Renal cell carcinoma. A clinicopathologic and DNA flow cytometric analysis of 103 cases

A non-diploid DNA status is linked to poor prognosis in renal cell cancer

Purpose

DNA ploidy measurement has earlier been suggested as a potentially powerful prognostic tool in many cancer types, but the role in renal tumors is still unclear.

Methods

To clarify its prognostic impact, we analyzed the DNA content of 1320 kidney tumors, including clear cell, papillary and chromophobe renal cell carcinoma (RCC) as well as renal oncocytoma and compared these data with clinico-pathological parameters and patient prognosis.

Results

A non-diploid DNA content was seen in 37% of 1276 analyzable renal tumors with a striking predominance in chromophobe carcinoma (74.3% of 70 cases). In clear cell carcinoma, a non-diploid DNA content was significantly linked to high-grade (ISUP, Fuhrman, Thoenes; p < 0.0001 each), advanced tumor stage (p = 0.0011), distant metastasis (p < 0.0001), shortened overall survival (p = 0.0010), and earlier recurrence (p < 0.0001). In papillary carcinoma, an aberrant DNA content was significantly linked to high Fuhrman grade (p = 0.0063), distant metastasis (p = 0.0138), shortened overall survival (p = 0.0010), and earlier recurrence (p = 0.0003).

Conclusion

In summary, the results of our study identify a non-diploid DNA content as a predictor of an unfavorable prognosis in clear cell and papillary carcinoma.

Electronic supplementary material

The online version of this article (10.1007/s00345-020-03226-8) contains supplementary material, which is available to authorized users.

Prognostic Biomarkers in Renal Cell Carcinoma: Relevance of DNA Ploidy in Predicting Disease-Related Survival

Objective

To investigate the prognostic value of DNA ploidy, Ki-67 index and p53 expression in relation to disease-related survival in a consecutive series of patients with renal cell carcinoma (RCC).

Material and methods

The study group consisted of 64 RCC patients treated by radical nephrectomy. Histological type, pathological staging and nuclear anaplasia were assessed according to the WHO classification, TNM system and Fuhrman grading criteria, respectively. Ploidy was determined by DNA flow cytometry using two sampling methods (frozen vs paraffin-embedded tissue). Ki-67 and p53 were evaluated by immunohistochemistry techniques using two cutoff points (10% vs mean value) for staining interpretation. Kaplan-Meier and Cox regression analyses were used for prognostic evaluation.

Results

Thirty-one tumors (48.4%) showed DNA diploidy and 33 (51.6%) were DNA aneuploid. Concordance between both ploidy measurement methods was found in 85.5% of cases (p=0.0455). The mean values for Ki-67 and p53 immunostaining were 3.65% (0–23.5%) and 5.90% (0–55.9%), respectively. DNA ploidy significantly correlated with staging, tumor size (pT), nuclear grading, and Ki-67 (mean value cutoff). Ki-67 (10% cutoff) correlated with staging and pT, while p53 (mean value cutoff) was associated with Ki-67 (mean value cutoff). There were significant differences between survival curves for pathological stage, pT, nuclear grade, ploidy, Ki-67 (both cutoffs), and p53 (10% cutoff). By univariate regression analysis, stage III and stage IV, pT3, aneuploidy, high Ki-67 (both cutoffs), and p53 overexpression (10% cutoff) showed significant correlations with worse disease-related survival. In addition, DNA aneuploidy significantly correlated with poor prognosis within stages I/II (p=0.0355) and stages III/IV (p=0.0138) of the disease.

Conclusion

The results indicate that DNA ploidy has relevant prognostic value in RCC, adding useful information to the classic histopathological indicators of clinical outcome.

Clinicopathologic and DNA Flow Cytometric Analysis of Eighty-three Renal Cell Carcinomas

The clinical and anatomopathologic features as well as DNA content of 83 renal cell carcinomas were analyzed. The possible interrelationship and prognostic value of these factors were also considered. The DNA study has been performed by flow cytometry using paraffin-embedded tissues. In each case an internal control with nonneoplastic renal tissue obtained in the same nefrectomy was also done in order to calculate the DNA index. Differences in patient age, nuclear grade, and mitotic activity were related with outcome; however, this relationship was not confirmed by the Cox test. Stage (P = .005), cell type (P = .002), and metastatic disease (P = .001) had independent prognostic values. Renal cell carcinomas with low stage and with low S-phase had better prognosis. Int J Surg Pathol 3(1):1-8, 1995

18-F fluorodeoxyglucose uptake in positron emission tomography as a pathological grade predictor for renal clear cell carcinomas

OBJECTIVES

To evaluate the usefulness of Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18-F FDG-PET/CT) in the prediction of Fuhrman pathological grades of renal clear cell carcinoma (cRCC).

METHODS

This retrospective study was approved by our institutional review board, and written informed consent was waived. Thirty-one patients with pathologically proven cRCC underwent 18-F FDG-PET/CT for tumour staging. Maximum standardized uptake value of cRCC (tumour SUVmax) and mean SUV of the liver and spleen (liver and spleen SUVmean) were measured by two independent observers. Tumour SUVmax, tumour-to-liver SUV ratio, and tumour-to-spleen SUV ratio were correlated with the pathological grades.

RESULTS

Logistic analysis demonstrated that only the tumour-to-liver SUV ratio was a significant parameter for differentiating high-grade (Fuhrman grades 3 and 4) tumours from low-grade (Fuhrman grades 1 and 2) tumours (P = 0.007 and 0.010 for observers 1 and 2, respectively). Sensitivity, specificity, and positive and negative predictive values for detecting tumours of Fuhrman grades 3 and 4 were 64, 100, 100, and 77%, respectively, for observer 1, and 79, 88, 85, and 83%, respectively, for observer 2.

CONCLUSIONS

The tumour-to-liver SUV ratio with 18-F FDG-PET/CT appeared to be a valuable imaging biomarker in the prediction of high-grade cRCC.

KEY POINTS

• Tumour SUV max was correlated with the Fuhrman grades. • High-grade tumours have significantly higher SUV max than low-grade tumours. • Tumour-to-liver SUV ratio is useful in the prediction of high-grade cRCC.

Use of percutaneous radiofrequency ablation in pulmonary metastases from renal cell carcinoma

BACKGROUND

Surgical resection of pulmonary metastases from renal cell carcinoma (RCC) has been demonstrated in recent studies to produce good long-term survival outcomes. Radiofrequency ablation (RFA) may offer an alternative treatment option for this group of patients, especially for those who are unable to have surgery.

METHODS

Nine patients had a total of 23 pulmonary metastases treated with percutaneous RFA under fluoro-computed tomography (CT) guidance. Patients underwent routine overnight hospitalization and monitoring for other potential complications. CT scans were performed at 1 month after the procedure and at 3-monthly intervals.

RESULTS

A total of 25 ablations were performed to 23 pulmonary metastases for our nine patients in 12 RFA sessions. No patient died within 30 days of the procedure. Five of the 12 procedures resulted in a pneumothorax (42%) and 3 required insertion of a Pleurocath. One patient had a bronchopulmonary fistula with an associated small pleural effusion and one patient had pneumonia. Of the 25 ablations, 14 lesions had decreased in size (56%), 1 was stable in size (4%), and 9 had increased in size (36%). One patient had deceased before adequate follow-up. Of the nine patients, two are alive and free of disease (mean survival time of 74 months), two are alive with disease (mean survival time of 16 months), and five have died of disease (mean survival time of 26.2 months).

CONCLUSION

RFA offers a treatment alternative for local tumor control, particularly in selected patients with multiple, small lesions who are unsuitable for pulmonary resections.

Grade-dependent proteomics characterization of kidney cancer

Kidney cancer is frequently metastatic on presentation at which point the disease is associated with a 95% mortality. Assessment of tumor grade on pathological examination is the most powerful means for prognostication as well as for stratification of patients into those who might respond to conventional or targeted therapy. Although there exist several grading systems in common use, all suffer from significant disparity among observers. In an attempt to objectify this process as well as to acquire grade-specific mechanistic information, we performed LC-MS/MS-based proteomics analysis on 50 clear cell kidney cancers equally distributed among normal tissues and Fuhrman grades 1-4. Initial experiments confirmed the utility of using archived formalin-fixed paraffin-embedded samples for LC-MS/MS-based proteomics analysis, and the LC-MS/MS findings were validated by extensive immunoblotting. We now show that changes among many biochemical processes and pathways are strongly grade-dependent with the glycolytic and amino acid synthetic pathways highly represented. In addition, proteins relating to acute phase and xenobiotic metabolism signaling are highly represented. Self-organized mapping of proteins with similar patterns of expression led to the creation of a heat map that will be useful in grade characterization as well as in future research relating to oncogenic mechanisms and targeted therapies for kidney cancer.

Percentage of high-grade carcinoma as a prognostic indicator in patients with renal cell carcinoma

BACKGROUND

The prognostic value of Fuhrman nuclear grade for patients with renal cell carcinoma has been well-characterized. However, to the authors' knowledge, the prognostic significance of the amount of high-grade renal cell carcinoma has not been previously analyzed.

METHODS

The authors identified 898 consecutive renal cell carcinoma cases treated with nephrectomy between 1989 and 2003. Histopathologic features that were captured based on re-review of all slides included histologic type, pathologic stage, conventional Fuhrman grade, and percentage of Fuhrman grade 3 and 4 carcinoma, as ascertained by visual inspection of histologic slides. The clinical endpoints were metastasis-free survival, cancer-specific survival, and overall survival.

RESULTS

Kaplan-Meier analysis demonstrated that both conventional Fuhrman grading and the percentage of Fuhrman grade 3 and 4 carcinoma were highly correlated with all 3 measures of patient survival (P < .0001). The creation of 3 categories of the percentage of Fuhrman grade 3 and 4 carcinoma (0%, 1-50%, and 51-100%) generated distinctly separate survival curves. On Cox proportional hazards multivariate analysis, TNM stage, tumor size, and the percentage of Fuhrman grade 3 and 4 carcinoma were all found to be significantly associated with all 3 types of patient survival (all P values <.05).

CONCLUSIONS

The determination of the percentage of renal cell carcinoma that is 0%, 1% to 50%, or 51% to 100% high Fuhrman grade 3 and 4 is a simple and powerful measurement of patient outcome after surgery that provides additional prognostic information beyond stage, tumor size, and conventional Fuhrman grade. This prognostic information could be useful in the stratification of patients into prognostic groups for the development of more individualized follow-upschedules and for enrollment into clinical trials.

Five-year survival after surgical treatment for kidney cancer: a population-based competing risk analysis

BACKGROUND

Kidney cancer's rising incidence is largely attributable to the increased detection of small renal masses. Although surgery rates have paralleled this incidence trend, mortality continues to rise, calling into question the necessity of surgery for all patients with renal masses. Using a population-based cohort, a competing risk analysis was performed to estimate patient survival after surgery for kidney cancer, as a function of patient age and tumor size at diagnosis.

METHODS

With data from the Surveillance, Epidemiology, and End Results Program (1983-2002), a cohort was assembled of 26,618 patients with surgically treated, local-regional kidney cancer. Patients were sorted into 20 age-tumor size categories and the numbers of patients that were alive, dead from kidney cancer, and dead from other causes were tabulated. Poisson regression models were fitted to obtain estimates of cancer-specific and competing-cause mortality.

RESULTS

Age-specific kidney cancer mortality was stable across all size strata but varied inversely with tumor size. Patients with the smallest tumors enjoyed the lowest cancer-specific mortality (5% for masses<or=4 cm). Competing-cause mortality rose with increasing patient age. The estimated 5-year competing-cause mortality for elderly subjects (>or=70 years) was 28.2% (95% confidence interval [CI]: 25.9%-30.8%), irrespective of tumor size.

CONCLUSIONS

Despite surgical therapy, competing-cause mortality for patients with renal masses rises with increasing patient age. After 5 years, one-third of elderly patients (>or=70 years) will die from other causes, suggesting the need for prospective studies to evaluate the role of active surveillance as an initial therapeutic approach for some small renal masses.

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.

Immunosuppressive acidic protein detects high nuclear grade localized renal cell carcinoma

OBJECTIVES

To identify a potentially useful preoperative predictor of high nuclear grade renal cell carcinoma (RCC).

METHODS

Our investigation consisted of 181 patients with histologically confirmed clear cell RCC. The positive predictive value, sensitivity, and specificity for detecting nuclear grade RCC were calculated individually for the largest tumor diameter. Hemoglobin, alkaline phosphatase, C-reactive protein, ferritin, and immunosuppressive acidic protein (IAP) levels were also determined in all patients preoperatively.

RESULTS

The distribution of patients by nuclear grade was 74 patients (41%) with grade 1, 75 (41%) with grade 2, and 32 (18%) with grades 3 and 4. With respect to sensitivity, tumor diameter detected 28 (87.5%) of 32 high nuclear grade RCC specimens, and hemoglobin, C-reactive protein, alkaline phosphatase, ferritin, and IAP detected 10 (31.2%), 25 (78.1%), 8 (25.0%), 16 (50%), and 27 (84.3%) of 32, respectively. Multiple logistic regression analysis showed that a higher than normal C-reactive protein and IAP was associated with a 252% and 405% increase in the odds of a high nuclear grade, respectively. In the Stage T1 cases, elevated IAP was also associated with a 989% increase in the odds of a high nuclear grade.

CONCLUSIONS

IAP level may be a useful predictor for detecting high nuclear grade localized RCC preoperatively.

Clear cell renal cell carcinoma

Clear cell RCC is the most common type of RCC that occurs in adults. It has the worst prognosis among the common epithelial tumors of the kidney. Histologically, a wide range of morphologic patterns can be encountered. Those cases with a multi-locular cystic architecture are considered to be a distinct subtype because of the clinicopathologic features.

A Review of Prognostic Pathologic Features and Algorithms for Patients Treated Surgically for Renal Cell Carcinoma

Accurate subtyping of RCC is critically important and should be considered in algorithms that are developed as prognostic tools for the patient and clinician. The TNM classification, already a powerful prognostic factor, will continue to evolve. The authors recommend that each component of the classification be assessed and reported during pathologic examination. This article also highlighted the importance of assigning a nuclear grade that is based on standardized and reproducible criteria that reflect the heterogeneity of nuclear and nucleolar features within RCC. Lastly, it is increasingly evident that coagulative tumor necrosis and sarcomatoid differentiation are compelling prognostic factors, on par with nuclear grade, and should be assessed routinely. To conclude, the complete list of pathologic features that are evaluated as part of the Mayo Clinic Nephrectomy Registry is presented. The features that are reported routinely in clinical practice also are indicated; this can serve as a guide for the reporting of results from the pathologic examination of RCC.

Levels of angiogenesis and expression of angiogenesis-related genes are prognostic for organ-specific metastasis of renal cell carcinoma

BACKGROUND

To identify organ-specific, metastasis-related factors that can be used to predict the development and location of metastasis of clear cell renal cell carcinoma (CRCC), the authors assessed the angiogenesis and the expression of angiogenesis-related genes in primary and metastatic tumors.

METHODS

They evaluated intratumoral microvessel density (MVD) by immunohistochemical staining, assessed the expression of angiogenesis-related genes by mRNA in situ hybridization, and determined the clinicopathologic characteristics of 92 archival specimens of primary and metastatic CRCCs from 54 patients. All 38 metastatic tumor specimens were resected from 24 patients.

RESULTS

The pathologic stage (P=0.026) of the primary tumor specimen was an important predictor for metastasis, as were MVD (P=0.000025) and the ratio of matrix metalloproteinases (MMPs) to E-cadherin (M/E ratio; P=0.000041). In addition, primary tumor specimens resected from patients with metastatic CRCCs had high MVD, high levels of MMP-2 expression, and a high M/E ratio (P <0.05). Relative to the primary tumors, the metastatic tumors also had high MVD, overexpression of basic fibroblast growth factor, vascular endothelial growth factor, interleukin-8, MMPs, and a high M/E ratio (P <0.05). Multivariate analysis revealed that MVD and the M/E ratio in the primary tumor were independent prognostic factors for metastasis (P=0.049 and P=0.001, respectively). Furthermore, the M/E ratio in metastatic tumor specimens resected from the lung and lymph node was an independent prognostic factor for metastasis (P=0.01823 and P=0.03950, respectively).

CONCLUSIONS

The current study indicated that angiogenesis and M/E ratio were specific predictors for metastases of RCC, especially to the lung or lymph node. Therefore, MMPs and E-cadherin could be relevant targets for novel therapeutic strategies to control or prevent the metastasis of RCC.

Multicenter determination of optimal interobserver agreement using the Fuhrman grading system for renal cell carcinoma: Assessment of 241 patients with > 15-year follow-up

BACKGROUND

The Fuhrman system is the most widely used nuclear grading system for renal cell carcinoma (RCC). Although Fuhrman nuclear grade is widely accepted as a significant prognostic factor, its reproducibility, as reported in the limited number of series available in the literature, appears to be low.

METHODS

Between 1980 and 1990, 255 cases of RCC (pT1-3bN0M0) were treated with radical nephrectomy at the Department of Urology, University Hospital, Strasbourg, France. In a retrospective multicenter study, 3 pathologists independently classified 241 of these 255 cases according to the Fuhrman grading system. The authors searched for optimal interobserver agreement by collapsing the grading system to a three-tiered scheme and then to a two-tiered scheme. In addition, overall survival curves were generated according to the classic four-tiered scheme and also according to the best collapsed scheme. The kappa index was used to assess the level of agreement between each pair of observers, and the Cox model was used for multivariate survival analyses.

RESULTS

The mean interobserver kappa value was 0.22 (range, 0.09-0.36). The best concordance was obtained by collapsing to a system in which low-grade (Grade 1-2) disease was compared with high-grade (Grade 3-4) disease. Doing so improved the mean interobserver kappa value to 0.44 (range, 0.32-0.55). Fuhrman grade was an independent prognostic factor for all 3 pathologists (P = 0.01, P < 0.0001, and P = 0.004, respectively), and nuclear grade continued to have independent prognostic value after the optimal collapsing algorithm was performed (P = 0.004, P = 0.0003, and P = 0.005).

CONCLUSIONS

Collapsing of the Fuhrman grading system to a two-tiered scheme led to an improvement in interobserver agreement while preserving the independent prognostic value of nuclear grade.

Prognostic value of uPA, PAI-1, and DNA content in adult renal cell carcinoma

OBJECTIVES

To examine whether urokinase-type plasminogen activator (uPA) and type 1 plasminogen inhibitor (PAI-1), DNA ploidy, and S-phase fraction (SPF) add supplementary prognostic information relative to stage and Fuhrman's grade in renal cell carcinoma.

METHODS

A total of 100 patients with primary renal adenocarcinoma treated by nephrectomy were followed up for a median of 42 months. Of the 100 patients, 78 with Stage M0N0-Nx tumors were studied by multivariate analysis. The study population was dichotomized on the basis of the median cytosolic uPA and PAI-1 concentrations (30 pg/mg protein and 12.7 ng/mg protein, respectively). DNA content was measured by flow cytometry (FCM) on multiple tumor samples from each patient. DNA aneuploidy was observed in 67% of cases. The SPF was calculated for aneuploid samples.

RESULTS

An FCM classification based on a combination of DNA content and SPF was obtained. High-risk patients were those with aneuploid tumors and high SPF values (greater than 1.7%) and included 23% of patients with M0N0-Nx tumors. Cytosolic uPA and PAI-1 levels were not predictive of metastasis. The stage, grade, SPF, and FCM classification were statistically significant prognostic factors in the univariate analysis, in both the overall population and the M0N0-Nx subgroup. In multivariate analysis, tumor grade and the FCM classification were the only independent predictors of disease-free survival (P = 0.018 and P = 0.046, respectively).

CONCLUSIONS

We defined a group of M0N0-Nx patients with aneuploid tumors and high SPF values who are at a high risk of metastasis and who may benefit from closer long-term follow-up.

Original and reviewed nuclear grading according to the Fuhrman system

BACKGROUND

The objective of the current study was to evaluate the reproducibility of the Fuhrman nuclear grading system as well as its independent predictive value in a series of patients with conventional renal cell carcinoma (RCC).

METHODS

The authors selected 388 patients who had undergone surgical treatment for conventional RCC between 1986 and 2000. Pathology slides from the selected patients were reviewed by a single pathologist, who reassigned a Fuhrman nuclear grade and assessed the presence of tumor necrosis. The pathologist was blinded to both the original pathologic diagnosis and follow-up data. The kappa statistic was used to evaluate concordance between original and reviewed nuclear grades. The log-rank test was used for univariate analyses, and a Cox proportional hazards model was used for multivariate analyses.

RESULTS

The original Fuhrman nuclear grade was Grade 1 (G1) in 111 patients (28.6%), G2 in 141 patients (36.3%), G3 in 108 patients (27.8%), and G4 in 28 patients (7.3%). After pathology slide review, nuclear grades were reassigned as follows: G1 in 49 patients (12.6%), G2 in 138 patients (35.6%), G3 in 150 patients (38.7%), and G4 in 51 patients (13.1%). The grade of concordance was moderate (kappa=0.44; P <0.001). Univariate analyses identified three separate prognostic categories defined by nuclear grade (G1 and G2 vs. G3 vs. G4). Both the original and the reviewed Fuhrman nuclear grading systems were capable of independently predicting disease-specific survival in patients with conventional RCC.

CONCLUSIONS

The interobserver reproducibility of Fuhrman nuclear grading was moderate. The substantial overlap in survival curves for G1 and G2 tumors provided an opportunity to cluster those categories, and the resulting three-tiered nuclear grading system was an independent predictor of cause-specific survival in patients with conventional RCC. Other independent predictors of survival included pathologic stage and tumor necrosis status.

Nephron-sparing surgery for renal cell carcinoma: clinicopathologic features predictive of patient outcome

OBJECTIVES

To determine the clinicopathologic features associated with outcome in patients with sporadic renal cell carcinoma (RCC) treated with nephron-sparing surgery.

METHODS

We studied 344 patients treated with nephron-sparing surgery between 1970 and 2000. The pathologic features of the tumors were reviewed by two urologic pathologists who recorded the histologic subtype, 2003 TNM stage, tumor size, and grade. Cancer-specific survival (CSS) was estimated using the Kaplan-Meier method, and log-rank tests were used to compare the outcome by histologic subtype. Univariate Cox proportional hazards models were fit to assess the associations between the clinicopathologic features and death from RCC, distant metastases, and local recurrence.

RESULTS

The CSS rate at 5 and 10 years for patients with clear cell RCC was 94.4% and 91.5%, respectively. In contrast, the CSS rate at 5 and 10 years for patients with papillary or chromophobe RCC was 99.0%, because only 1 patient died of papillary RCC and no patient died of chromophobe RCC (P = 0.029). Among the patients with localized clear cell RCC, tumor stage and grade were significantly associated with death from RCC and metastases. Grade was significantly associated with local recurrence for clear cell RCC, but not for papillary RCC.

CONCLUSIONS

In our series of patients with RCC treated with nephron-sparing surgery, patients with clear cell RCC had a significantly worse CSS than did patients with papillary and chromophobe RCC. Tumor stage and grade were associated with outcome among patients with localized clear cell RCC. These findings are similar to the results for patients with localized clear cell RCC treated with radical nephrectomy.

Current staging of renal cell carcinoma

Most (>80%) cancers involving the kidney are renal cell carcinoma (RCC). One third of patients diagnosed with kidney cancer have evidence of metastatic disease at the time of diagnosis, and as many as half of patients treated for localized disease eventually relapse. As is true for any other malignancy, one must determine which tumor features, patient factors, and laboratory techniques will provide diagnostic and prognostic information for patients with RCC. This article focuses on the history and rationale of the current staging systems for RCC as well as the potential for improvements by the addition of other clinical, pathologic, and molecular prognostic markers.

Interobserver and intraobserver variability using the Fuhrman grading system for renal cell carcinoma

CONTEXT

Histologic grading of renal cell carcinoma has been shown to be second to staging in prognostic significance. A 4-tier grading scheme proposed by Fuhrman et al and based on nuclear features is the system used most frequently in North America. There are, however, very few studies in the literature assessing the interobserver variability for this system, and to our knowledge, none addressing intraobserver variability.

OBJECTIVE

To assess the interobserver and intraobserver agreement among 4 pathologists using the Fuhrman nuclear grading scheme for renal cell carcinoma.

DESIGN

Representative hematoxylin-eosin-stained slides of 99 consecutive primary renal cell carcinoma cases diagnosed between 1994 and 1999 at St Joseph's Hospital, Hamilton, Ontario, were independently graded by 4 pathologists on 2 occasions with a minimum period of 3 months separating the 2 readings.

RESULTS

Intraobserver kappa values ranged from 0.29 to 0.62 (mean = 0.45), and interobserver kappa values ranged from 0.19 to 0.38 and from 0.09 to 0.44 for the first and second rounds, respectively (combined mean kappa value = 0.29). When combining Fuhrman grades 1 and 2 as low-grade tumors and grades 3 and 4 as high-grade tumors, the intraobserver kappa values ranged from 0.4 to 0.64 (mean = 0.53) and interobserver kappa values ranged from 0.28 to 0.59 and from 0.26 to 0.58 for the first and second rounds, respectively (combined mean kappa value = 0.45). The admixture of 2 grades in the same tumor was observed in 53% of cases.

CONCLUSIONS

We found only moderate intraobserver and interobserver agreement using the 4-grade Fuhrman scheme. After collapsing the diagnostic grades to 2, the intraobserver agreement changed from moderate to substantial. The collapsing of the 4-category Fuhrman grades into 2 categories is useful in improving intraobserver agreement.

Comparison of standardized and nonstandardized nuclear grade of renal cell carcinoma to predict outcome among 2,042 patients

We compared the ability of original nuclear grades from surgical pathology reports and grades reviewed by a urologic pathologist to predict death due to renal cell carcinoma (RCC) for 2,042 patients treated with radical nephrectomy between January 1970 and December 1998. Reviewed grade I tumors had small, round nuclei with inconspicuous nucleoli visible at x400; grade 2 contained round to slightly irregular nuclei with mildly enlarged nucleoli visible at x200; grade 3 had round to irregular nuclei with prominent nucleoli visible at x100; grade 4 contained enlarged pleomorphic or giant cells. Predictive abilities were compared using R2 values from Cox proportional hazards models. There were 1,733 (84.87%) clear cell, 222 (10.87%) papillary, and 87 (4.26%) chromophobe tumors. Reviewed grades were more predictive of death due to RCC than original grades for clear cell (R2, 21% vs 16%), papillary (R2, 16% vs 13%), and chromophobe (R2, 39% vs 27%) RCC. Among patients with clear cell and papillary RCC, this difference was apparent even after adjusting for the 1997 TNM stage. Standardized nuclear grades were more predictive of death due to RCC than nonstandardized grades for all subtypes studied.

Prognostic features of pathologic stage T1 renal cell carcinoma after radical nephrectomy

OBJECTIVES

To assess the effect of renal cell carcinoma (RCC) subtype, tumor size, and Fuhrman grade on clinical outcome in patients with pathologic T1 (pT1) RCC treated with radical nephrectomy.

METHODS

Between 1970 and 1998, 840 patients underwent radical nephrectomy for pT1 RCC. Tumors were subtyped and graded. Univariate and multivariate Cox proportional hazards models were fitted to assess the features associated with metastasis-free survival (MFS) and cancer-specific survival (CSS). We identified a range of tumor sizes of clear cell RCC in which a transition occurred from low to high risk. Cox proportional hazards models were then fitted by using size cutoffs.

RESULTS

The mean follow-up (+/- SD) was 9.4 +/- 6.6 years among the patients alive at latest follow-up. At 10 years, the CSS and MFS for clear cell RCC (n = 682) were 89.1% and 88.6%, respectively; for papillary RCC (n = 122), they were 95.5% and 93.8%; and for chromophobe RCC (n = 33), they were both 100%. The differences in CSS (P = 0.013) and MFS (P = 0.023) between clear cell RCC and the other subtypes were statistically significant. For clear cell RCC, tumor size and Fuhrman grade were independently associated with CSS and MFS (P <0.001). A transition in risk occurred for tumor sizes between 4.5 and 5.0 cm, and the tumor size cutoff of 5.0 cm had the highest concordance index for predicting CSS and MFS.

CONCLUSIONS

RCC subtype is a strong independent prognostic variable for patients with pT1 RCC treated with radical nephrectomy. For clear cell RCC, Fuhrman grade and tumor size are independently associated with CSS and MFS.

Mathematical model to predict individual survival for patients with renal cell carcinoma

PURPOSE

To develop a multivariate model and mathematical formula capable of calculating personalized survival for renal cell carcinoma (RCC) patients with clinically available variables.

PATIENTS AND METHODS

A total of 477 patients out of 661 undergoing nephrectomy at the University of California Los Angeles between 1989 and 1999 were eligible for evaluation and formed the analyzed cohort for this retrospective study. Time to death was the primary end point assessed. Univariate analysis for 14 to 20 variables was conducted, followed by a multivariate Cox analysis. The variables that provided independent information as to the time of death for metastatic and nonmetastatic patients were coded and incorporated into a function based on the Nadas equation principle.

RESULTS

For nonmetastatic patients, the significant variables in the multivariate analysis were Fuhrman's grade and Eastern Cooperative Oncology Group performance status. For the metastatic patients, Fuhrman's grade, 1997 classification T stage, number of symptoms, nodal involvement, and immunotherapy were independent predictors for survival. These variables, based on the Cox multivariate regression model, were implanted into an exponential Nadas equation. The expected survival predicted by use of the Nadas equations faithfully describes the actual survival based on Kaplan-Meier curves.

CONCLUSION

We have developed mathematical equations for estimating survival after radical nephrectomy for RCC. The resulting formulas are capable of better tailoring survival estimates for a specific patient and are based on widely accepted clinical prognostic variables. On validation with external data, this type of representation can be used as a tool for the determination of personalized prognosis and may be useful for patient education and counseling.

The changing natural history of renal cell carcinoma

PURPOSE

Our understanding of the natural history of renal cell carcinoma, the role of nephrectomy, the benefits of immunotherapy and the possibilities of new technologies are evolving and being integrated with advances in classification and staging. We reviewed the relevant literature to clarify these pertinent questions and provide a current review of the changes in the epidemiology, treatment and prognosis of patients with renal cell carcinoma.

MATERIALS AND METHODS

We comprehensively reviewed the peer reviewed literature on the current management of and results of treatment for renal cell carcinoma.

RESULTS

The incidence of and mortality from renal cell carcinoma have continuously increased during the last 50 years. Despite this increase in the number of new patients and consequently the number of deaths yearly the percent of those surviving for 5 years has notably improved. Factors related to improved survival include advances in renal imaging, earlier diagnosis, improved staging, better understanding of prognostic indicators, refinement in surgical technique and the introduction of immunotherapy approaches for advanced disease.

CONCLUSIONS

Currently patients with localized and metastatic renal cell carcinoma have had improvements in outlook and the therapeutic options available have expanded.

The changing natural history of renal cell carcinoma

PURPOSE

Our understanding of the natural history of renal cell carcinoma, the role of nephrectomy, the benefits of immunotherapy and the possibilities of new technologies are evolving and being integrated with advances in classification and staging. We reviewed the relevant literature to clarify these pertinent questions and provide a current review of the changes in the epidemiology, treatment and prognosis of patients with renal cell carcinoma.

MATERIALS AND METHODS

We comprehensively reviewed the peer reviewed literature on the current management of and results of treatment for renal cell carcinoma.

RESULTS

The incidence of and mortality from renal cell carcinoma have continuously increased during the last 50 years. Despite this increase in the number of new patients and consequently the number of deaths yearly the percent of those surviving for 5 years has notably improved. Factors related to improved survival include advances in renal imaging, earlier diagnosis, improved staging, better understanding of prognostic indicators, refinement in surgical technique and the introduction of immunotherapy approaches for advanced disease.

CONCLUSIONS

Currently patients with localized and metastatic renal cell carcinoma have had improvements in outlook and the therapeutic options available have expanded.

Stage pT1 conventional (clear cell) renal cell carcinmoa: pathological features associated with cancer specific survival

PURPOSE

The features predictive of aggressive behavior in stage pT1 conventional (clear cell) renal cell carcinoma are not completely known. We evaluated pathological features in a large series of stage pT1 conventional renal cell carcinoma cases and examined the association of these features with cancer specific survival.

MATERIALS AND METHODS

Patients with solitary stage pT1 conventional renal cell carcinoma who underwent radical nephrectomy between 1970 and 1997 were eligible for study. For each of the 46 patients who died of renal cell carcinoma we selected a stratified random sample of at least 3 year matched controls who were still alive or dead of other causes. The study included 277 patients. We evaluated patient age at nephrectomy, sex, tumor size, Fuhrman grade, necrosis and sarcomatoid component. Univariate and multivariate Cox proportional hazards models were fit to assess the features associated with cancer specific survival.

RESULTS

Multivariate modeling revealed that tumor size, Fuhrman grade and necrosis were jointly significantly associated with cancer specific survival. Of the 4.5, 5 and 6 cm. tumor size cutoffs examined on univariate analysis a cutoff of 5 cm. or greater was most predictive of cancer specific survival.

CONCLUSIONS

In stage pT1 conventional renal cell carcinoma Fuhrman grade, tumor necrosis and tumor size together were jointly significantly associated with cancer specific survival. Specifically of the tumor size cutoffs analyzed the 5 cm. cutoff was most predictive of cancer specific survival.

The prognostic value of DNA ploidy in small renal cell carcinoma

The objective was to study the prognostic value of Deoxyribonucleic Acid (DNA) ploidy status in small renal cell carcinomas (RCC). The nuclear DNA content of renal cell carcinoma tissues from patients who underwent radical or partial nephrectomy has been analyzed by flow cytometry. The results of the DNA ploidy have been correlated to the size of tumors and disease progression. Of the 50 patients with RCC studied, 8 (16%) progressed. Tumors with non-diploid DNA patterns were found in 24 (48%) of the 50 patients and in 4 of the 8 patients who progressed. Overall the median tumor size in our series was 50 mm. A tumor diameter of 50 mm or less was measured in 26 patients (group I) and above 50 mm in 24 (group II). Non-diploid DNA patterns were found in 11 (42.3%) and 13 (54.2%) patients in groups I and II, respectively. This difference between the groups was not significant. Only one patient in group I (3.8%) developed metastatic disease and died 72 months after the operation. In group II, 7 patients (29.2%) presented tumor progression and 5 died of metastatic disease. The survival probability in group I was 95% at 5 and 8 years (95% CI 70% to 99%) and for group II 94% at 5 years (95% CI 67%-99%) and 67% at 8 years (95% CI 39%-83%). DNA ploidy is an inaccurate predictor of tumor behavior in patients with RCC, even in small tumors. Tumor size is a more significant predictor of outcome.

Pathology of kidney tumors

The classification of epithelial tumors of the kidney has undergone considerable change in the last two decades. Systems based on cytoplasmic characteristics and cytogenetic analysis have expanded our understanding of this group of tumors. These new, nontraditional systems have led to the development of a more clinically significant pathological classification (1,2). Although many questions remain unanswered and debate continues concerning the validity of these proposals, research studies on epithelial neoplasms of the kidney must take these advances into consideration. Scientific studies of any type should incorporate information regarding the type of tumor(s) included in the study group. This chapter briefly reviews the accepted subtypes of renal epithelial neoplasms, with a focus on the morphological features that distinguish them.

Biomarkers of renal cell carcinoma. Past and future considerations

Renal cancer includes several distinct entities with a range of biologic and clinical behaviors from relatively indolent to extremely aggressive tumors. Although conventional prognostic factors such as stage and grade are quite useful, other clinical, laboratory, and pathologic findings are now believed to have additional predictive values. This article reviews the literature on the potential utility of biomarkers in renal cell carcinoma. To date, only a few biomarkers, such as Ki-67, appeared to be potentially useful for monitoring renal cancer patients. New biomarkers including MN/CA9 and circulating cell detection require further and extensive studies to assess their potential clinical utility.

Independent value of tumor size and DNA ploidy for the prediction of disease progression in patients with organ-confined renal cell carcinoma

BACKGROUND

Greater than 20% of patients with apparently localized renal cell carcinoma (RCC) present with disease progression after surgery. The objective of the current study was to improve the ability of clinicians to predict prognosis in patients with localized RCC.

METHODS

The authors studied 154 patients with organ-confined RCC classified as pT1 to pT2-pN0-M0 who underwent radical nephrectomy. Follow-up ranged from 24-128 months (median, 72 months). Several morphologic parameters of the tumor were considered. DNA content was analyzed by flow cytometry and tumor size was determined from the surgical specimen. A Cox proportional hazards regression model was used to identify significant independent prognostic factors for disease progression.

RESULTS

At 5 and 10 years of follow-up, disease free survival was found to be 87% and 86%, respectively. Univariate analysis revealed that DNA content, Furhman grade, and tumor size had a statistically significant predictive value for disease progression, whereas, with regard to grade, the difference was significant only between patients with Grade 3 tumors and all other patients with Grade 1-2 tumors (P < 0. 0001). Although DNA content was found to correlate with tumor size (P < 0.0001), multivariate analysis showed that these were the only significant independent predictors of disease progression. The sum of DNA content and tumor size therefore was considered to distinguish separate risk groups. For a patient with diploid RCC, the risk of progression increased from 4% if the tumor size was 3 cm to 43% if the tumor size was 10 cm. For a patient with nondiploid RCC, this risk was 32% if the tumor size was 3 cm, increasing to 99% for tumors measuring 10 cm.

CONCLUSIONS

Stratification of organ-confined RCC according to tumor size and DNA content could possibly provide more information that could be useful in the selection of individuals with significantly different risks of disease progression.

Intratumoral heterogeneity of DNA content in renal cell carcinoma and its prognostic significance

BACKGROUND

A multiple sampling study was performed on 124 specimens of renal cell carcinomas to analyze the consistency and reliability of DNA measurements. The authors investigated intratumoral DNA heterogeneity and its role as a adverse prognostic factor for disease progression.

METHODS

DNA content was analyzed by flow cytometry on three different samples of the same tumor. The Cronbach alpha coefficient was used to assess the reliability and a Cox proportional hazards model was used to test the effect of DNA ploidy heterogeneity on time of disease progression.

RESULTS

The agreement among the DNA ploidy samples was high. The number of aneuploid findings increased significantly with the number of samples analyzed. The presence of non-diploid cell populations was a significant adverse predictive value for disease progression. However, the authors were unable to demonstrate that intratumoral heterogeneity DNA content had any influence on the biological behavior of the tumor.

CONCLUSIONS

Determination of DNA ploidy based on single samples may be inaccurate. Spatial variation in DNA ploidy is a feature of renal cell carcinoma; however, its biologic significance remains to be demonstrated.

Grading of renal cell carcinoma

Recognition of the prognostic utility of renal cell carcinoma grading is not a recent development. Most pathologists in the United States use the Fuhrman grading system; however, this system is fraught with limitations and controversies. The Fuhrman grading system makes initial sense and seems simple to apply; however, it is hampered by several limitations, the foremost being that there is no consensus on the prognostic significance of the different grades of renal cell carcinoma.

Risk and prognosis in renal neoplasms. A pathologist's prospective

The incidence of renal carcinoma has increased in the United States over the last two decades. An increased rate of detection of incidental tumors and a variety of exogenous risk factors may be responsible for this increase. Pathologic stage and nuclear grade remain the most important and practical prognostic features, however, the specific tumor type has emerged as important as the cytogenetic validation of recent renal carcinoma classification. Proliferation markers, DNA ploidy, and morphometry have powerful predictive value but are handicapped by cost and complexity. The search continues for molecules of diagnostic and prognostic utility that may also impact invasive and metastatic capability for this group of neoplasms whose course is principally determined by the completeness of the original resection.

Diagnosis and classification of renal cell carcinoma

Although substantial agreement exists in most aspects of diagnosis and staging of renal cell carcinoma, further work is needed to resolve unsettled issues regarding precursor lesions, grading, and the prediction of outcome for individual patients.

Assessment of proliferating cell nuclear antigen expression and prognosis in patients with renal cell carcinoma with pulmonary metastases

BACKGROUND

The presence of proliferating cell nuclear antigen (PCNA) has been suggested as a more important prognostic marker than either grade or mitotic index in the prognosis of patients with renal cell carcinoma. We assessed the immunoreactivity of PCNA in primary lesions and pulmonary metastases from patients with renal cell carcinoma and correlated the results with various histopathologic features and prognostic factors.

METHODS

We studied the relationship between PCNA expression and clinical prognostic factors from resected primary lesions and pulmonary metastases from 10 patients and primary lesions from 32 patients with renal cell carcinoma without metastases. The cells were immunohistochemically stained with PCNA monoclonal antibody (PC-10) and 1000 nuclei were counted. The results were expressed as a ratio of stained to total cells (PCNA labeling index, LI %).

RESULTS

The PCNA LI of pulmonary metastatic nuclei was significantly higher than the PCNA LI of renal lesions either from patients with (P < 0.05) or without (P < 0.01) metastases. Also, the mean PCNA LI of the pulmonary lesions in patients dying within 3 years of diagnosis was higher than the mean PCNA LI of patients surviving greater than 3 years.

CONCLUSION

Our findings suggest that the PCNA LI, which was determined by immunohistochemical analysis, is an important marker reflecting the biologic behavior of renal cell carcinomas. The degree of PCNA expression in this study was of prognostic significance.

Comparison of flow cytometric DNA content analysis in fresh and paraffin-embedded ovarian neoplasms: a prospective study

DNA ploidy analysis was performed on both fresh and paraffin-embedded preparations from each of 54 malignant ovarian neoplasms. Aneuploidy was detected in both the fresh and the paraffin-embedded tissue in 19 out of 54 (35%) malignant cases. In addition, aneuploidy was detected exclusively in fresh tissue in seven of the malignant cases, and exclusively in paraffin-embedded tissue in one of the malignant cases, yielding a total of 27 out of 54 (50%) aneuploid cases. The correlation coefficient (r-value) for fresh and paraffin-embedded tissue ploidy analysis in the malignant specimens was 0.91. Although the frequency of recurrence was higher and overall survival lower in the malignant aneuploid specimens of both types, the combined analysis of DNA and survival rates indicated superior prognostic significance of fresh tissue. Of the seven patients in whose specimens aneuploidy was detected exclusively in fresh tissue, all died of recurrent disease during the follow-up period. Our finding indicates that data generated by flow cytometry analysis of formalin-fixed tissue should be interpreted with caution before the data can be used to draw clinical inferences.

Sarcomatoid renal cell carcinoma: the chromophobe connection

Eleven cases of sarcomatoid renal cell carcinoma were studied to determine the relative frequency of various subtypes of renal cell carcinoma that may be associated with sarcomatoid transformation. The epithelial components in these tumors were subcategorized according to established histologic criteria into chromophobe carcinoma (n = 6 cases), clear cell carcinoma (n = 3), papillary carcinoma (n = 1), and indeterminate (n = 1). In nine cases, material was available for immunohistochemical and DNA ploidy studies. The sarcomatoid component in all cases showed positivity for epithelial membrane antigen cytokeratin, indicating an epithelial derivation of these cells. Staining for mesenchymal markers was mostly negative, except for vimentin, which reacted strongly in all cases. DNA ploidy studies using flow cytometry and cell image analysis provided very similar results. Five of five chromophobe sarcomatoid carcinomas showed hypodiploid cell lines in the epithelial areas, whereas the sarcomatoid components mostly showed aneuploid peaks. In the remaining cases, DNA ploidy pattern was more variable. These findings indicate that chromophobe carcinoma may be the most frequent epithelial component associated with sarcomatoid renal cell carcinoma.

Prospective evaluation of fine needle aspiration of small, solid renal masses: accuracy and morbidity

OBJECTIVES

To determine the accuracy and clinical utility of fine needle aspiration (FNA) of small, solid renal masses.

METHODS

A total of 25 patients with small (less than 5.0 cm), solid, clinically localized renal masses were prospectively identified and evaluated with computed tomography guided FNA with analysis for presence of malignant cells and determination of nuclear grade. The final pathologic findings were used for comparison in each case. All patients had renal cell carcinoma and were managed with radical or partial nephrectomy; 3 had low-grade lesions (Fuhrman's grade 1/4), 2 had high-grade lesions (Fuhrman's grade 4/4), and all other patients had intermediate-grade lesions (Fuhrman's grade 2/4 or 3/4) on final histopathologic assessment.

RESULTS

Overall, 10 aspirations yielded diagnostic malignant cells, and 9 were read as rare as rare atypical cells suspicious for malignancy. The remainder were negative (n = 6). Correlation with final nuclear grade was observed in eight instances and discordance in two instances. Subcapsular hematomas were observed at the time of surgery in 10 patients, but in no instance was the operation adversely affected.

CONCLUSIONS

The diagnostic yield of FNA of small, solid renal masses appears to be too low to justify the potential morbidity of the procedure.

Clinicopathologic study of 97 cases of small renal cell carcinomas using DNA flow cytometric analyses

The incidence of small renal cell carcinomas (RCC) has increased recently as diagnostic imaging techniques have improved. The indications for partial nephrectomy for small RCC confined to the kidney are still controversial. Ninety-seven small RCC 2.5 cm or smaller, including incidental, occult, and dialysis associated carcinomas obtained at surgery or autopsy were examined. Various clinicopathologic parameters were assessed and survival was analyzed using the Kaplan-Meir method. Seventy-eight cases were incidental carcinomas. Carcinomas caused death in five cases, four of which had initial signs of metastatic disease. Differences in survival between patients with expansive and invasive (intermediate and infiltrating) growth patterns, solid and other structural patterns, clear and other cell types, grade 1 and higher grades of nuclear atypia, and with and without lymph node metastasis were statistically significant. All surgical cases were alive except one who died of another disease. Poor prognostic factors seen in five fatal autopsy cases included invasive growth pattern, solid structural pattern, spindle cells, grade 3 nuclear atypia, and Bellini duct carcinoma. Small RCC may be treated with partial nephrectomy provided they do not show these features, although there is low risk of recurrence or development of de novo cancer.

Proliferating cell nuclear antigen expression in renal cell carcinoma. Prognostic implications

The proliferating cell nuclear antigen (PCNA) is a nuclear protein associated with cells in active cell cycle. The expression of PCNA was evaluated immunohistochemically in 3-6 samples from 68 renal cell carcinomas. A total of 279 tumour samples were analysed using the monoclonal antibody PC-10, and the percentage of positively stained cell nuclei (PCNA-index) was determined. The tumour PCNA-index varied between 0.9-17.5%, with a mean value of 4.9%, significantly different from normal kidney cortex samples (p < 0.001). A significant difference in PCNA-index was found between the different tumour grades, whereas no significant difference was found between clinical stages. Concerning DNA ploidy, aneuploid tumours had a significantly higher PCNA-index compared with diploid tumours (p = 0.002). There was a significant survival advantage for patients with low tumour PCNA-indices (< 3.5%) compared with those with high indices (> 3.5%, p = 0.019), a difference also found for patients with non-metastatic disease (p = 0.012). Our data shows that PCNA expression can be analysed and that it may constitute an additional prognostic parameter for patients with renal cell carcinoma.

Flow cytometric quantitation of the proliferation-associated nuclear antigen p105 and DNA content in patients with renal cell carcinoma

BACKGROUND

Although tumor stage and grade are important prognostic parameters for patients with renal cell carcinoma, postnephrectomy survival is often difficult to predict. Therefore identifying patients at high risk for disease progression is critical. Using two-color flow cytometry, DNA and proliferation-associated nuclear antigen p105 contents were measured simultaneously in 75 patients with renal cell carcinomas and the ability of these results to predict the survival was assessed.

METHODS

Flow cytometric study of the proliferation-associated nuclear antigen p105 was done on cancer cell suspensions from 75 patients with renal cell carcinomas. By setting the cutoff line at the level between the brighter and the dimmer subpopulations in the diploid G0G1 region, the p105-labeling rate was calculated by the p-105DNA dual fluorescence analysis.

RESULTS

The mean p105-labeling rate was 66.8% (median: 67.6%; range: 33.9-93%). The 5-year survival rate of patients with high p105-labeling tumors was significantly lower than that of patients with low labeling tumors (P < 0.05). The following factors were examined univariantly as prognostic factors: Robson's stage, DNA ploidy pattern, grade, and p105-labeling rate. All of these factors except for DNA ploidy pattern were prognostic. The Cox multivariate regression analysis was performed with the three statistically significant variables. Accordingly, these three factors were significantly associated with survival rate and were found to be independent prognostic factors.

CONCLUSIONS

The measurement of p105 may provide useful information for predicting prognosis of patients with renal cell carcinoma.

Prognostic significance of nuclear DNA content and proliferative activity in renal cell carcinomas. A clinicopathologic study of 58 patients using mitotic count, MIB-1 staining, and DNA cytophotometry

BACKGROUND

For a variety of human malignancies, static DNA cytophotometry and immunostaining for the Ki-67 antigen using the antibody MIB-1 have provided significant prognostic information.

METHODS

Surgical specimens of 58 renal cell carcinomas (RCCs) were investigated by conventional histology, DNA cytophotometry, and MIB-1 immunostaining.

RESULTS

The MIB-1 indices and DNA data were found not only to be significantly correlated with various other morphologic parameters, but also to the clinical behavior of RCC. In the course of this study (median observation period: 31 months), 27% of patients died from RCC. None of these patients belonged to the group of 37 patients with RCCs exhibiting diploid or euploid DNA histograms. Lethal outcome occurred in only 16 of the 21 patients (76%) with noneuploid or aneuploid histogram tumors (P < 0.0001). According to their MIB-1 indices and upon choosing different cutoff levels, the 58 RCCs were categorized into 2 groups with either low or high proliferative activity. Using the median and the mean MIB-1 index as cutoffs, none of the patients with tumors showing low proliferative activity had died, whereas 16 of 29 patients (55%) or, respectively, 16 of 25 patients (64%) with tumors exhibiting high proliferative activity, had died from RCC (P < 0.0001).

CONCLUSIONS

In addition to tumor grade and stage, both a high MIB-1 index and a noneuploid or aneuploid DNA histogram of a given RCC have the potential to identify tumor patients with an impaired prognosis.

Heterogeneity and progression of renal cell carcinomas as revealed by DNA cytofluorometry and the significance of the presence of polyploid cells

With special attention to the presence of polyploid cells, we examined heterogeneity and progression of renal cell carcinomas. We separated 116 blocks from 51 tumors into several specimens according to the histologic findings, and analyzed their DNA ploidy patterns. Thirty-one tumors (61%) were aneuploid, 29 of which showed intratumoral DNA ploidy heterogeneity. Diploid cell lines were observed in 47 tumors (92%). Polyploid cells in the diploid component were more frequently found in tumors with mixed diploid and aneuploid patterns than in the purely diploid tumors. Of the diploid cases, higher stage cases tended to have a higher incidence of polyploid cells than the lower stage cases. The incidence of aneuploid cases and DNA heterogeneity became greater as the tumors progressed. Aneuploid cases had a poorer outcome than did the diploid cases. If diploid cases with polyploid cells were classified as aneuploid cases, the difference in the survival rate between the diploid and aneuploid cases became more significant. Diploid renal cell carcinomas with polyploid cells may be an intermediate stage between diploidy and aneuploidy. Analyzing renal cell carcinomas for the presence of polyploid cells is useful for differentiating diploidy, which is actually aneuploid, from pure diploidy.

Flow-cytometric DNA analysis of paraffin-embedded renal cell carcinoma tissue from patients treated by parenchymal-sparing surgery

OBJECTIVE

To determine the utility of deoxyribonucleic acid (DNA) ploidy pattern, detected by flow cytometry, in predicting the outcome of renal cell carcinoma (RCC).

PATIENTS AND METHODS

DNA content was retrospectively assessed by flow cytometry in 28 primary paraffin-embedded RCCs from 24 patients (16 men and eight women, mean age 61.9 years, range 40-89) who had undergone renal parenchymal-sparing surgery.

RESULTS

Tumour recurred locally in three patients, two with diploid tumours and one with aneuploid tumour. Two patients with diploid tumours had metastatic disease 11-58 months after surgery. Only one patient with aneuploid tumour developed metastatic disease. There was no difference in local recurrence or metastases with the type of renal parenchymal-sparing surgery used (enucleation or partial nephrectomy) nor any significant difference in overall survival (P = 0.11).

CONCLUSION

While DNA content might be of considerable predictive value for patients with RCC, these results showed that there was no difference in mortality rate, recurrence rate, or type of renal parenchymal-sparing surgery used between aneuploid and diploid tumours.