Prognostic significance of nuclear morphometry in renal cell carcinoma

Association between Nuclear Morphometry Parameters and Gleason Grade in Patients with Prostatic Cancer

Objective: Gleason scoring system remains the pathological method of choice for prostate cancer (Pca) grading. However, this method of tumor tissue architectural structure grading is still affected by subjective assessment and might succumb to several disadvantages, mainly inter-observer variability. These limitations might be diminished by determining characteristic cellular heterogeneity parameters which might improve Gleason scoring homogeneity. One of the quantitative tools of tumor assessment is the morphometric characterization of tumor cell nuclei. We aimed to test the relationship between various morphometric measures and the Gleason score assigned to different prostate cancer samples. Materials and Methods: We reviewed 60 prostate biopsy samples performed at a tertiary uro-oncology center. Each slide was assigned a Gleason grade according to the International Society of Urological Pathology contemporary grading system by a single experienced uro-pathologist. Samples were assigned into groups from grades 3 to 5. Next, the samples were digitally scanned (×400 magnification) and sampled on a computer using Image-Pro-Plus software©. Manual segmentation of approximately 100 selected tumor cells per sample was performed, and a computerized measurement of 54 predetermined morphometric properties of each cell nuclei was recorded. These characteristics were used to compare the pathological group grades assigned to each specimen. Results: Initially, of the 54 morphometric parameters evaluated, 38 were predictive of Gleason grade (p < 0.05). On multivariate analysis, 7 independent parameters were found to be discriminative of different Pca grades: minimum radius shape, intensity—minimal gray level, intensity—maximal gray level, character—gray level (green), character—gray level (blue), chromatin color, fractal dimension, and chromatin texture. A formula to predict the presence of Gleason grade 3 vs. grades 4 or 5 was developed (97.2% sensitivity, 100% specificity). Discussion: The suggested morphometry method based on seven selected parameters is highly sensitive and specific in predicting Gleason score ≥ 4. Since discriminating Gleason score 3 from ≥4 is essential for proper treatment selection, this method might be beneficial in addition to standard pathological tissue analysis in reducing variability among pathologists.

[Prognostic factors in localised and regionally advanced renal cell carcinoma]

In the last 10 years, several factors have been identified to confer a prognostic effect on renal cancer outcome. Pathologic stage, nuclear and histologic grade are the most frecuent studied and the most important at this moment. We evaluated those factors and introduced some others, looking for new parameters that could be useful. 96 cases of non methastatic renal cell cancer were included in our study. We found that as was mentioned by other authors pathologic and Furhman stage are the stronger prognostic factors but the presence of palpable tumor, pain and weight lost had significance too.

Clinicopathologic Significance of Nuclear Grooves and Inclusions in Renal Cell Carcinoma: Image Database Construction and Quantitative Scoring

Context.—Nuclear grooves and inclusions are major features of cancer. However, the nuclear irregularities in renal cell carcinoma (RCC) have not yet been well characterized.

Objective.—To determine the clinicopathologic significance of nuclear grooves and inclusions in RCC.

Design.—The frequencies or scores of nuclear grooves and inclusions were compared with the histologic subtype, nuclear grade, and TNM stage, as well as overall survival of RCC patients. For objective counting of nuclear irregularities, a relational image database was constructed and used for quantitative assessment.

Results.—Nuclear grooves and inclusions were seen in 96% and 65% of 110 RCC cases, respectively. The intranuclear inclusions were found more frequently in chromophobe and papillary types than in clear cell carcinoma (P &lt; .001). The nuclear scores, the sum of grooves or inclusions per 5000 tumor cells, were highly related to the histologic subtype (P &lt; .001). Clear cell RCCs with high inclusion scores (2 or more) were correlated with poorer overall survival in comparison to clear cell carcinomas with low inclusion scores (P = .04). The groove scores were highly associated with Fuhrman grade (P = .003) but not with overall survival of clear cell RCC patients (P = .65). In multivariate analysis, higher inclusion scores and advanced tumor stages (III/IV) were correlated with worse outcomes of clear cell RCC.

Conclusions.—Nuclear grooves and inclusions are histologic components of RCCs, especially chromophobe and papillary carcinomas. Furthermore, nuclear inclusions might be an independent prognostic factor for clear cell RCC.

Classical pathology versus molecular pathology in renal cell carcinoma

Renal cell carcinoma (RCC) has been characterized based on histology, stage, and grading to predict behavior and guide therapy; however, RCC is still unpredictable, with poor prognosis in metastatic disease. The classification of RCC has been revised to account for molecular characteristics, and there has been an increasing understanding of the hereditary forms of RCC. This has led to further elucidation of pathways in the development of RCC including the hypoxia-inducible pathway and angiogenesis. Many other promising molecular modalities are in development, including gene expression profiling, nuclear parameters, and proliferation/apoptotic markers. This article discusses the current understanding of the classical pathologic features of RCC and highlights recent developments in the cellular and molecular characterization of RCC, which aim to improve the classification, prognostication, and treatment of RCC.

Grading Systems in Renal Cell Carcinoma

PURPOSE

We reviewed updated literature data concerning several issues of renal cell carcinoma grading systems.

MATERIALS AND METHODS

We performed a nonsystematic review of the literature. Data were identified by a MEDLINE search using a strategy including MeSH and free text protocols. From the MEDLINE search we collected 184 records.

RESULTS

Although the original study was published in 1982, the independent predictive value of nuclear grades was only revealed in 2000 by the team from University of California-Los Angeles. Subsequently further data from our group and the group at the Mayo Clinic reconfirmed those findings, although similar cancer specific survival probabilities were noted among different grades. The prognostic relevance of nuclear grade justified the inclusion of that variable in algorithms and nomograms predictive of cancer specific survival, such as those provided by University of California-Los Angeles, the Mayo Clinic and Memorial Sloan-Kettering Cancer Center. Despite the routine clinical use of nuclear grade, several drawbacks have affected grading systems, such as interobserver and intra-observer reproducibility, and variability of the cancer specific survival probabilities stratified by grade. Several studies showed that intra-observer and interobserver agreement with regard to grade are only moderate with up shifting in all series. That issue might be due to the heterogeneity of renal cell carcinoma as well as to the lack of consensus about the minimal size of high grade tumor to be considered significant. Moreover, recent data underscore the role of histological subtypes.

CONCLUSIONS

Grade is one of the most powerful prognostic factors in patients with renal cell carcinoma. The Fuhrman grading system is currently most widely used by pathologists in Europe and the United States. However, there is still a need for better standardization of nuclear criteria to improve interobserver reproducibility and a major consensus should be achieved by uropathologists.

Renal cell carcinoma: relevance of pathology

PURPOSE OF REVIEW

Although pathological findings including tumour grade and tumour-node-metastasis stage provide prognostic information, the outcome for patients with renal cell carcinoma is occasionally unpredictable. Many studies have been undertaken to improve prediction of the prognosis of renal cell carcinoma, along with efforts to clarify the pathogenesis of renal cell carcinoma at the molecular level. This article reviews the advances in renal cell carcinoma research relevant to pathology published between 1 May 2002 and 30 April 2003.

RECENT FINDINGS

The establishment of a strict tumour grading system or adding microscopic venous invasion or tumour necrosis is potentially useful for predicting patient outcomes. The contribution of the von Hippel-Lindau-related pathway in early carcinogenesis has been partly revealed with regard to angiogenesis and cell cycle control. Tumour development in renal cell carcinoma can be considered as accumulating heterogenous molecular events related to cytokine production, cell cycle control, anti-apoptotic signal machinery and angiogenesis.

SUMMARY

Finding the target genes related to the von Hippel-Lindau pathway may explain the resistance of chemotherapy, and also provide a clue to finding a novel therapeutic option. Molecular targeting therapy can be applicable after more general molecules leading to tumour development and the metastasis of renal cell carcinoma have been identified.

Renal cell carcinoma: new prognostic factors?

PURPOSE OF REVIEW

There are limited independent predictors of survival in patients with renal cell carcinoma. Factors related to the tumor, host and treatment may help us to predict prognosis to a certain extent. Prognostic indicators would enable selection of patients who can benefit from adjuvant therapy and thus should be enrolled in clinical trials. This review highlights developments in the identification of current prognosticators for patients with renal cell carcinoma.

RECENT FINDINGS

Tumor stage, grade and patient-performance status are the known prognostic indicators in renal cell carcinoma. Besides these parameters, many molecular and cytogenetic markers were evaluated recently. Unfortunately, none of these parameters appear to be a better predictive prognostic factor than the usual staging and grading. Therefore, efforts to identify new markers for tumor proliferation and progression are still ongoing. It was recently reported that low carbonic anhydrase 9 staining may be an independent poor prognostic factor in patients with renal cell carcinoma. Moreover, there is increasing interest in prognostic indices and predictive algorithms for survival. Staging systems that combine the pathological features with additional prognostic variables have been constructed to predict outcome. The UCLA Integrated Staging System seems to be superior to staging alone in differentiating patients' survival.

SUMMARY

Although the literature reviewed contains numerous promising clinical, histological, molecular and cytogenetic parameters, none of them has yet been shown to have an independent prognostic value