathological analysis.

AIM OF THE STUDY: Gastric cancer is characterized by varying secretion of mucus. Mucin producing gastric carcinoma (MUC) is thought to be a histological subtype with a worse prognosis. The aim of this study was to compare the clinicopathological differences between MUC and other types of gastric carcinoma without secretion of mucus (NMUC). MATERIAL AND METHODS: WE REVIEWED TWO GROUPS OF PATIENTS WITH PATHOLOGICALLY CONFIRMED GASTRIC CANCER: 34 patients with MUC and 36 cases with NMUC. Patients' sex, age, tumor location, stage of disease and type in the Lauren classification were examined. We analyzed the presence of lymph node metastasis, peritoneal dissemination and liver metastasis. Additionally, treatment response, toxicity and survival rates were evaluated. RESULTS: We observed a statistically significant relationship between MUC subtype and patients' sex: MUC was found mostly in women (p = 0.017). There were no significant differences between the two gastric cancer groups according to age, tumor location, size of tumor or stage of disease. In the NMUC group the rate of liver metastasis was significantly higher (p = 0.001). The overall survival rate and progression-free survival for MUC patients were lower than those for NMUC patients. There was no significant difference in survival rates between the two groups. In analysis of logistic regression we distinguished significantly advantageous (number of chemotherapy cycles) and disadvantageous parameters (advanced stage in TNM), which influenced the chemotherapy effect. CONCLUSIONS: The MUC type itself is not an unequivocally negative prognostic agent. Poor prognosis was correlated with more advanced stages at diagnosis, particularly with dissemination of cancer.

Analysis of PTEN expression in large intestine polyps and its relation to the recognized histopathological and clinical risk factors for cancer development in this location.

AIM OF THE STUDY: PTEN is an important gene whose protein product is double specific phosphatase holding key regulatory functions in sending signals from membrane receptors for growth factors into the cell downstreams. Its participation, mainly by PI3K/AKT signaling pathway in the pathomechanism of many malignant cancers was unambiguously confirmed. The PTEN function gets disturbed on many levels and for various reasons. Disorders of PTEN protein expression seem to be even more common in many carcinomas. The aim of the study is to enquire the meaning of PTEN expression in the cancer transformation process in large intestine glandular polyps. MATERIAL AND METHODS: The group includes 40 patients, 21 men and 19 women, age median 64 years (51-83) qualified to endoscopic removal of large intestine polyp. Tissue material obtained during polyp removal endoscopy was immediately fixed in 4% buffered formalin solution with the mixture of phosphatase activity inhibitors (PhosStop Roche). Time of fixation 24-48 h. After fixation, the material was embedded in paraffin. PTEN visualization was based on specific rabbit monoclonal antibodies (Cell Signaling). The expression of PTEN protein in large intestine and rectum polyps was marked by a semi-quantitative method and an attempt to correlate the results with the acknowledged clinical and histopathological malignancy risk factors was undertaken. RESULTS: Loss or weakening of protein expression was found in 45% cases. Moreover, the relationship between polyp diameter and a loss of PTEN expression was proved. The received results can indicate a significant participation of PTEN gene in early oncogenesis stages of large intestine cancer.