Proliferating cell nuclear antigen/cyclin in incidental carcinoma of the prostate

Dimensional study of prostate cancer using stereological tools

This study analyzes the dimensional changes of the glands from prostate cancer by applying stereology to estimate the variations in volume, length, surface, and cellular densities of tumor acini. Normal and tumor acini were visualized using immunohistochemistry for cytokeratin18. On immunostained sections, parameters related to the dimensions and cell population of prostate acini were measured. The immunohistochemical expression of proliferative cell nuclear antigen was also measured to correlate the quantitative changes estimated with the proliferative activity of the epithelium. The average cell volume in normal and tumor epithelium was estimated using the method of the nucleator. The relative size of the acini was similar in the carcinoma compared with the normal prostate. Within the acini, the fraction of acinar volume occupied by the epithelium was significantly higher in cancer than in the nontumor prostate. Conversely, the glandular lumen of the cancer acini is lower than in the normal acini. The significant increase of acinar length density in the carcinoma indicates that the glandular tree's growth in the carcinoma is higher and with more branches than in the case of nonneoplastic glands. The basal surface density is higher in the carcinoma than in the controls. The number of epithelial cells per unit length of acini was significantly decreased in the neoplastic glands. This "dilution" of the cell population along the cancer acinus can be explained by the significant increase in the tumor cell's mean cell volume.

Human prostate cancer risk factors

Prostate cancer has the highest prevalence of any nonskin cancer in the human body, with similar likelihood of neoplastic foci found within the prostates of men around the world regardless of diet, occupation, lifestyle, or other factors. Essentially all men with circulating androgens will develop microscopic prostate cancer if they live long enough. This review is a contemporary and comprehensive, literature-based analysis of the putative risk factors for human prostate cancer, and the results were presented at a multidisciplinary consensus conference held in Crystal City, Virginia, in the fall of 2002. The objectives were to evaluate known environmental factors and mechanisms of prostatic carcinogenesis and to identify existing data gaps and future research needs. The review is divided into four sections, including 1) epidemiology (endogenous factors [family history, hormones, race, aging and oxidative stress] and exogenous factors [diet, environmental agents, occupation and other factors, including lifestyle factors]); 2) animal and cell culture models for prediction of human risk (rodent models, transgenic models, mouse reconstitution models, severe combined immunodeficiency syndrome mouse models, canine models, xenograft models, and cell culture models); 3) biomarkers in prostate cancer, most of which have been tested only as predictive factors for patient outcome after treatment rather than as risk factors; and 4) genotoxic and nongenotoxic mechanisms of carcinogenesis. The authors conclude that most of the data regarding risk relies, of necessity, on epidemiologic studies, but animal and cell culture models offer promise in confirming some important findings. The current understanding of biomarkers of disease and risk factors is limited. An understanding of the risk factors for prostate cancer has practical importance for public health research and policy, genetic and nutritional education and chemoprevention, and prevention strategies.

Histological markers of risk and the role of high-grade prostatic intraepithelial neoplasia

The marked discrepancy between the prevalence of preclinical prostate cancer and the incidence of clinically manifest disease indicates a long latency phase and significant heterogeneity in the progression potential of early neoplastic lesions. There are a variety of histologic changes within prostatic epithelium that have been termed atypical or dysplastic. The 2 most widely studied of these lesions are prostatic intraepithelial neoplasia (PIN) and atypical adenomatous hyperplasia (AAH). Although associations between AAH and adenocarcinoma are spurious, those linking high-grade PIN (HGPIN) to cancer are far more established. There is a significantly increased risk for patients with isolated HGPIN to have prostate cancer confirmed on subsequent biopsy, suggesting that HGPIN is a marker for prostate carcinoma in addition to its potential role as a premalignant lesion. Autopsy studies reveal that HGPIN is found in association with cancer in 63% to 94% of malignant and 25% to 43% of benign prostates. Data on age and race reveal that African American men develop more extensive HGPIN at a younger age than white men. A wide spectrum of molecular/genetic abnormalities appears to be common to both HGPIN and prostate cancer. Data loss of 8p, 10q, 16q, 18q, and gain of 7q31, 8q, multiple copies of the c-myc genes, along with changes in chromatin texture, telomerase activity, cell cycle status, and proliferative indices collectively suggest that HGPIN is intermediate between benign epithelium and prostatic carcinoma with respect to these markers. These data indicate that HGPIN is important in neoplastic progression, and may present an appropriate target/marker for chemoprevention.

p120 and AgNOR nucleolar protein expression: a comparison with nuclear proliferation markers in oral pathology

To find a better method for predicting the biological behavior of certain oral cavity lesions, the expression of nucleolar protein p120 and nucleolar organizer region counts (AgNOR) was compared with that of nuclear proliferation markers MIB-1 and PCNA in 10 cases of keratotic epithelial hyperplasia (KEH), 10 cases of epithelial dysplasia (ED), and 15 cases of squamous cell carcinoma (SCC). Significant differences in p120 and AgNOR mean area values and PCNA labeling index (LI) were recorded between KEH and ED, as well as ED and SCC (Student-Neumann-Keuls test). All markers significantly differed between SCC grades I and III. Significant differences were also noted in AgNOR mean area values between grade I and II SCC and in p120 mean area values. MIB-1 and PCNA LI differed significantly when grade II and III SCC were compared (SNK test). There were significant correlations between p120 and AgNOR (Pearson correlation coefficients) and between both of them and the proliferative indexes. AgNOR correlated with tumor grade, stage, and lymph node status (Spearman correlation coefficients), suggesting a prognostic role for that marker.

Cell kinetic studies on prostatic intraepithelial neoplasia (PIN) and atypical adenomatous hyperplasia (AAH) of the prostate

To investigate possible cell kinetic relations between benign prostatic hyperplasia (BPH), atypical adenomatous hyperplasia (AAH), prostatic intraepithelial neoplasia (PIN) and carcinoma, cell kinetic analyses were performed using radiolabelled DNA-precursors (3H-thymidine autoradiography), immunohistochemistry (proliferation marker Ki67/MIB1 and/or PCNA) and silver staining of nucleolar organizer regions (AgNOR). All methods yielded the lowest values for BPH and AAH, while maximal values were found in carcinoma of high malignancy. PIN was equal to GII-carcinomas, while AAH was between BPH and carcinoma of low malignancy. This investigation ranks BPH, AAH, low grade carcinoma, PIN and high grade carcinoma in order using different methods of cell kinetic analysis. The preneoplastic character of PIN is apparent whereas the character of AAH remains uncertain.

Nucleolar and AgNOR-analysis of prostatic intraepithelial neoplasia (PIN), atypical adenomatous hyperplasia (AAH) and prostatic carcinoma

Atypical glandular proliferations of the prostate are found in combination with prostate carcinomas but also with benign prostatic hyperplasia (BPH). These atypical glandular lesions that mimic glandular carcinoma within the anterocentral part of the prostate (transition zone) are named "atypical adenomatous hyperplasia (AAH)." The term for atypical ductal and acinar mainly papillary and/or cribriform proliferations in the peripheral zone is "prostatic intraepithelial neoplasia (PIN)." In this study the significance of the status of nucleoli and the number of silver-stained nucleolar organizing regions (AgNOR) as a method for measuring proliferative activity was investigated in biopsies of AAH, PIN and carcinomas of different grades of malignancy. The aim was to prove whether there are relationships of AAH to low grade carcinomas on the one hand and of PIN to high grade carcinomas on the other hand. The frequency of nuclei with small nucleoli was low in BPH (0.6%). The values increased to 8.3% in AAH, and 28.7% in PIN. The frequency of nuclei with prominent nucleoli in low grade carcinomas was 41.7% and in high grade carcinomas 81.1%. Usually, one single nucleolus was found per nucleus. Multiple prominent nucleoli were found in high grade carcinomas and in some cases of high grade PIN only. The result of AgNOR-analysis was similar: low numbers in BPH, low to moderate values in AAH, moderate values in low grade carcinomas and high values in PIN, as well as high grade carcinomas. Besides correlation between topography, histology and cytology, the similarities of nucleolar and AgNOR-analysis between PIN and high grade carcinomas support the idea that PIN is the precursor of the peripheral prostatic carcinoma. The histological, cytological and cell kinetical features of AAH are intermediate between BPH and low grade carcinoma of the prostate. Therefore, the findings to date are inconclusive and further follow up studies are necessary to prove if AAH may be a precursor of transition zone carcinoma of the prostate.