Incidental carcinoma of the prostate: clinicopathological, stereological and immunohistochemical findings studied with logistic regression and self-organizing feature maps

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.

Stereological evaluation of the volume and volume fraction of newborns' brain compartment and brain in magnetic resonance images

PURPOSE

Brain development in early life is thought to be critical period in neurodevelopmental disorder. Knowledge relating to this period is currently quite limited. This study aimed to evaluate the volume relation of total brain (TB), cerebrum, cerebellum and bulbus+pons by the use of Archimedes' principle and stereological (point-counting) method and after that to compare these approaches with each other in newborns.

METHODS

This study was carried out on five newborn cadavers mean weighing 2.220 ± 1.056 g with no signs of neuropathology. The mean (±SD) age of the subjects was 39.7 (±1.5) weeks. The volume and volume fraction of the total brain, cerebrum, cerebellum and bulbus+pons were determined on magnetic resonance (MR) images using the point-counting approach of stereological methods and by the use of fluid displacement technique.

RESULTS

The mean (±SD) TB, cerebrum, cerebellum and bulbus+pons volumes by fluid displacement were 271.48 ± 78.3, 256.6 ± 71.8, 12.16 ± 6.1 and 2.72 ± 1.6 cm3, respectively. By the Cavalieri principle (point-counting) using sagittal MRIs, they were 262.01 ± 74.9, 248.11 ± 68.03, 11.68 ± 6.1 and 2.21 ± 1.13 cm3, respectively. The mean (± SD) volumes by point-counting technique using axial MR images were 288.06 ± 88.5, 275.2 ± 83.1, 19.75 ± 5.3 and 2.11 ± 0.7 cm3, respectively. There were no differences between the fluid displacement and point-counting (using axial and sagittal images) for all structures (p > 0.05).

CONCLUSION

This study presents the basic data for studies relative to newborn's brain volume fractions according to two methods. Stereological (point-counting) estimation may be accepted a beneficial and new tool for neurological evaluation in vivo research of the brain. Based on these techniques we introduce here, the clinician may evaluate the growth of the brain in a more efficient and precise manner.

Prediction of Prognosis in Patients with Epidural Hematoma by a New Stereological Method

Epidural hematoma (EH) is a serious clinical event observed in 2% of head trauma patients. Studies regarding the effects of epidural hematoma volume (EHV) on prognosis are not sufficient. In this study, we applied the volume fraction approach of the stereological method to estimate the hematoma to brain volume fraction (HBVF), and investigated the relation between the HBVF and prognosis. Fifty-nine EH patients (46 male and 13 female subjects, with average age of 21 years) admitted to the emergency clinic were included. The HBVF was estimated on the printed films of cranial computed tomography scans. For this purpose, common point counting grids were superimposed over the scan frames. According to the clinical results, patients were divided into three groups as complete recovery (43), disability (8) and exitus (8). The HBVF was compared with the clinical results. HBVF was determined as 4.6% in the patients with recovery, 8.1% in disability, and 7.6% in exitus patients. The HBVF values were lowest in recovery patients, and the difference between the recovery and the other two groups was statistically significant (p=0.007). However, there was no statistically significant difference in HBVF between disability and exitus patients (p>0.05). In conclusion, the HBVF can be an important tool to determine prognosis, and it can be measured using the volume fraction approach of stereological methods as developed in the present study.

Prognostic Value of DNA Ploidy, bcl-2 and p53 in Localized Prostate Adenocarcinoma Incidentally Discovered at Transurethral Prostatectomy

PURPOSE

Discovery of prostatic adenocarcinoma limited to transurethral resection material generates a treatment dilemma. We investigated the usefulness of parameters shown to be associated with prognosis in prostate cancer (p53 and bcl-2 immuno-expression, DNA cell cycle analysis and Gleason score) to stratify these incidentally identified tumors to guide clinical decision making.

MATERIALS AND METHODS

Paraffin embedded tissues from transurethral prostate resection specimens containing T1a prostate adenocarcinoma from 44 patients who underwent resection between 1980 and 1990 were immunostained for p53 and bcl-2, and subjected to flow cytometry to determine DNA ploidy. Gleason score was determined by 2 pathologists independently. Statistical relationships among these 4 variables, tumor progression and cancer specific survival were analyzed.

RESULTS

Six of 44 patients in the study population had cancer progression. Time to clinical progression was 4.5 years (range 7 months to 11 years). Most tumors stained negative for p53 and bcl-2. Only 2 tumors studied were aneuploid and neither of these 2 patients had cancer progression. Only Gleason score was a significant predictor of cancer progression on univariate and multivariate Cox regression analysis (p = 0.045 and 0.046, respectively). No tumor characteristics correlated with time to disease progression, including p53 and bcl-2 immuno-expression, and Gleason score (p = 0.182, 0.563 and 0.346, respectively). Positive immunostaining for p53 and bcl-2 did not occur together in the same tumor in significant fashion (p = 0.334), nor did either significantly occur more with aneuploidy (p = 0.237 and 0.307 respectively).

CONCLUSIONS

For T1a prostate cancer incidentally detected on transurethral prostate resection p53 and bcl-2 immuno-expression, and DNA ploidy do not predict survival or disease progression.

Statistical analysis of reduced pair correlation functions of capillaries in the prostate gland

Blood capillaries are thread-like structures that may be considered as an example of a spatial fibre process in three dimensions. At light microscopy, the capillary profiles appear as a planar point process on sections. It has recently been shown that the observed pair correlation function g(r) of the centres of the fibre profiles on two-dimensional sections may be used to estimate the reduced pair correlation function of stationary and isotropic fibre processes in three dimensions. In the present study, we explored how this approach may be extended to statistical analysis of reduced g-functions of capillaries from multiple specimens of different groups and with replicated observations. The methods were applied to normal prostatic tissue compared with prostate cancer. Confidence intervals for the mean reduced g-functions of groups were estimated for fixed r-values parametrically using the t-distribution, and by bootstrap methods. Each estimated reduced g-function was furthermore characterized in terms of its first maximum and minimum. The mean length of capillaries per unit tissue volume was significantly higher in prostate cancer tissue than in normal prostate tissue. Significant differences between the mean reduced g-functions of malignant and benign lesions could be demonstrated for two domains of r-values. In general, bootstrap-based confidence intervals were slightly wider than parametrically estimated confidence intervals. Falsely negative lower bounds of the intervals, which sometimes arose using the parametric approach, could be avoided by the bootstrap method. Testing of group mean values for significant differences by the bootstrap method yielded more conservative results than multiple t-tests. The functional value of the first maximum of the reduced g-function and a global statistical parameter of short-range ordering was significantly reduced in the carcinoma group. Prostate cancer tissue is more densely supplied with capillaries than normal prostate tissue and the three-dimensional arrangement of the vessels differs with respect to interaction at various distance ranges. In the local approach used here, bootstrap methods can be used as a robust statistical tool for the computation of confidence intervals and group comparisons of mean reduced g-functions at specific ranges of interaction.

Energy balance alters dunning R3327-H prostate tumor architecture, androgen receptor expression, and nuclear morphometry in rats

BACKGROUND

We hypothesize that diet or energy restriction may alter prostate tumor architecture and nuclear morphometry in a manner predictive of indolent biology.

METHODS

Adult male rats bearing the Dunning R3327-H tumor were provided free-access to the AIN76 diet or 30% diet/energy restriction for 16 weeks. Tumor tissue was harvested and stained for biomarker evaluation by quantitative digital image analysis.

RESULTS

Compared to controls, tumors from restricted rats showed a contracted stromal compartment with an increased epithelial/glandular area, and a greater number of smaller and more homogeneous glands. In parallel, the nuclei in tumors harvested from diet-restricted rats were smaller in size, showed a lower proportion with androgen receptor (AR) staining, and reduced intensity of AR staining.

CONCLUSIONS

Our observations support the hypothesis that diet/energy restriction alters prostate tumor architecture, AR expression, and nuclear morphology consistent with a more differentiated and less aggressive phenotype.

Prediction of the axillary lymph node status in mammary cancer on the basis of clinicopathological data and flow cytometry

Axillary lymph node status is a major prognostic factor in mammary carcinoma. It is clinically desirable to predict the axillary lymph node status from data from the mammary cancer specimen. In the study, the axillary lymph node status, routine histological parameters and flow-cytometric data were retrospectively obtained from 1139 specimens of invasive mammary cancer. The ten variables: age, tumour type, tumour grade, tumour size, skin infiltration, lymphangiosis carcinomatosa, pT4 category, percentage of tumour cells in G2/M- and S-phases of the cell cycle, and ploidy index were considered as predictor variables, and the single variable lymph node metastasis pN (0 for pN0, or 1 for pN1 or pN2) was used as an output variable. A stepwise logistic regression analysis, with the axillary lymph node as a dependent variable, was used for feature selection. Only lymphangiosis carcinomatosa and tumour size proved to be significant as independent predictor variables; the other variables were non-contributory. Three paradigms with supervised learning rules (multilayer perceptron, learning vector quantisation and support vector machines) were used for the purpose of prediction. If any of these paradigms was used with the information from all ten input variables, 73% of cases could be correctly predicted, with specificity ranging from 82 to 84% and sensitivity ranging from 60 to 63%. If only the two significant input variables were used, lymphangiosis carcinomatosa and tumour diameter, the prediction accuracy was no worse. Nearly identical results were obtained by two different techniques of cross-validation (leave-one-out against ten-fold cross validation). It was concluded that: artificial neural networks can be used for risk stratification on the basis of routine data in individual cases of mammary cancer; and lymphangiosis carcinomatosa and tumour size are independent predictors of axillary lymph node metastasis in mammary cancer.