Prognostic Criteria in Patients with Prostate Cancer: Correlation with Volume Weighted Mean Nuclear Volume

The use of design-based stereology to evaluate volumes and numbers in the liver: a review with practical guidelines

Stereology offers a number of tools for the analysis of sections in microscopy (which usually provide only two-dimensional information) for the purpose of estimating geometric quantities, such as volume, surface area, length or number of particles (cells or other structures). The use of these tools enables recovery of the three-dimensional information that is inherent in biological tissues. This review uses the liver as a paradigm for summarizing the most commonly used state-of-the-art methods for quantitation in design-based stereology. Because it is often relevant to distinguish hyperplasia and hypertrophy in liver responses, we also focus on potential pitfalls in the sampling and processing of liver specimens for stereological purposes, and assess the existing methods for volume and number estimation. With respect to volume, we considered whole liver volume (V), volume density (V(V)) and so-called local volumes, including the number-weighted volume (V(N)) and the volume-weighted volume (V(V)). For number, we considered the total number (N) and the numerical density (N(V)). If correctly applied, current stereological methods guarantee that no bias is introduced in the estimates, which will be therefore accurate; additionally, methods can be tuned for obtaining precise quantitative estimates that can reveal subtle changes in the volume or number of selected hepatic cells. These methods have already detailed the effects of some substances and specific diets on the liver, and should be routinely included in the toolbox of liver research.

Immunohistochemical study of cell proliferation, Bcl-2, p53, and caspase-3 expression on preneoplastic changes induced by cadmium and zinc chloride in the ventral rat prostate

This work was directed to evaluate immunoexpression of markers for apoptosis, resistance to apoptosis, and cell proliferation, as well as estimates of nuclear size in ventral prostate of rats treated with cadmium chloride and cadmium+zinc chloride because a possible protective effect of zinc has been postulated. The following variables were studied: volume fraction (VF) of Bcl-2 immunostaining, percentage of cells immunoreactive to proliferating cell nuclear antigen (LIPCNA) and p53 (LIp53), numerical density of caspase-3 immunoreactive cells (NV caspase-3), and estimates of volume-weighted mean nuclear volume (upsilonV). The LIPCNA and VF of Bcl-2 were significantly increased in the treated animals. The dysplasias (independent of their origin) showed a significant increase of the LIp53, NV caspase-3, and upsilonV in comparison with normal acini from treated and control animals. It can be concluded that cell proliferation is enhanced in long-term cadmium-exposed rats, and exposure to zinc combined with cadmium had no effect on any of the variables studied when comparing with normal acini. The increase of nuclear upsilonV could indicate a more aggressive behavior for pretumoral lesions.

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.

Imaging prostate cancer

In the detection of prostate cancer, the most important role of imaging is ultrasound-guided prostatic biopsy. In the staging evaluation of prostate cancer, each presently used modality--transrectal US (TRUS), MR imaging, CT, nuclear medicine, and positron emission tomography--has advantages and disadvantages. Evidence-based guidelines on the use of CT and nuclear medicine bone scan, in assessing the risk of distant spread of prostate cancer, are available. There is no consensus and there are no guidelines, however, for the use of imaging in the evaluation of prostate cancer local tumor extent. Results on the value of TRUS vary widely, and prospective multicenter studies suggest that TRUS is no better than digital rectal examination in predicting extracapsular extension. MR imaging offers the most promise for local staging of prostate cancer, but it must resolve problems of reproducible image quality and interobserver variability, and it should prove its efficacy in multicenter trials before it can be recommended for general clinical use. The introduction of MR spectroscopic imaging further expands the value of MR imaging, offering anatomic and metabolic evaluation of prostate cancer.

The role of volume-weighted mean nuclear volume in predicting disease outcome in patients with prostate cancer treated with radical prostatectomy

BACKGROUND

Estimates of volume-weighted mean nuclear volume (MNV) are the only means by which unbiased estimates of three-dimensional parameters can be obtained from single two-dimensional sections without any assumptions. We have reported that for prostate cancer estimates of MNV are prognostically equal or superior to morphological grading of malignancy, such as Gleason score (GS), and in particular, that MNV proved to be a meaningful predictor of prognosis for patients with clinically localized tumors. However, all previous studies were conducted on patients treated conservatively, and no authors have tested whether estimates of MNV can predict the prognosis of patients treated with radical prostatectomy.

MATERIALS AND METHODS

A retrospective prognostic study of 52 patients with clinically localized prostate cancer diagnosed at three Hospitals in Shizuoka Prefecture, Japan (Shizuoka City Hospital, Shizuoka Prefectural Hospital and Shimada Municipal Hospital) and treated by radical prostatectomy was performed. Twenty of these patients were treated with hormone therapy before radical prostatectomy. Unbiased estimates of MNV were compared with clinical stage, histological grading according to GS and neo-adjuvant hormone therapy with regard to the prognostic value.

RESULTS

MNV was significantly correlated with pathological T stage, but was not significantly correlated with the presence or absence of lymph node metastasis. Univariate analysis revealed that MNV correlated significantly with progression-free survival (p = 0.0116). Multivariate analysis revealed that MNV (p = 0.0115) and GS (p = 0.0275) were two significant independent predictors of progression-free survival.

CONCLUSIONS

The results of the present study suggest that MNV and GS are powerful independent predictors of prognosis for prostate cancer treated with radical prostatectomy. We recommend estimates of MNV as a supportive method to the histological grading for patients with prostate cancer.

Prognostic value of sarcomatoid histology and volume-weighted mean nuclear volume in renal cell carcinoma

OBJECTIVE

To determine the prognostic value of two histopathological factors, sarcomatoid histology and volume-weighted mean nuclear volume (MNV) in renal cell carcinoma (RCC).

PATIENTS AND METHODS

The study included 106 patients (72 men and 34 women, mean age 63 years, range 32-83) with RCC, all of whom were surgically treated between 1985 and 1995. The presence of any sarcomatoid component was determined and MNV estimated using a stereological method in histological slides of tumour specimens from these patients. The prognostic significance of the two variables was evaluated by univariate and multivariate analyses in comparison with other histopathological variables (T, N and M categories, nuclear grade, tumour size, tumour type), using the cause-specific and progression-free survival of the patients as the endpoints.

RESULTS

Among the 106 RCC cases examined, a sarcomatoid component was detected in 34 (32%); the MNV was 90-627 micro3 (mean 225). By univariate and multivariate analysis, both variables were significant prognostic factors for cause-specific survival in all patients. In addition, multivariate analysis of the 74 patients with localized RCCs (T1-3, N0 M0) showed that sarcomatoid histology was a significant prognostic factor for disease progression.

CONCLUSION

The presence of sarcomatoid histology and the MNV, both of which can be examined with no specialized laboratory procedures, seem to be useful tumour-related prognostic factors in RCC.

Combining volume-weighted mean nuclear volume with Gleason score and clinical stage to predict more reliably disease outcome of patients with prostate cancer

BACKGROUND

Various criteria for patients with prostate cancer have been reported to be of prognostic value, and we have reported that estimates of volume-weighted mean nuclear volume (MNV), developed by Gundersen and Jensen based on a stereological technique, accurately predict the prognosis of prostate cancer. However, all of these studies were conducted on cases in a single institution, and it has remained unclear whether MNV calculations obtained at one institution apply to cases at another institution. In attempting to solve this problem, we made a prognostic index (P.I.) based on data from one hospital, and tested whether these data could be used to predict the prognosis of patients at another hospital.

MATERIALS AND METHODS

A retrospective, multivariate prognostic study of 195 patients with prostate cancer, diagnosed at Kyoto University Hospital and treated conservatively, indicated that clinical stage, Gleason score, and MNV were all significantly correlated with the prognosis of patients with prostate cancer. From the relative strengths of these prognostic factors in a multivariate analysis, the following P.I. was constructed: P.I. = Clinical stage x 1.8040 + Gleason score x 1.5245 + MNV x 2.3162 (the constants correspond to the risk ratio estimated by Cox analysis). The P.I. was calculated for 104 patients with prostate cancer diagnosed at Shizuoka City Hospital and treated conservatively for analysis of disease-specific survival.

RESULTS

The prognostic index ranged from 3.841-16.142. Using the median value of 12.5 as a cutoff point, a clear separation of cases with poor and favorable prognosis was achieved (P < 0.0001, observation period: 1-167 months).

CONCLUSIONS

The results of this study suggest that estimates of MNV can be evaluated at multiple institutions with the use of P.I. calculation. Furthermore, combining estimates of MNV with Gleason score and clinical stage predicts most powerfully disease outcome of patients with prostate cancer.

Volume-weighted mean nuclear volume in renal cell carcinoma

OBJECTIVES

Tumor grade and stage are the most important prognostic parameters for renal cell carcinoma (RCC). The value of histologic nuclear grading, however, is impaired by the inconsistency of pathologists' observations. Estimate of volume-weighted mean nuclear volume (MNV), based on a stereologic method, is correlated with prognosis of bladder, prostate, and endometrial cancer. In this study, we investigated the prognostic value of stereologic estimation of nuclear volume in RCC.

METHODS

This study included 62 patients with RCC who underwent radical nephrectomy between 1989 and 1996. Patients were evaluated in two groups: patients with locally advanced and/or metastatic disease were part of the poor prognosis group and patients with localized disease were part of the good prognosis group. Unbiased estimates of MNV were compared with histologic grade, tumor stage, and growth pattern according to Thoenes classification. Group means were compared using the nonparametric Kruskal-Wallis one-way analysis of variance. Univariate analysis of the data was performed for MNV and time to death, metastasis, local recurrence, and disease-free survival by paired sample t test. For categorical variables, Pearson's correlation test was used for statistical analysis.

RESULTS

There was no correlation between MNV and patient sex, age, tumor stage, and growth pattern. MNV showed a trend to be higher in sarcomatoid and chromophilic cell types than in chromophobe and clear cell types (P < 0.05). MNV values were significantly higher with increasing grades but no MNV cutoff levels could be defined. The MNV values were not different between localized and locally advanced and/or metastatic disease.

CONCLUSIONS

Our results indicate that estimates of MNV are not useful for predicting disease outcome. Further studies are needed to set up reproducible intervals of tumor dedifferentiation that could be carried out in routine practice for predicting progression.

Histologic characteristics of renal cell carcinomas with lymph node metastasis

BACKGROUND

This study was conducted to determine if there are any specific histologic features that are associated with lymph node metastasis in renal cell carcinoma (RCC).

METHODS

TNM classification, histologic grade, mean nuclear volume, cell type, and histologic architecture of the tumors were evaluated in 66 patients who had undergone nephrectomy and lymphadenectomy for RCC. In the 18 patients with positive lymph node metastasis, both primary lesions and metastatic lymph nodes were evaluated.

RESULTS

Lymph node status was correlated with primary tumor stage, venous involvement, and distant metastasis. The tumor grade was higher, and the mean nuclear volume was larger, in both primary and metastatic lesions of RCCs with lymph node metastasis than in tumors with no metastasis. In primary lesions of RCCs with lymph node metastasis, clear cell, alveolar, or cystic patterns were observed less frequently, and granular or spindle/pleomorphic cells and papillary or solid patterns, were observed more frequently, as compared to those lesions without metastasis. Comparison between primary and metastatic lesions in individual patients revealed no significant difference in grade or mean nuclear volume. The development of new cell types or histologic architectures, which was not noted in the primary lesions, was also a rare event in the metastatic lesions.

CONCLUSION

Several characteristic histologic features, which may reflect the increased metastatic potential of the tumor, were observed in both primary and metastatic lesions in cases of RCC with lymph node metastasis. No substantial difference in histologic features was observed between the primary or metastatic lesions of individual patients.

Intratumoral heterogeneity in prostate cancer demonstrated by volume-weighted mean nuclear volume

This study was conducted to investigate the degree of heterogeneity of the volume-weighted mean nuclear volume (MNV) calculated from radical prostatectomy specimens, and to evaluate how closely the MNV calculated from transrectal biopsy specimens reflected the overall malignancy. MNV was evaluated using 77 sections of histological specimens from 9 patients who underwent radical prostatectomy at Shizuoka City Hospital between January 1990 and December 1995. The MNV values calculated from radical prostatectomy specimens were compared with those calculated from preoperative transrectal biopsy specimens. MNV was judged to be homogeneous in six cases and heterogeneous in three cases. Of the heterogeneous cases, MNV calculated from the transrectal biopsy specimens was judged to be underestimated in 2 of 3 cases. This study shows that intratumoral heterogeneity of prostate cancer may affect clinical estimates of the grade of malignancy based on the MNV, and indicates the need for a sufficient number of specimens in order to evaluate the MNV by transrectal biopsy.