Biomedical subjects

Lars Egevad

Publications and source records attributed to Lars Egevad.

At least 37 records · Page 2Linked to original sources

PubMed2005

Tumor size, vascular density and proliferation as prognostic markers in GS 6 and GS 7 prostate tumors in patients with long follow-up and non-curative treatment.

OBJECTIVES: To investigate the prognostic value of potential markers in localized, Gleason score 6 and 7 prostate cancer (PC). METHODS: From a consecutive series of men with PC diagnosed at transurethral resection (1975-1990), specimens from 132 patients without metastases, with Gleason score (GS) 6 (n=80) or 7 (n=52) tumors followed with watchful waiting were examined. The fraction of resected prostate tissue containing cancer, the micro-vessel density (v.d.) when stained for endoglin or von Willebrand factor (vWf), and the percentage of Ki-67 labeled tumor cells were measured using immunohistochemistry. RESULTS: High levels of vWf v.d., endoglin v.d., and percent cancer of the TURP specimen were significantly associated with short cancer-specific survival in Kaplan-Meier analysis of all patients with GS 6 and 7 tumors. Interestingly, a combined estimate of percent cancer and vWF v.d. could be used to identify a large subset (50%) of GS 6 tumors with only a 2.5% risk of PC death within 15 years. None of the tested markers gave independent prognostic information for the GS 7 tumors. CONCLUSIONS: Estimates of tumor size and vascular density may identify a large proportion of non-aggressive GS 6, but not GS 7, tumors.

Age Factors↗

PubMed2005

Current practice of Gleason grading among genitourinary pathologists.

There is consensus that the Gleason system should be used for grading of prostate cancer. However, a number of controversial issues remain as regards how this grading is applied. A questionnaire was sent to 91 genitourinary pathologists in countries around the world with the purpose to survey current practice of Gleason grading. The response rate was 74%, including 43 North American pathologists and 24 from other continents. Of all participants, only 13% and 36%, respectively, ever diagnosed a Gleason score (GS) of 2 to 3 or 4 on needle biopsies (NBX), and 88% of those who did so assigned a GS 4 to <1% of cancers. Cribriform Gleason pattern (GP) 3 was acknowledged by 88% but a majority of them would classify < or =20% of cribriform patterns as GP 3. One third only accepted cribriform or fusion patterns as GP 4, but two thirds also included incomplete or poorly defined glands. For GP 5 to be identified on NBX, 83% required clusters of individual cells, strands, or nests seen at less than x40 lens magnification. Only 26% defined GS on NBX as primary + tertiary GP, and a majority would mention a tertiary pattern separately. For NBX, global or highest GS was reported by 40% and 10%, respectively, whereas 46% only gave a separate GS for each individual NBX core. In conclusion, there is a need to standardize practical application of Gleason grading both in terms of interpretation of patterns as well as how grading is reported. Our survey data provide information to general pathologists about the most common grading practices among genitourinary pathologists.

Adult↗

PubMed2005

Prediction of the volume of large prostate cancers by multiple core biopsies.

OBJECTIVE: To evaluate whether large-volume prostate cancers can be predicted by means of multiple needle biopsies. MATERIAL AND METHODS: In 115 men, 8-14 (mean 10) biopsies were taken, including eight from standardized positions (apex, mid-medial, mid-lateral and base). Biopsies were reviewed, the length of the cancer measured and the percentage cancer length calculated. All men underwent radical prostatectomy. The prostatectomy specimens were totally embedded and the tumor volume was measured planimetrically. The predictive values of the number and percentage of cores positive for cancer, cancer length and percentage cancer length were calculated for tumor volumes of >4, >6 and >8 ml. RESULTS: Using univariate logistic regression, cancer length and percentage cancer length predicted tumor volumes of >4 (p<0.001), >6 (p<0.001) and >8 ml (p<0.05). These measures were better predictors of tumor volume than the number and percentage of cores positive for cancer. A biopsy cancer length of > or =30 mm and a percentage cancer length of > or =25% predicted a tumor volume of >4 ml in 95% and 93% of cases, respectively. For tumor volumes of >6 or >8 ml, predictive values were lower. Tumor volumes of <2 and <4 ml were found in 13% and 35%, respectively of men with as many as six positive cores, indicating that the number of positive cores was less useful as a predictor of tumor volume than the cancer length. CONCLUSIONS: Cancer length and percentage cancer length are significant predictors of large tumor volumes. It is recommended that the linear extent of cancer in prostate biopsies should be reported by the pathologist.

Adult↗

PubMed2005

The significance of tumor heterogeneity for prediction of DNA ploidy of prostate cancer.

OBJECTIVE: In a previous study, we mapped the ploidy heterogeneity of prostate cancer using flow cytometry in 676 tumor samples from 50 radical prostatectomy specimens. Ploidy heterogeneity was common (42% of tumors) and was found in all non-diploid tumors. The volume of non-diploid tumor was estimated and found to predict extra-prostatic extension and seminal vesicle invasion. The aim of this study was to evaluate the impact of tumor heterogeneity on preoperative ploidy assessment. MATERIAL AND METHODS: In 50 men at least six core biopsies were taken before prostatectomy. Sections from biopsies with cancer were Feulgen-stained for image cytometry. After exclusion of biopsies with insufficient material, 123 histograms from 48 men (mean 2.6; range 1-7) remained for analysis. RESULTS: In 32 men, biopsies were diploid. In 16 men, at least one biopsy was non-diploid (14 tetraploid, two aneuploid) and 10 of them also had diploid biopsies. In 34 men (71%), the prostatectomy specimens were correctly predicted as being either diploid (48%) or non-diploid (23%). The sensitivity and specificity of biopsies for predicting non-diploid cancer were 55% and 82%, respectively, and the positive and negative predictive values were 69% and 72%, respectively. The ploidy status of tumors with and without ploidy heterogeneity was correctly predicted in 55% and 82% of cases, respectively (p=0.04). Biopsies underestimated ploidy in 9/20 tumors (45%) with heterogeneous ploidy status. Underestimation mainly occurred when one or two cores were analyzed. CONCLUSIONS: Preoperative prediction of the ploidy status of prostate cancer is hampered by tumor heterogeneity. Analysis of multiple biopsies is important for correct preoperative ploidy estimation.

Aged↗

PubMed2005

Prognostic and predictive factors in prostate cancer: historical perspectives and recent international consensus initiatives.

An understanding of prognosis in cancer medicine is important for patient care, research and cancer control programs. In prostate cancer, prognostic (predictive) factors are particularly important given the marked heterogeneity of this disease at clinical, morphologic and biomolecular levels. Clinical stage and histologic grade have historically played major roles in defining heterogeneity in prostate cancer. More recently, serum prostate-specific antigen measurement has assumed a significant prognostic role. Over the last two decades there has been an explosion of research into biomarkers, many of which have been purported to have prognostic significance. In this paper we present an overview of the various consensus initiatives that have transpired over the last dozen years. Criteria for evaluating prognostic factors and classifications of predictive factors have emerged that have proven useful and advanced our understanding of the biology of prostate cancer. The results of these consensus initiatives form a foundation on which the current international consultation on prognosis (prediction) in prostate cancer is built. Advances in our understanding of the new and promising prognostic factors will require a more rigorous evidence-based approach to the analysis of published studies. Furthermore, appropriate mathematical models for the analysis of the multiple factors that influence a prognostic system will have to be employed.

Adenocarcinoma↗

PubMed2005

Prognostic and predictive factors and reporting of prostate carcinoma in prostate needle biopsy specimens.

The information provided in the surgical pathology report of a prostate needle biopsy of carcinoma has become critical in the subsequent management and prognostication of the cancer. The surgical pathology report should thus be comprehensive and yet succinct in providing relevant information consistently to urologists, radiation oncologists and oncologists and, thereby, to the patient. This paper reflects the current recommendations of the 2004 World Health Organization-sponsored International Consultation, which was co-sponsored by the College of American Pathologists. It builds on the existing work of several organizations, including the College of American Pathologists, the Association of Directors of Anatomic and Surgical Pathologists, the Royal Society of Pathologists, the European Society of Urologic Pathology and the European Randomized Study of Screening for Prostate Cancer.

Biomarkers, Tumor↗

PubMed2005

Prognostic factors and reporting of prostate carcinoma in radical prostatectomy and pelvic lymphadenectomy specimens.

This paper, based on the activity of the Morphology-Based Prognostic Factors Committee of the 2004 World Health Organization-sponsored International Consultation, describes various methods of handling radical prostatectomy specimens for both routine clinical use and research purposes. The correlation between radical prostatectomy findings and postoperative failure is discussed in detail. This includes issues relating to pelvic lymph node involvement, detected both at the time of frozen section and in permanent sections. Issues of seminal vesicle invasion, including its definition, routes of invasion and relationship to prognosis, are covered in detail. The definition, terminology and incidence of extra-prostatic extension are elucidated, along with its prognostic significance relating to location and extent. Margins of resection are covered in terms of their definition, the etiology, incidence and sites of positive margins, the use of frozen sections to assess the margins and the relationship between margin positivity and prognosis. Issues relating to grade within the radical prostatectomy specimen are covered in depth, including novel ways of reporting Gleason grade and the concept of tertiary Gleason patterns. Tumor volume, tumor location, vascular invasion and perineural invasion are the final variables discussed relating to the prognosis of radical prostatectomy specimens. The use of multivariate analysis to predict progression is discussed, together with proposed modifications to the TNM system. Finally, biomarkers to predict progression following radical prostatectomy are described, including DNA ploidy, microvessel density, Ki-67, neuroendocrine differentiation, p53, p21, p27, Bcl-2, Her-2/neu, E-cadherin, CD44, retinoblastoma proteins, apoptotic index, androgen receptor status, expression of prostate-specific antigen and prostatic-specific acid phosphatase and nuclear morphometry.

Biomarkers, Tumor↗

PubMed2005

Proteomic analysis of protein expression in prostate cancer.

OBJECTIVE: To investigate protein expression in prostate cancer using 2-dimensional gel electrophoresis (2-DE) and mass spectrometry. STUDY DESIGN: Cells were collected from 29 peripheral zone tumors and from benign tissue by scraping cut surfaces of radical prostatectomy specimens. Samples were suspended in a medium with protease inhibitors and prepared for 2-DE. Gels were analyzed, and protein spots that differed quantitatively between tumor and benign tissue were identified via mass spectrometric fingerprinting of tryptic fragments and tandem mass spectrometry sequence analysis. RESULTS: In total, 63 spots differed between cancer and benign samples (p < 0.01); 56 were overexpressed (> 1.5 fold) in cancer and 7 underexpressed (< 0.6 fold). Among overexpressed proteins were transcription factors (nucleoside diphosphate kinase 1) and enzymes involved in gene silencing (chromobox protein), protein synthesis (39S ribosomal protein L12, BiP protein, protein disulfide isomerase), degradation (cytosol aminopeptidase, endopeptidase Clp, inorganic pyrophosphatase) and energy metabolism (acyl-CoA dehydrogenase, isocitrate dehydrogenase, NADH-ubiquinone oxidoreductase, pyruvate dehydrogenase), heat-shock proteins (60 and 70 kd), structural proteins (cytokeratins) and membrane proteins (stomatinlike protein 2). CONCLUSION: The protein profile of prostate cancer differs from that of benign tissue. Several potential target proteins for detection or evaluation of prognosis in prostate cancer were identified.

Electrophoresis, Gel, Two-Dimensional↗

PubMed2004

Pim-1 expression in prostatic intraepithelial neoplasia and human prostate cancer.

BACKGROUND: PIM-1, an oncogene product of serine/threonine kinase, has been found to play an important role in induction/suppression of apoptosis, cell cycle progression, and transcriptional regulation by phosphorylating the target proteins involved in these processes. Recently, the expression of PIM-1 has been shown to correlate significantly with measures of prostate cancer clinical outcome. METHODS: Immunohistochemical analysis was used to characterize the patterns of PIM-1 expression in high grade prostatic intraepithelial neoplasia (HGPIN) and cancer in 121 radical prostatectomy specimens. RESULTS: Moderate to strong cytoplasmic staining was observed in 68% of cancers, 12% presented nuclear positivity as well. Moderate to strong expression was seen in 76% of tumors with Gleason score (GS) 7 or higher compared to 58% in tumors with GS 6 or lower (P = 0.04). The staining intensity was moderate or strong in 97% of HGPIN lesions. PIM-1 was overexpressed in HGPIN compared to cancer in 65% of cases. Expression in benign glands was negative or only weakly positive. CONCLUSION: Our data suggest that PIM-1 overexpression in HGPIN may be an early event in the development of prostate malignancy. Additionally, PIM-1 expression provides supplementary information for distinguishing HGPIN from benign epithelium.

Aged↗

PubMed2004

Interobserver reproducibility of modified Gleason score in radical prostatectomy specimens.

The Gleason score (GS) of prostate cancer is calculated by adding primary and secondary Gleason grades with patterns occupying less than 5% of the tumour often not included despite their probable prognostic significance. A modified Gleason score (mGS) comprising primary and tertiary patterns of higher grade has been proposed, but its interobserver variability has yet to be elucidated. Slides from 69 consecutive prostatectomy specimens were circulated among four genitourinary pathologists. GS and mGS were assessed, and results were compared in pairs. Mean weighted kappa for GS and mGS were 0.56 (range 0.52-0.66) and 0.58 (range 0.49-0.74), respectively. The difference between GS and mGS was 0, 1 and 2 score units in 66%, 26% and 8%, respectively, mean 0.41 score units (range 0.24-0.51). The increment was greater for transition-zone tumours than for peripheral-zone tumours (0.63 and 0.35 score units, respectively, P=0.002). An odd mGS (5, 7 or 9) was more often given than an odd GS (77% and 62%, respectively, P<0.001). Disagreement between observers greater than 1 score unit was more common with mGS than GS (18% and 4%, respectively, P<0.001). In conclusion, overall mean weighted kappa for interobserver reproducibility of mGS is at least as high as that of GS. However, there is a clustering of mGS in odd scores, and severe disagreement is more commonly observed than with GS. Training of mGS assessment would possibly improve agreement. Tertiary Gleason patterns need to be better defined.

Humans↗

PubMed2004

Gene expression profiling identifies clinically relevant subtypes of prostate cancer.

Prostate cancer, a leading cause of cancer death, displays a broad range of clinical behavior from relatively indolent to aggressive metastatic disease. To explore potential molecular variation underlying this clinical heterogeneity, we profiled gene expression in 62 primary prostate tumors, as well as 41 normal prostate specimens and nine lymph node metastases, using cDNA microarrays containing approximately 26,000 genes. Unsupervised hierarchical clustering readily distinguished tumors from normal samples, and further identified three subclasses of prostate tumors based on distinct patterns of gene expression. High-grade and advanced stage tumors, as well as tumors associated with recurrence, were disproportionately represented among two of the three subtypes, one of which also included most lymph node metastases. To further characterize the clinical relevance of tumor subtypes, we evaluated as surrogate markers two genes differentially expressed among tumor subgroups by using immunohistochemistry on tissue microarrays representing an independent set of 225 prostate tumors. Positive staining for MUC1, a gene highly expressed in the subgroups with "aggressive" clinicopathological features, was associated with an elevated risk of recurrence (P = 0.003), whereas strong staining for AZGP1, a gene highly expressed in the other subgroup, was associated with a decreased risk of recurrence (P = 0.0008). In multivariate analysis, MUC1 and AZGP1 staining were strong predictors of tumor recurrence independent of tumor grade, stage, and preoperative prostate-specific antigen levels. Our results suggest that prostate tumors can be usefully classified according to their gene expression patterns, and these tumor subtypes may provide a basis for improved prognostication and treatment stratification.

Biomarkers, Tumor↗

PubMed2004

Fruits and vegetables and prostate cancer: no association among 1104 cases in a prospective study of 130544 men in the European Prospective Investigation into Cancer and Nutrition (EPIC).

We examined the association between self-reported consumption of fruits and vegetables and prostate cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC). Data on food consumption and complete follow-up for cancer incidence were available for 130544 men in 7 countries recruited into EPIC between 1993 and 1999. After an average of 4.8 years of follow-up, there were 1104 incident cases of prostate cancer. The associations of consumption of total fruits, total vegetables, cruciferous vegetables and combined total fruits and vegetables with prostate cancer risk were examined using Cox regression, stratified for recruitment center and adjusted for height, weight and energy intake. There was a wide range in consumption of fruits and vegetables: mean intakes (g/day) in the bottom and top fifths of the distribution, as estimated from 24-hr recalls in a subsample of participants, were 53.2 and 410.7 for fruits, 97.1 and 242.1 for vegetables and 169.0 and 633.7 for fruits and vegetables combined. No significant associations between fruit and vegetable consumption and prostate cancer risk were observed. Relative risks (95% confidence intervals) in the top fifth of the distribution of consumption, compared to the bottom fifth, were 1.06 (0.84-1.34) for total fruits, 1.00 (0.81-1.22) for total vegetables and 1.00 (0.79-1.26) for total fruits and vegetables combined; intake of cruciferous vegetables was not associated with risk. These results suggest that total consumption of fruits and vegetables is not associated with the risk for prostate cancer.

Adult↗

PubMed2004

Expression of ezrin in prostatic intraepithelial neoplasia.

OBJECTIVES: To study the protein expression and gene copy number of ezrin in a set of high-grade prostatic intraepithelial neoplasia (HGPIN) samples with concomitant prostate cancer. Ezrin is a cytoskeleton linker protein that is actively involved in regulating the growth and metastatic capacity of cancer cells. METHODS: Nineteen HGPIN samples obtained from radical prostatectomy specimens were used for the study. Among them, 13 samples also contained invasive prostate cancer. The expression of ezrin was studied by immunohistochemistry. The same samples were also used for fluorescence in situ hybridization to study the gene copy number of ezrin. RESULTS: Immunoreactivity for ezrin was absent or weak in benign prostatic epithelial cells. Weak or moderate immunostaining was detected in 11 of 13 prostate cancer specimens. However, the immunostaining was moderate or strong in all HGPIN samples. In addition, whenever HGPIN and prostate cancer were found in the same sample, the staining was always more intense in the HGPIN cells than in the cancer cells. No alteration was found in the gene copy number detected by fluorescence in situ hybridization. CONCLUSIONS: We have shown that ezrin is overexpressed in HGPIN and prostate cancer compared with adjacent benign prostatic epithelium. In addition, HGPIN has a greater expression level of ezrin compared with that of prostate cancer. Our results indicate that aberrant expression of ezrin might be involved in the pathogenesis of prostate cancer, and ezrin expression may be useful for the diagnosis of HGPIN.

Adenocarcinoma↗

PubMed2004

Interobserver reproducibility of percent Gleason grade 4/5 in prostate biopsies.

PURPOSE: Percent Gleason grade 4/5 (GG4/5) has been proposed as a predictor of prognosis in prostate cancer and it has been shown to add prognostic information to that given by Gleason score (GS). We recently noted that the interobserver reproducibility of percent GG4/5 in total prostatectomy specimens is at least as good as that of the GS. However, to our knowledge the reproducibility of percent GG4/5 in needle biopsies has not yet been investigated. MATERIALS AND METHODS: A consecutive series of needle biopsies from 69 men with prostate cancer was reviewed. Biopsies were taken according to a standardized octant protocol. All 279 slides containing cancer were circulated among 4 genitourinary pathologists, who assessed GS and percent GG4/5. Results were compared pairwise and weighted kappa was calculated. RESULTS: The 4 observers had a mean weighted kappa for GS and percent GG4/5 of 0.48 to 0.55 (overall mean 0.51) and 0.52 to 0.68 (overall mean 0.60), respectively. There was less disagreement in percent GG4/5 when a single biopsy was positive for cancer than when 6 or more biopsies were positive. The number of positive biopsies showed a stronger correlation with a discrepancy in percent GG4/5 than cancer length. Disagreement was worse when cribriform or fusion patterns were present. CONCLUSIONS: Interobserver reproducibility of percent GG4/5 on prostate biopsies is at least as good as that of GS. Hence, concern about interobserver variability should not deter pathologists from using percent GG4/5. Grading appears to be most difficult when cancer is present in multiple biopsies or it contains cribriform or fusion patterns.

Aged↗

PubMed2003

Overexpression of IGBFB2 is a marker for malignant transformation in prostate epithelium.

Insulin-like growth factor binding protein 2 (IGFBP2) has been shown to be overexpressed in prostatic intraepithelial neoplasia (PIN) and invasive cancer and the serum level to parallel that of prostate-specific antigen (PSA) in prostate cancer. A combination of cDNA and tissue microarray results recently demonstrated overexpression of IGFBP2 in hormone refractory prostate cancer, indicating that the IGF system may be part of a key growth regulatory pathway in prostate cancer. The present study reexamines the immunohistochemical expression of IGFBP2 and its relationship to grade in tissue from 193 radical prostatectomy specimens from patients with localized prostate adenocarcinoma. We found a significant overexpression of IGFBP2 in all instances of PIN and in more than 90% of cancers regardless of the grade. An intense overexpression was noted in the neuroendocrine cells in normal glands as well as in cancer. The IGFBP2 expression was also analyzed in 18 cases of biopsy diagnosed prostate cancer. In all these cases, the glands interpreted as invasive cancer in hematoxylin-eosin stained sections overexpressed IGFBP2, without a significant correlation to grade. We conclude that overexpression of IGFBP2 is a powerful marker for malignant transformation in the prostate epithelium and suggest that optimized immunohistochemical detection of IGFBP2 expression may be an adjunct tool in the diagnosis of prostate cancer.

Adenocarcinoma↗

PubMed2003

Cytology of the central zone of the prostate.

The prostate has three anatomical regions: the peripheral, transition, and central zones (CZ). The CZ has distinct histological features, but its cytological morphology has not been described. This study was done on surgical specimens to ensure that samples were representative of the CZ, and that no prostatic intraepithelial neoplasia (PIN) or cancer contaminated the smears. An incision was made in the CZ of 51 prostatectomy specimens, and cells were scraped from cut surfaces. After exclusion of samples contaminated by PIN or cancer or with poor cell yield, 39 Giemsa-stained smears remained for analysis. Large branching epithelial sheets with geographic architecture and crowded nuclei were seen in 97% of smears. Epithelial clusters with elongated palisaded nuclei were identified in 80% of cases, but were always a minor component. Visible nucleoli (97%), cytoplasmic vacuoles (97%), and smooth muscle cells in the background (95%) were common. Blue-green cytoplasmic granules resembling seminal vesicle pigment were seen in 97%. Magenta-colored cytoplasmic pigment, similar to granules seen in other regions of the prostate, was found in 74%. Recognition of CZ epithelium as a benign constituent of prostate cytology is important because elongated cells, crowded nuclei, and visible nucleoli may otherwise be misinterpreted as PIN or cancer.

Aged↗

PubMed2003

VHL down-regulation and differential localization as mechanisms in tumorigenesis.

BACKGROUND: The von Hippel-Lindau (VHL) gene has been widely analyzed in many tumors. Early studies in animal tumors suggest that changes in VHL protein level and localization may be also important in tumorigenesis. In this study, we determined the role of VHL protein in human renal cell carcinomas. METHODS: Seventy-five human renal cell carcinomas, predominantly of clear cell type (60 of 75), were examined for VHL protein by immunohistochemistry. The level and pattern of protein expression were then compared to VHL mutations and tumor characteristics. RESULTS: An apparent decline of VHL level (positive in <50% of tumor cells) was observed in 49 (65%) tumors, a change more frequent than VHL mutations (28 of 75) (37%). In tumors, VHL was localized to the cytoplasm and/or the cell membrane. The occurrence of a predominantly membranous signal was significantly associated with missense mutations (9 of 14 tumors with missense mutations versus 14 of 61 tumors with no or nonmissense mutations, P = 0.0025) and tumor stage (23 of 60 tumors with stage TI versus 0 of 15 tumors with TII and TIII, P = 0.0034). CONCLUSION: This study provides the first evidence of the role of VHL protein level and intracellular localization in tumorigenesis in humans.

Antibodies↗

PubMed2002

Ultrastructure of the secretion of prostasomes from benign and malignant epithelial cells in the prostate.

BACKGROUND: Prostate epithelial cells are producing, among other things, a fluid secretion containing small bodies, the prostasomes. The mechanism of synthesis of the prostasomes is not known in details, neither is it known whether the mode of prostasome production changes at a neoplastic transformation of the prostate cells. Due to the small size of the prostasomes, we have used electron microscopy for evaluating the production and distribution of prostasomes in benign and neoplastic cells of the prostate. METHODS: Benign and neoplastic areas in plastic embedded core biopsy specimens of prostate tissue were identified, and secreting cells were selected. The corresponding areas on the plastic blocks were further processed for examination in the electron microscope. RESULTS: The electron microscopical examination showed that the secretory machinery was similar in both types of tissue. Thus, in both benign and well-differentiated neoplastic cells studied, the formation of storage vesicles in the Golgi areas was similar, the content of the vesicles appeared similar, the structure and distribution of prostasomes were alike, and in both benign and malignant tissue, the secretion in the gland ducts showed the same appearance with many prostasomes. CONCLUSION: We conclude that cells in benign prostate tissue and cells in well-differentiated prostate carcinoma show great similarities in synthesis, storage, and release of prostasomes. However, this does not exclude the presence of other changes, for instance biochemical ones, in the prostasomes.

Adenocarcinoma↗