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

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.

Identifying DNA mismatches at single-nucleotide resolution by probing individual surface potentials of DNA-capped nanoparticles

Here, we demonstrate a powerful method to discriminate DNA mismatches at single-nucleotide resolution from 0 to 5 mismatches (χ₀ to χ₅) using Kelvin probe force microscopy (KPFM). Using our previously developed method, we quantified the surface potentials (SPs) of individual DNA-capped nanoparticles (DCNPs, ∼100 nm). On each DCNP, DNA hybridization occurs between ∼2200 immobilized probe DNA (pDNA) and target DNA with mismatches (tDNA, ∼80 nM). Thus, each DCNP used in the bioassay (each pDNA-tDNA interaction) corresponds to a single ensemble in which a large number of pDNA-tDNA interactions take place. Moreover, one KPFM image can scan at least dozens of ensembles, which allows statistical analysis (i.e., an ensemble average) of many bioassay cases (ensembles) under the same conditions. We found that as the χ_n increased from χ₀ to χ₅ in the tDNA, the average SP of dozens of ensembles (DCNPs) was attenuated owing to fewer hybridization events between the pDNA and the tDNA. Remarkably, the SP attenuation vs. the χ_n showed an inverse-linear correlation, albeit the equilibrium constant for DNA hybridization exponentially decreased asymptotically as the χ_n increased. In addition, we observed a cascade reaction at a 100-fold lower concentration of tDNA (∼0.8 nM); the average SP of DCNPs exhibited no significant decrease but rather split into two separate states (no-hybridization vs. full-hybridization). Compared to complementary tDNA (i.e., χ₀), the ratio of no-hybridization/full-hybridization within a given set of DCNPs became ∼1.6 times higher in the presence of tDNA with single mismatches (i.e., χ₁). The results imply that our method opens new avenues not only in the research on the DNA hybridization mechanism in the presence of DNA mismatches but also in the development of a robust technology for DNA mismatch detection.

Patterns of recurrence and surveillance strategies for renal cell carcinoma following surgical resection

Renal cell carcinoma (RCC) remains one of the most lethal urologic malignancies, with up to 40% of patients eventually dying of cancer progression. Despite advances in the diagnosis, staging and treatment of patients with RCC, approximately a third of patients who undergo surgery for clinically localized RCC will suffer a recurrence. Timely identification of recurrences following surgical extirpation is imperative in the treatment of these patients. RCC is known to metastasize through hematogenous routes of spread to distant organ sites and via lymphatic channels to regional lymph nodes. The path of tumor escape is associated with diverse clinical outcomes and a unique tumor biology. A consensus on surveillance regimens for patients following surgical resection of localized disease is lacking. The most extensively used system for providing prognostic information regarding survival and recurrence of disease has historically been the tumor-node-metastasis (TNM) classification system. As a result, most contemporary surveillance protocols have tailored follow-up regimens according to stage-based stratifications. Numerous studies have recently demonstrated that certain clinical and histopathological factors can improve the prediction of tumor recurrence. The incorporation of these prognostic factors into stage-based stratification models should be better than stage alone in attempting to provide a rational approach to identifying treatable recurrences while minimizing unnecessary exams and tests, as well as patient anxiety. Advances in the understanding of the pathogenesis, behavior and molecular biology of RCC have paved the way for developments that may enhance early diagnosis and prognostication, and improve survival for patients. Lastly, molecular markers should, in the future, revolutionize surveillance protocols for RCC by tailoring follow-up to specific molecular classifications.

Prognostic biomarkers in renal cell carcinoma

A hallmark of renal cell carcinoma is its variable prognosis. Surgical resection of primary renal cell carcinoma can be curative when the disease is localized. However, approximately 20% of patients with early stages of localized renal cell carcinomas subsequently develop metastasis after the primary tumor is removed. The median survival for patients with metastatic disease is approximately 13 months. Therefore, there is a great need for biomarkers to predict metastasis and prognosis. Many prognostic biomarkers were studied in the past decade. In recent years, several promising biomarkers, including CAIX, B7-H1 and IMP3, have also been identified by large retrospective studies. Further validation of these biomarkers is essential to transfer the research data into clinical practice. Eventually, an outcome prediction model with biomarkers, staging system and other risk factors will identify high-risk patients with likelihood of progression and formulate different follow-up protocols or systematic treatments for these patients.

In vivo aneuploidization during the expansion of renal adenocarcinoma

BACKGROUND/AIMS

A correlation has been observed between DNA ploidy and other prognostic parameters such as tumor stage and grade. The present study evaluates tumor aneuploidization during renal adenocarcinoma expansion and growth.

METHODS

A total of 252 renal tumors were analyzed between 1969 and 2001. Evaluated variables were age, TNM, Fuhrman classification, histology, size and DNA. A tumor was homogeneous when all the samples were diploid or aneuploid, and a heterogeneous tumor was the coexistence of aneuploid and diploid samples, or all-aneuploid with different aneuploid clones.

RESULTS

A total of 224 tumors were included (coefficient of variation <8). The DNA study classified 129 (57.6%) as diploid and 95 (42.4%) as aneuploid. The percentage of aneuploid tumors increased significantly with the pathological stage. Both aneuploid patterns were also significantly more frequent in advanced pathological stages. Tumors with multiple aneuploid clones (n = 17) were significantly more frequent in tumors measuring `4 cm. Both aneuploid patterns showed no differences in survival (p = 0.83), indicating that the heterogeneous pattern probably represents an intermediate step between diploid and homogeneous aneuploid tumor status.

CONCLUSIONS

The aneuploid pattern is more common in more advanced stages of the disease, with no clear correlation to primary tumor size. This suggests gradual aneuploidization with tumor expansion and growth.

[Incidental renal cancer in young adults: clinical and histopathological findings]

OBJECTIVE

to evaluate the clinical and pathological renal cancer (CR) characteristics in our series of tumours, analyzing its impact in the group of age less than 40 years.

MATERIAL AND METHODS

We studied 294 patients with CR. The pathologic characteristics were analyzed and DNA ploidy pattern of the surgical pieces were done in 252 patients. The patients were divided in two groups based on age, greater or less to 40 years, well then clinical and pathologic characteristics were compared between.

RESULTS

Of all patients, 26 of 294 patients (8,94%) were included in the young age group (less to 40 years). We did not found differences between both groups comparing stage, tumoral volume, treatment realized or DNA ploidy pattern, but in nuclear grade with more aggressive tumours in young people (p=0,0018), without differences in recurrence-free survival or actuarial disease specific survival rate.

CONCLUSIONS

The findings in our study indicate that the natural history and outcome of the RC is similar in both older and younger patients. Therefore, in our opinion, the management of CR in young people should be established with independence of the age.

Prognostic significance of CD44, platelet-derived growth factor receptor alpha, and cyclooxygenase 2 expression in renal cell carcinoma

CONTEXT

Pathologic stage is the main prognostic factor for predicting outcome in renal cell carcinoma (RCC). Because of its unreliability in predicting tumor progression, other factors are needed to provide additional prognostic information.

OBJECTIVE

The expression of CD44, cyclooxygenase 2, and platelet-derived growth factor receptor alpha (PDGFR-alpha) was evaluated as a potential prognostic factor for survival in patients with RCC.

DESIGN

Sixty-two patients (42 men and 20 women; median age, 61 years), undergoing partial (10 cases) or radical (55 cases) nephrectomy for RCC were retrospectively analyzed by immunohistochemical analysis for CD44, cyclooxygenase 2, and PDGFR-alpha expression. Impact of various factors on disease-specific and overall survival was calculated using Cox proportional hazards models.

RESULTS

There was a gradual increase in CD44 and cyclooxygenase 2 expression with increasing RCC nuclear grade. In contrast, PDGFR-alpha expression showed no consistent relationship with nuclear grade. On univariate analysis, metastasis at time of surgery (P < .001), tumor size (P = .004), pathologic stage group (P = .001), and nuclear grade (P = .004) were correlated with disease-specific survival. On multivariate analysis, only the presence of metastasis at diagnosis (P < .001) was significant. For overall survival, metastasis (P < .001), tumor size (P = .02), pathologic stage group (P = .01), nuclear grade (P = .003), and PDGFR-alpha (P = .03) were significant on univariate analysis. Only metastasis (P = .001) and PDGFR-alpha (P = .03) were significant on multivariate analysis.

CONCLUSIONS

When combined with other variables, PDGFR-alpha expression in RCC may provide additional predictive value related to the patient's overall survival. However, CD44 and cyclooxygenase 2 do not seem to be independent prognostic indicators in predicting outcomes for patients with RCC.

Dynamic outcome prediction in patients with clear cell renal cell carcinoma treated with radical nephrectomy: the D-SSIGN score

PURPOSE

To date all prediction models for patients with renal cell carcinoma have estimated outcome in static fashion starting from the date of surgery only. We created a dynamic outcome prediction model for continual surveillance that accounts for the disease-free interval following surgery.

MATERIALS AND METHODS

We identified 1,560 patients treated with radical nephrectomy for pM0 clear cell renal cell carcinoma between 1970 and 1999. The previously published stage, size, grade and necrosis score was used to stratify patients according to the risk of death from renal cell carcinoma. Cancer specific survival rates were calculated using the Kaplan-Meier method at surgery and at various disease-free intervals following surgery.

RESULTS

At last followup 461 of the 1,560 patients had died of renal cell carcinoma at a median of 3.1 years following surgery. Median followup in patients still alive was 11.2 years. Patient outcome improved as the disease-free interval following surgery increased. For example, patients with a stage, size, grade and necrosis score of 5 had an estimated 5-year cancer specific survival rate of 69.6% at surgery. However, those who survived without disease for 1, 2 and 3 years following surgery had adjusted estimated 5-year cancer specific survival rates of 81.9%, 91.9% and 93.2%, respectively. Patients with a stage, size, grade and necrosis score of 7 had a 5-year cancer specific survival rate of 44.9% at surgery, which increased to 63.3%, 71.0% and 72.8% after 1 to 3 years of disease-free followup, respectively.

CONCLUSIONS

Within each stage, size, grade and necrosis score cancer specific survival rates increase as the disease-free interval following surgery increases. We present a dynamic outcome prediction model that allows clinicians to continually adjust surveillance as the disease-free interval increases.

Nonmetastatic renal-cell carcinoma: is it really possible to define rational guidelines for post-treatment follow-up?

Defining rational follow-up guidelines in patients treated for cancer is important, from both a medical and an economical perspective. Renal-cell carcinoma is reputed to be unpredictable in its course and only a few, and often contradictory, follow-up guidelines exist for patients treated for nonmetastatic renal-cell carcinoma. Recent advances in tumor biology have contributed to a better understanding of this cancer and have indicated that personalized follow-up regimens, based on tumor and host molecular characteristics, might be possible in the near future.

Prognostic significance of ploidy, MIB-1 proliferation marker, and p53 in renal cell carcinoma

BACKGROUND

Pathologic stage is currently the best prognostic factor for predicting outcomes in renal cell carcinoma. The objective of this study was to evaluate the role of DNA ploidy, p53, and Ki-67 (MIB-1) as individual and combined prognostic factors for survival in patients with renal cell carcinoma (RCC).

STUDY DESIGN

From 1995 to 2004, 117 patients (78 men and 39 women; mean age 57.34 years), undergoing partial (n = 22) or radical (n = 95) nephrectomy for renal cell carcinoma were retrospectively analyzed. Analysis of MIB-1, p53, and DNA ploidy was performed. Disease-free and overall survival was calculated using Cox proportional hazard models. A combined score was given to incorporate p53, MIB-1, and ploidy as a single variable.

RESULTS

On univariate analysis, tumor size, nuclear grade, MIB-1 <10% (p = 0.0059), ploidy (p = 0.0124), pathologic stage group, metastasis at time of operation, and combined score (p = 0.0024) were markedly associated with disease-free survival. On multivariate analysis, only metastasis and pathologic stage were pronounced. For overall survival, size, nuclear grade, MIB-1 <10% (p = 0.0167), pathologic stage group, metastasis, and combined score (p = 0.0456) were pronounced on univariate analysis. Only metastasis was pronounced on multivariate analysis.

CONCLUSIONS

We incorporated a combined score to evaluate MIB-1, ploidy, and p53 as a single variable. A combined score is able to give a stronger predictive value of the cellular characteristics of each tumor. Individually and combined with p53, MIB-1, and ploidy were of prognostic significance on univariate analysis. Pathologic stage and presence of metastasis remain the best predictors of disease-free survival.

Bcl-2 protein and DNA ploidy in renal cell carcinoma: do they affect patient prognosis?

AIM

The aim of the present study was to correlate bcl-2 protein expression and DNA-ploidy status with established prognostic parameters in renal cell carcinoma (RCC) and to examine their impact on disease progression and patient survival.

METHODS

Both parameters were prospectively measured in 50 consecutive radical nephrectomy specimens using flow cytometry. They were correlated with the tumor grade, stage and histological type. Kaplan-Meier survival analysis for all parameters was performed.

RESULTS

Bcl-2 protein expression was higher in RCC compared to normal renal tissue (P < 0.0001). Aneuploid tumors had higher bcl-2 expression compared to diploid tumors (P = 0.015). Bcl-2 expression and DNA content were not correlated with tumor histological types (P = 0.277/P = 0.419), grades (P = 0.690/P = 0.449), T categories (P = 0.637/P = 0.585) or stages (P = 0.726/P = 0.800). Median follow-up time was 46 months (range, 5-84) with a mean overall survival of 61.8 months (95% confidence interval, 53.7-69.9). Tumor stage was the only statistically important prognostic factor (P = 0.0045).

CONCLUSION

Although Bcl-2 expression was correlated with tumor DNA content, the prognostic value of these two parameters following radical nephrectomy was not established.

INTRACAPSULAR CLEAR CELL RENAL CARCINOMA: PLOIDY STATUS IMPROVES THE PROGNOSTIC VALUE OF THE 2002 TNM CLASSIFICATION

PURPOSES

The TNM classification has been revised for the 2002 edition of the UICC publication to better stratify patients with intracapsular renal cell carcinoma (RCC) but few studies have been published to date to validate this new classification. Moreover, additional prognostic factors seem to be necessary to improve the prediction of intracapsular tumor aggressiveness and the definition of patient subgroups at high risk for metastases. We report the long-term results of the new TNM scheme. We evaluated the impact of DNA content, S-phase and MIB-1 (Dako, Glostrup, Denmark) score.

MATERIALS AND METHODS

A total of 136 patients with intracapsular clear cell RCC and a mean followup of 74 months were reclassified. Tumor specific survival (TSS) was compared with nuclear grade (NG), DNA content and proliferative status (S-phase fraction and MIB-1 score).

RESULTS

TSS was 92%, 81.1% and 40.1% for pT1a, pT1b and pT2, respectively (p <0.05). TSS according to DNA ploidy status (diploid vs aneuploid) was pT1a-95.2% vs 68.6% (p <0.05), pT1b-90% vs 46.7% (p <0.05) and pT2-49.2% vs 25% (p not significant). DNA ploidy was also significantly associated with survival when adjusted for NG. There was no significant association between TSS and MIB-1 score or tumor S-phase fraction.

CONCLUSIONS

The 2002 TNM classification is a useful prognostic factor for evaluating organ confined RCC of the clear cell subtype. Evaluation of the DNA content in clear cell RCC appears to significantly improve the predictive value of the TNM staging system, especially in the pT1a and pT1b categories. Fuhrman NG alone or combined should be routinely used in such patients.

Prognostic significance of clinicopathologic and deoxyribonucleic acid flow cytometric variables in non-metastatic renal cell carcinoma in the modern era

OBJECTIVE

The prognostic value of deoxyribonucleic acid (DNA) ploidy in renal cell carcinoma (RCC) is not well-defined among modern surgical nephrectomy series. We sought to determine which variables correlated with overall survival and recurrence-free survival in the modern era.

METHODS

We reviewed all patients from 1992 to 2000, who prospectively had DNA ploidy analysis of their primary tumor determined at the time of nephrectomy for nonmetastatic RCC. Variables examined included age, gender, ethnicity, presentation (incidental vs. symptomatic), preoperative laboratory studies, American Society for Anesthesiology class, tumor size, tumor-nodes-metastasis stage, histology, Fuhrman grade, and diploid versus nondiploid tumor. Statistical analyses of overall survival and recurrence-free survival were performed using the Kaplan-Meier method, log-rank test, and Cox regression model using commercially available software.

RESULTS

Sixty men and 41 women, median age 61 years (range, 23-85), were included. Pathologic stage included T1 (54 patients), T2 (14), and T3 (33). Eighty-four patients had conventional RCC. A total of 58 patients had well-differentiated (Fuhrman Grade 1 [12] or Grade 2 [46]), 28 had moderately differentiated (Grade 3), 12 had poorly differentiated tumors (Grade 4), and 3 were not specified. There were 52 patients who had diploid tumors, and 49 had aneuploid tumors. Median follow-up was 39 months (range, 0-109). Actuarial 5-year overall survival was 70%, and 5-year recurrence-free survival was 76%. Diploid tumors were significantly associated with better recurrence-free survival (P = 0.02) but not overall survival (P = 0.17). On multivariate analysis, the American Society for Anesthesiology class (P = 0.01), abnormal preoperative platelet count (P = 0.03), and tumor differentiation (P = 0.01) were independent predictors of overall survival, whereas only tumor differentiation (P = 0.05) was an independent predictor of recurrence-free survival.

CONCLUSIONS

In the modern era, DNA ploidy is not an independent predictor of either overall survival or recurrence-free survival in patients with nonmetastatic RCC. The most important predictor of recurrence-free survival is tumor differentiation.

Allelic loss of 3p25 associated with alterations of 5q22.3 approximately q23.2 may affect the prognosis of conventional renal cell carcinoma

Little is known about the clinical significance at the frequent association of 3p loss with 5q gain/loss in conventional renal cell carcinoma (RCC). We analyzed the clinical significance of copy number gain and loss at 5q21 approximately q23 combined with allelic loss of 3p25 (including the VHL gene). Fifty RCCs were examined by dual-color fluorescence in situ hybridization with DNA probes for D3Z1 (3cen), cCI3-865 (3p25.1 approximately p25.3), D5S23 (5p15.2), cCI5-243 (5q21.2 approximately q21.3), and cCI5-215 (5q22.3 approximately q23.2). In patients who had 3p loss, there was a significant association of loss at 5q22.3 approximately q23.2 with large tumors (>7 cm) and high-grade tumors (both P < 0.05), whereas gain at 5q22.3 approximately q23.2 was associated with low-grade tumors (P < 0.05). There was also a significant association loss at 5q21.2 approximately q21.3 high-grade tumors in patients with 3p loss (P < 0.05). Patients with 3p loss and gain at 5q22.3 approximately q23.2 had a significantly better disease-specific survival than those who had 3p loss without such gain (P < 0.05). Allelic loss of 3p25 including the VHL gene is thought to be an immediate event in the development of conventional RCC. Copy number gains or losses of 5q21 approximately q23 are thought to be events that lead to tumor progression although the clinical significance of either gains or losses is not well known.

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.

The superior prognostic value of humoral factors compared with molecular proliferation markers in renal cell carcinoma

BACKGROUND

The American Joint Committee on Cancer and the Union Internationale Contre le Cancer have acknowledged routine laboratory parameters, such as serum calcium, alkaline phosphatase, hemoglobin, and the erythrocyte sedimentation rate (ESR), as predictors of survival in patients with renal cell carcinoma. The predictive value of these parameters compared with proliferation markers, such as Ki-67, proliferating cell nuclear antigen (PCNA), topoisomerase II-alpha, and p100, has not been determined.

METHODS

Forty-eight consecutive patients who underwent nephrectomy for nonmetastatic renal cell carcinoma between 1990 and 1994 were observed up to 120 months postoperatively. Ten of 48 patients developed tumor progression 6-69 months after surgery. Routine preoperative laboratory parameters as well as tumor-specific data were assessed. Findings were compared with tumor proliferation indices, which were obtained by immunohistochemical staining for nuclear antigens Ki-67, PCNA, topoisomerase II-alpha, and p100 in paraffin embedded tumor tissue.

RESULTS

Univariate and multivariate statistical analyses demonstrated superiority of routine laboratory values compared with tumor proliferation indices in predicting progression-free survival and disease-specific death. The best predictor after tumor size and symptomatic presentation was ESR (P < 0.0001), with ESR values > 70 mm at 2 hours indicating a significantly poorer prognosis. Only the proliferation marker Ki-67 reached univariate significance at a threshold of 7%.

CONCLUSIONS

Routine laboratory parameters, such as alkaline phosphatase, lactate dehydrogenase, thrombocyte count, and especially ESR, provided superior long-term prognostic information for patients with nonmetastatic renal cell carcinoma compared with the molecular tumor proliferation markers Ki-67, PCNA, topoisomerase II-alpha, and p100.

Chromophobe renal cell carcinoma

BACKGROUND

Chromophobe renal cell carcinoma (CRCC) is often associated with a favorable prognosis. However, to the authors' knowledge, only few clinical data are available regarding this variant of tumor. In the current study, the authors report their experience with CRCC over the last 14 years.

METHODS

Since 1989, 61 patients have been treated at the study institution for CRCC. Tumor characteristics and patient outcome were analyzed retrospectively. Data were obtained from the patients' medical records.

RESULTS

The mean age of the patients was 58 years. Of the 61 tumors, 68.8% were discovered incidentally. The mean tumor size was 6.9 cm. Fifty-seven patients (93.4%) were treated with radical nephrectomy and 4 patients (6.6%) underwent partial nephrectomy. According to the 1997 TNM classification, the pathologic tumor stage was T1 in 65.6% of cases, T2 in 31.1% of cases, and T3a in 3.3% of cases. All tumors were staged as N0M0. Nuclear grade was low (1 or 2) in 88.5% of cases. In no case of CRCC was a sarcomatoid component observed. At a mean follow-up of 49.5 months (range, 5-135 months), no patient had experienced tumor recurrence or disease progression, and none had died of renal carcinoma.

CONCLUSIONS

In the authors' experience, CRCC carries an excellent prognosis, possibly due to the high rate of low-stage and low-grade tumors.

Long-term results of nephron-sparing surgery for renal cell carcinoma in 114 patients: risk factors for progressive disease

OBJECTIVES

To evaluate risk factors for metastatic disease after nephron-sparing surgery (NSS) for renal cell carcinoma (RCC).

PATIENTS AND METHODS

NSS for RCC was used 117 times in 114 patients at our institution; 61 had a normal contralateral kidney and were selected for elective NSS, and in 56 cases (53 patients) the indication for NSS was imperative. Univariate and multiple regression analysis was used to evaluate the risk factors for metastatic disease.

RESULTS

After a mean follow-up of 80 months, there was tumour progression in 17 of the 114 patients (15%). In the univariate analysis, the tumour diameter (P = 0.03) and imperative indication (P = 0.009), and in multiple regression analysis only imperative indication, were significant risk factors for metastatic disease (P = 0.016).

CONCLUSIONS

Elective NSS for RCC provides excellent long-term results in selected patients, whereas those undergoing NSS imperatively are at a significantly higher risk of metastatic disease and require a close follow-up.

Prognostic factors in renal cell carcinoma

Several well-established prognostic factors are now available for RCC and have proven utility for patient counseling and management. Consideration of these factors allows for a rational stratification of patients into clinical trials and facilitates the comparison of reports from diverse institutions. Tumor stage remains the most important prognostic factor for RCC, but compelling data have also been accumulated in support of various clinical signs and symptoms, tumor grade, size, histologic subtype, and DNA content and nuclear morphometry. Novel efforts to integrate these factors show great promise and are likely to incorporate molecular factors in the near future.

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.

Clinical significance of allelic loss of chromosome region 5q22.3 approximately q23.2 in nonpapillary renal cell carcinoma

To analyze the clinical significance of copy number gain and loss at chromosome region 5q21 approximately q23, 105 nonpapillary renal cell carcinomas (RCC) were examined by interphase cytogenetic analysis using the dual-color fluorescence in situ hybridization (FISH) technique. DNA probes for D5S23 (5p15.2), cCI5-243 (5q21.2 approximately q21.3), and cCI5-215 (5q22.3 approximately q23.2) were used, and the signals for cCI5-243 and cCI5-215 were compared with those for D5S23 as the numerical control. Aneusomy (three or more copies) of chromosome 5 was found in 22 tumors (21.0%). Aneusomy was significantly correlated with loss at 5q21 approximately q23, while disomy with gain at 5q21 approximately q23 (P<0.05). Aneusomy was also significantly related to poor disease-specific survival (P<0.01). Gain and loss at cCI5-243 were seen in 34 (32.4%) and 59 (56.2%) tumors, respectively, while gain and loss at cCI5-215 occurred in 55 (52.4%) and 45 (42.9%) cases, respectively. The frequency of gain at cCI5-215 was significantly correlated with a smaller tumor diameter (7 cm or less, P<0.05), while loss with a larger one (>7 cm, P<0.05). Both loss at cCI5-215 and aneusomy of chromosome 5 were significantly related to poor disease-specific survival (P<0.05). In conclusion, alterations of chromosome 5 (including allelic loss of 5q22.3 approximately q23.2) could be a useful genetic marker for predicting the patient prognosis of RCC.

Prognostic value of nuclear grading in patients with intracapsular (pT1-pT2) renal cell carcinoma. Long-term analysis in 213 patients

BACKGROUND

The TNM classification system considers tumor size and, in particular tumor, greatest dimension as the only prognostic indicator for intracapsular renal cell carcinoma (RCC). The objective of the current study was to evaluate the role of nuclear grading and its importance as a prognostic indicator in patients with intracapsular (T1-T2) RCC.

METHODS

A retrospective study was performed on 213 patients with RCC limited to the kidney who were free from distant metastases at the time of diagnosis and who underwent radical nephrectomy from January 1990 to November 1999. All patients were staged according to the 1997 TNM classification system. Nuclear grading was determined according to the criteria proposed by Fuhrman et al. The patients' status was evaluated last in November 2000. The mean follow-up was 52 months (range, 12-130 months). The probability of survival was estimated by using the Kaplan-Meier method, with the long-rank test used to estimate differences among levels of the analyzed variables. A multivariate Cox proportional hazards model was performed to estimate the relative importance of the variables in predicting survival.

RESULTS

The 5-year disease specific survival rates for patients with pT1 and pT2 tumors were 93.5% and 61.1%, respectively. The 5-year disease specific survival rates for patients with Grade 1, Grade 2, and Grade 3-4 tumors were 95.9%, 86.8%, and 60.1%, respectively. A comparison of the survival curves both by stage and grade showed a statistically significant difference. For patients with pT1 lesions, the 5-year disease specific survival rate was 94.2% for patients with Grade 1-2 disease and 89.8% for patients with Grade 3-4 disease. For patients with pT2 lesions, the 5-year disease specific survival rate was 72.2% for patients with Grade 1-2 disease and 20% for patients with Grade 3-4 disease.

CONCLUSIONS

Within intracapsular tumors that measure > 7.0 cm in greatest dimension, nuclear grade is an important morphologic variable for predicting long-term survival. Identification of patients with nuclear Grade 3-4 tumors is important prognostically to determine the metastatic potential of pT2 tumors, because this subgroup of patients may benefit from adjuvant immunotherapy.

Proliferative activity of renal cell carcinoma associated with acquired cystic disease of the kidney: comparison with typical renal cell carcinoma

To assess the proliferative activity of renal cell carcinoma (RCC-A) in patients with acquired cystic disease of the kidney (ACDK) after long-term hemodialysis, we analyzed cell cycle, DNA ploidy, and S-phase fraction by flow cytometry (FCM) and proliferating cell nuclear antigen (PCNA) labeling index by immunohistochemistry. The data were compared with those of typical RCC (tRCC). Sixteen (88.9%) of 18 RCC-As showed a diploid pattern. The values of cells at each phase in the cell cycle in RCC-A group (S, 4.36% + 2.16%; G2M, 5.06% + 1.90%; S+G2M, 9.41% + 2.81%; P <.05) were significantly different from those of tRCCs (S, 8.91% + 6.58%; G2M, 8.77% + 5.73%; S+G2M; 17.67% + 7.61%). The PCNA labeling index was statistically significantly lower in the RCC-As (24.01% +/- 13.4%; P <.05) than in tRCCs (42.27% +/- 26.1%). These results indicate that the RCC-As are less proliferative than tRCC and are consistent with the observation that RCC-As are less aggressive neoplasms.

Prognostic factors and molecular markers for renal cell carcinoma

Renal cell carcinoma is the most common cancer in the kidney, affecting nearly 30,000 Americans every year and is associated with over 12,000 deaths annually. If detected early, renal cell carcinomas can be cured surgically. However, once metastatic disease develops the prognosis for long-term survival is poor. Unfortunately, one-third of patients have metastatic disease at the time of diagnosis and approximately 50% of the patients undergoing surgical resection for less advanced disease eventually relapse. This review examines the clinical and molecular prognostic tools currently available or under investigation for kidney cancer.