Prognostic factors of renal cell carcinoma

A comparison of the vascular density of VEGF expression with microvascular density determined with CD34 and CD31 staining and conventional prognostic markers in renal cell carcinoma

AIM

The aim of this study was to compare the vascular density of Vascular endothelial growth factor (VEGF) expression with microvascular density determined by CD34 and CD31 with conventional prognostic parameters.

METHODS

The study involved 50 renal cell carcinoma (RCC) cases. VEGF, CD34, and CD31 were stained by immunohistochemistry, and then preparations were evaluated by two pathologists under light microscopy. The whole tumor area was scrutinized in all the sections. In the evaluation of VEGF, due to the lack of homogenous staining within the tumor, two parameters, distribution and intensity of expression, were evaluated semiquantitively. In the evaluation of microvascular density with CD34 and CD31 staining, three hot areas with the highest density were determined. In x200 magnification of these areas, on a single plane, the quantity of vascular structures with lumens was determined.

RESULTS

Intensity of VEGF Expression was higher in papillary type carcinoma of kidney parenchyma (P = 0.014) and it was significantly correlated with tumor stage (P = 0.013), survival time (P = 0.01), and tumor size (P = 0.035). Distribution of VEGF expression was also higher in papillary RCC (P = 0.055) and it was significantly correlated with tumor stage (P = 0.043) and tumor size (P = 0.039). Vascular density determined with CD34 staining was higher in conventional RCC (P < 0.05); in addition, it was significantly correlated with distribution and intensity of VEGF expression (P < 0.05) and tumor stage (P < 0.05). Vascular density determined with CD31 staining was not significantly correlated with tumor type, tumor stage, nuclear grade, and survival time.

CONCLUSIONS

Intensity and distribution of VEGF were higher in papillary RCC. Both parameters were significantly correlated with tumor size, stage, and vascular density determined with CD34 staining. Intensity of VEGF was also significantly correlated with capsule invasion. Vascular density determined with CD34 staining, however, was higher in conventional RCC, and it was correlated with tumor size and stage.

Prognostic significance of multidrug-resistance protein (MDR-1) in renal clear cell carcinomas: a five year follow-up analysis

Background

A large number of renal cancer patients shows poor or partial response to chemotherapy and the mechanisms have not been still understood. Multi-drug resistance is the principal mechanism by which many cancers develop resistance to chemotherapic drugs. The role of the multi-drug resistant transporter (MDR-1/P-glycoprotein), the gene product of MDR-1, and that one of the so-called multi-drug resistance associated protein (MRP), two energy-dependent efflux pumps, are commonly known to confer drug resistance.

We studied MDR-1 expression in selected cases of renal cell carcinoma (RCC), clear cell type, with long-term follow-up, in order to establish its prognostic role and its possible contribution in the choice of post-surgical therapy.

Methods

MDR-1 has been studied by standard LSAB-HRP immunohistochemical technique, in paraffin embedded RCC samples. Protein expression has been compared to clinical and histopathological data and to disease specific survival of RCC patients, by Kaplan-Meier curve and Cox multivariate regression analyses.

Results

Two groups of RCCs were obtained by esteeming MDR-1 expression and disease specific survival (obtained with Kaplan-Meier curve and Cox multivariate regression analyses): the first one presents low or absent MDR-1 expression and good survival; the second one is characterized by high MDR-1 expression and significant poor outcome (p < 0.05). Afterwards, we have found disease specific survival, adjusted for stages and independent of therapy: this difference of survival rates was statistically significant (p < 0.05). Stage adjusted disease specific survival rate, according to MDR-1 expression and therapy in patients affected by RCC in early stage (stage I), has revealed that the group of patients with high MDR-1 expression and without adjuvant therapy showed poor survival (p < 0.05). Cox multivariate regression analysis has confirmed that, in our cohort of RCC (clear cell type) patients, the strong association between MDR-1 and worse outcome is independent not only of the adjuvant therapy, but also of the other prognostic parameters (p < 0.05).

Conclusion

In our opinion, the results of this study well prove the relationship between MDR-1 expression and worse clinical prognosis in RCC, because MDR-1 over-expressing RCCs can be considered a group of tumours with a more aggressive behavior. This finding outlines a possible role of MDR-1 as prognostic factor, dependent and independent of multidrug resistance. These results could be useful to predict cancer evolution and to choose the appropriate treatment: this is another step that can stimulate further promising and interesting investigations on broader study population.

Low predictive accuracy of the Kattan postoperative nomogram for renal cell carcinoma recurrence in a population of French patients

BACKGROUND

The aim of the current study was to establish the predictive accuracy of the Kattan postoperative nomogram for nonmetastatic renal cell carcinoma (RCC) by comparing predictions with actual disease recurrence in patients who underwent surgery in a single center in France.

METHODS

Between 1985 and 2000, 844 patients were treated for RCC. The following data were collated: age, symptoms, histology, tumor size, grade, TNM 1997 stage, recurrence, and progression. For each patient a prognostic score (predicted probability) for recurrence-free survival (RFS) at 5 years was calculated using the Kattan nomogram. The discriminating ability of the model was assessed by Harrell's concordance index (c-index). Bootstrapping was used to assess confidence intervals. Furthermore, survival was then estimated by the Kaplan-Meier method and Cox proportional hazards regression analysis.

RESULTS

In all, 565 patients (median age, 62 years) were included. At the time of the last follow-up, 81 patients had died and 101 had experienced RCC recurrence. The c-index for RFS (Kattan nomogram) was only 0.607 (95% confidence interval [CI]: 0.576-0.635). The 5-year RFS rate and cancer-specific survival rate were 81.5% and 84.7%, respectively. Of the 4 variables included in the nomogram, only TNM stage was associated with recurrence in a multivariate analysis (Cox analysis) (P = .022).

CONCLUSIONS

There was a discrepancy between predicted RFS as estimated by the Kattan nomogram and the likelihood of being recurrence-free at 5 years according to the Cox analysis in the current population of patients. However, until new dynamic models become available clinicians may still improve their predictive ability by using the current nomogram.

[Survival analysis for localized renal cell carcinoma. Prognostic value of 1997 TNM classification]

BACKGROUND

The 5th edition of TNM classification for renal cell carcinoma changed the cut-off point of the tumor size for localized tumors, achieving a better distribution of patients with similar survival. Nevertheless, because of the variable evolution of renal cell carcinoma, the prognostic significance of tumor size is questioned as a staging criterion in organ-confined renal cell carcinoma. We analyse renal cell carcinoma specific survival and the prognostic significance of tumor size in I and II stage.

METHODS

We made a retrospective study with 158 renal cell carcinoma surgically treated in our hospital along 12 years. It was created a data base with clinical variables from patient and tumor and analyzed pathological staging, nuclear grade and specific survival, overall stage I and II.

RESULTS

27 renal cell carcinoma were pT1 (17.08%), 52 pT2 (32.91%), 45 pT, (28.45%), 10 pT3B (6.32%), y 24 pT4 (15.18%). The specific survival at 5 years for pT1-pT2, I-II stage, was 100% and 94% respectively, and no statistic significant differences were found between stage I and II (log-rank test 0.53, p>0.05). The specific survival at 5 years for pT3a, pT3B, y pT4 was 76.5%, 66.6% y 38.4%. There was a significant difference in survival in accordance with the tumor location, intrarenal (T1 y T2) versus extrarenal (T3A, T3B, T4) (log-rank test 9.06, p< 0.05). According to nuclear grade we don't find significant differences for pT1 y pT2 (Fisher test, p=1). Regarding the relation between pT stage and nuclear grade of the tumor we obtained a chi-square inear tendency of 38.19, p<0.001.

CONCLUSION

The differences in the evolution of the organ-confined renal cell carcinoma with respect to the tumor size may be due to other molecular and biological variables, probably associated with stage, not controlled in essays. The TNM classification for organ-confined renal cell carcinoma based in tumor size seems artificial. New revisions of the classification system are necessary to identify which organ-confined carcinoma will have unfavourable evolution and to include them in a different category.

Biologic significance of fascin expression in clear cell renal cell carcinoma: systematic analysis of primary and metastatic tumor tissues using a tissue microarray technique

OBJECTIVES

To investigate the biologic significance of fascin, a globular actin cross-linking protein, involved in cell adhesion and motility, in primary and metastatic renal cell carcinoma (RCC).

METHODS

A total of 136 primary clear cell RCCs and 54 clear cell RCC metastases were stained immunohistochemically using a tissue microarray technique. Distinct cytoplasmic staining was considered positive, and the staining results were associated with the pT stage, Fuhrman grade, tumor size, sarcomatoid morphology, and metastasis-free survival. For multivariate testing, Cox's proportional hazards regression model was used.

RESULTS

Fascin expression was noted in 13 (10%) of 136 primary and 25 (46%) of 54 metastatic RCC specimens (P <0.001). Fascin expression was associated with high tumor stage (2 [3%] of 70 pT1 versus 11 [17%] of pT2/pT3; P = 0.008), high tumor grade (3 [3%] of 88 grade 1-2 versus 10 [21%] of 48 grade 3-4; P = 0.002), and large tumor size (P <0.001). In addition, 8 (62%) of 13 RCCs with sarcomatoid morphology expressed fascin compared with 5 (4%) of 123 RCCs without sarcomatoid transformation (P <0.001). Metastatic disease was noted in 10 (77%) of 13 patients with fascin-positive RCC compared with 26 (21%) of 121 patients with fascin-negative RCC (P <0.001). Multivariate analysis revealed pT Stage 1 or greater (P <0.001, risk ratio [RR] 8.6, 95% confidence interval [CI] 2.8 to 26.5), Fuhrman grade greater than 2 (P <0.001, RR 12.7, 95% CI 4.6 to 35.4), fascin expression (P <0.001, RR 7.2, 95% CI 3.0 to 17.4), and female gender (P = 0.02, RR 2.5, 95% CI 1.1 to 5.5) as independent predictors of metastatic disease.

CONCLUSIONS

Fascin immunoreactivity in RCC proved to be an independent predictor of metastatic disease and was demonstrated in almost one half of RCC metastases. Thus, fascin may be a promising molecular target for future cancer therapy.

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.

Matrix metalloproteinase-9 polymorphisms and renal cell carcinoma in a Japanese population

Matrix metalloproteinase-9 (MMP-9) plays a pivotal role in cancer invasion and metastasis. Recently, experimental study has shown that MMP-9 is also implicated in early carcinogenesis. We hypothesized that MMP-9 polymorphisms influence the predisposition to develop renal cell carcinoma (RCC). To test the hypothesis, we determined MMP-9 C-1562T and R279Q genotypes in Japanese RCC cases (n=179) and controls (n=211). Furthermore, we investigated the relationship between MMP-9 polymorphisms and clinicopathological features. The distribution of C-1562T and R279Q genotypes was not significantly associated with the risk of RCC (odds ratio [OR]=1.14, 95% confidence interval [CI]=0.73-1.77 for -1562 CT/TT genotypes versus CC genotype; OR=1.29, 95% CI=0.86-1.93 for 279 RQ/QQ genotypes versus RR genotype). However, the distribution of R279Q genotypes was significantly associated with the histological grade (P<0.01). The present results suggest that MMP9 R279Q polymorphism has influence on the malignant potential of RCC.

Histological Subtyping and Nuclear Grading of Renal Cell Carcinoma and Their Implications for Survival: A Retrospective Nation-Wide Study of 629 Patients

OBJECTS

The aim of this study was to evaluate the prognostic significance of the current WHO histological subtyping and Fuhrman nuclear grading on the survival of patients with renal cell carcinoma (RCC).

MATERIALS AND METHODS

A retrospective population-based study was carried out on all patients with a histopathologically confirmed diagnosis of RCC in Iceland between 1971 and 2000. Fuhrman grade, TNM stage, and survival were evaluated and multivariate analysis applied in order to determine prognostic factors.

RESULTS

Out of 629 patients (387 males, 242 females, mean age 64 years), 558 (88.7%) had clear cell, 53 (8.4%) papillary, and 13 (2.1%) chromophobe RCC. Patient demographics were comparable for the two major subtypes, but chromophobe RCCs were larger in size and were diagnosed at a younger age. Clear cell RCCs were more often of higher grades (G3+G4, 48.4%) and at advanced TNM stages (III+IV, 59.3%) than papillary RCCs (22.6% and 34% respectively, p<0.001). Linear regression analysis showed a strong correlation between grade, tumor size, and stage (p<0.001). Chromophobe RCCs had a better survival in univariate analysis than both papillary and clear cell RCCs (84.6% vs. 66.5% and 54.9% 5-year disease specific survival, p<0.001). However, in the multivariate analysis, only the patient's age, calendar year of diagnosis, TNM stage, and nuclear grade were independent prognostic factors of survival.

CONCLUSION

In this complete nation-wide series nuclear grading is important in predicting survival of patients with RCC. It is strongly related to both tumor size and stage, with stage being by far the strongest prognostic factor. Different histological subtypes confer different survival. However, in spite of the distinctive cytogenetic and molecular characteristics of the subtypes, the survival difference is to a large extent due to differences in grade and particularly stage.

Mcm2, Geminin, and KI67 define proliferative state and are prognostic markers in renal cell carcinoma

PURPOSE

The origin licensing factors minichromosome maintenance 2 (Mcm2) and Geminin have recently been identified as critical regulators of growth and differentiation. Here we have investigated the regulation of these licensing factors together with Ki67 to further elucidate the cell cycle kinetics of renal cell carcinoma (RCC). Furthermore, we have examined the role of Ki67, Mcm2, and Geminin in disease-free survival after nephrectomy in patients with localized RCC.

EXPERIMENTAL DESIGN

Tissue sections from 176 radical nephrectomy specimens were immunohistochemically stained with Mcm2, Geminin, and Ki67 antibodies. Labeling indices (LI) for these markers were compared with clinicopathologic parameters (median follow-up 44 months).

RESULTS

In RCC, Mcm2 is expressed at much higher levels than Ki-67 and Geminin, respectively [medians 41.6%, 7.3%, and 3.5% (P < 0.001)] and was most closely linked to tumor grade (P < 0.001). For each marker, Kaplan-Meier survival curves provided strong evidence that increased expression is associated with reduced disease-free survival time (P < 0.001). Additionally, an Mcm2-Ki67 LI identified a unique licensed but nonproliferating population of tumor cells that increased significantly with tumor grade (P = 0.004) and was also of prognostic value (P = 0.01). On multivariate analysis, grade, vascular invasion, capsular invasion, Ki67 LI >12%, and age were found to be independent prognostic markers.

CONCLUSIONS

Although Ki67 is identified as an independent prognostic marker, semiquantitative assessment is difficult due to the very low proliferative fraction identified by this marker. In contrast, Mcm2 identifies an increased growth fraction that is closely linked to grade, provides prognostic information, and is amenable to semiquantitative analysis in routine pathologic assessment.

Correlation of bFGF expression in renal cell cancer with clinical and histopathological features by tissue microarray analysis and measurement of serum levels

The prognostic value of bFGF for surgically treated renal cell cancer (RCC) patients was evaluated by immunohistochemistry (IHC) and the tissue microarray technique (TMA). Additionally, preoperative serum bFGF levels were correlated to tumour stage and the presence of metastases at initial diagnosis. Serum levels of bFGF were measured by ELISA in 39 healthy volunteers, in 37 patients with benign urologic diseases and in 74 RCC patients, 26 of whom revealed lymph node or distant metastases. bFGF expression as detected by IHC was investigated in 777 tissue cores from 259 different RCC patients [median follow-up: 138 (36-240) months]. Eighty eight patients died from tumour progression. For each patient, the TMA slides contained a tissue core from the primary tumour, its invasion front and the normal renal parenchyma. bFGF serum levels were higher in RCC patients vs healthy volunteers (P<0.01) and vs patients with benign urologic diseases (P<0.01). Metastasized patients revealed higher bFGF serum levels than organ-confined specimens (P<0.01). As detected by IHC only increased bFGF expression in the invasion front tissue correlated with the patients' long-term survival (log rank test) (P=0.03). In multivariate analysis regional LN metastases (P<0.01), the histological grading (P<0.01), and an increased bFGF expression in the invasion front (P=0.04) independently predicted the patients' clinical prognosis. Not the expression of bFGF in the primary tumour but in its invasion front reflects the aggressiveness of RCC, hereby indicating a different biological potential within both areas. The value of bFGF serum levels as indicators of systemic tumour dissemination remains to be determined.

A phase-II study of pegylated interferon alfa-2b for patients with metastatic renal cell carcinoma and removal of the primary tumor

Twenty-two patients with metastatic renal cell carcinoma and removal of the primary tumor were treated with subcutaneous pegylated interferon alfa-2b (PEG-Intron) to evaluate toxicity and efficacy. Start dose was 3.0 microg/kg/week, escalated to 6.0 microg/kg/week. After 2 months, therapy was extended in case of response or stable disease (SD) until progressive disease (PD) or relapse for a maximum of 2 years. National Cancer Institute common toxicity criteria (NCI-CTC) were monitored every 2-4 weeks. After 2 months, nine patients did not continue (8 PD, 1 SD with grade 4 CTC) and 13 extended treatment [three partial response (PR), 10 SD], of these, 11 progressed. One patient with PR developed a durable complete response later. Overall response rate was 13.6% (3/22). Median overall survival is 13 months (range 3-35 months). Dosage was escalated to 6 microg/kg/week in three patients. NCI-CTC grade 2 and 3 required dose attenuation in 12 patients during escalation, and reduction in 10 during the trial. Three patients discontinued because of grade 4 CTC (two fatigue, one hyperglycemia). Fatigue was the major dose-limiting toxicity. These results suggest an efficacy and toxicity of PEG-Intron comparable to standard interferon alfa-2b in patients with mRCC and removal of the primary tumor.

Biochemical and molecular markers in renal cell carcinoma: an update and future prospects

Cancer is a big problem in the developed world as well as in developing countries. Renal cell carcinoma (RCC) accounts for approximately 3% of adult malignancies and 90-95% of neoplasms arising from the kidney. RCC is more common in men than in women (2:1), and it most often occurs in patients between the ages of 50-70 years. In all cancers the cancerous cells release particular kind of proteins (called tumour markers) and blood tests are used to detect the presence of these markers. These tumour markers nowadays are an area of interest for oncologists who search for a possible solution in the detection and treatment of RCC. Different kinds of biochemical and molecular markers such as ferritin, MN/CA9, apoptotic index, p53, IL-2, gamma-enolase, CD44, CD95, chromosome instability and loss of heterozygosity have been tested in RCC, but so far no marker fulfils one or the other criteria to be considered as an ideal marker for RCC. This review gives basic and updated information about the different kinds of biomarkers studied in RCC and about the role implementation of genomics and proteomics in RCC.

[Local relapse and single site of metastatic involvement of renal tumour. Prognostic factors and survival]

OBJECTIVE

To evaluate the clinical and pathological characteristics and survival in patients surgically treated for renal tumours that had local recurrence or metastasis to a single site.

MATERIAL AND METHODS

A retrospective study of 321 nephrectomies, evaluating the clinical and pathological variables in patients having local recurrence or metastasis to a single site, and who were treated surgically. Study and comparison of survival in the different groups.

RESULTS

The only factor found to have an independent influence on local recurrence is pathological stage. Local recurrence and the presence of metastasis to a single site have similar survival rates, both being statistically worse than in patients without metastasis at diagnosis, but better than in those having metastasis at diagnosis.

CONCLUSIONS

The presence of local recurrence has the same prognosis as a single excisable metastatic site, the prognosis being better than those initially with metastasis subjected to nephrectomy before receiving systemic treatment.

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.

Cystic renal cell carcinoma: biology and clinical behavior

The purpose of the study was to evaluate unilocular and multilocular cystic renal cell carcinoma (cRCC). These tumors are a rare entity, comprising approximately 1 to 2% of all renal tumors, and their true biologic behavior is not well-known. Initial review of renal cell carcinoma (RCC) cases treated at our institution between 1989 and 2001 identified 39 cases of cRCC. However, histopathologic review of these cases by 2 pathologists revealed that only 18 cases met the criteria that all tumors have a cystic component that constitutes at least 75% of the total lesion without evidence of necrosis. These cases were compared to 614 conventional clear cell RCC cases with regards to clinical outcomes. All 18 patients presented with localized (N0M0) disease. Thirteen (72%) of the tumors were Fuhrman Grade 1, while the remaining 5 (28%) were Fuhrman Grade 2. By comparison, only 60% of the clear cell RCC tumors were Grade 1 or 2. Similarly, 83% of cRCC were pT1 tumors compared to only 35% of conventional clear cell tumors. Mean tumor size for the cRCC tumors was 4.9 cm compared to 7.4 cm for conventional clear cell tumors. Cystic RCC patients had an 82% four-year disease-specific survival (DSS). Unilocular and multilocular cRCC is a distinct subtype of clear cell RCC. Its biology appears to be more favorable with regards to important prognostic factors such as metastatic presentation, Fuhrman grade, 1997 T stage, and tumor size. These findings suggest that cRCC patients may benefit from nephron sparing surgery.

Feocromocitoma con trombo en cava

Pheochromocytoma, a paraganglioma of suprarenal location, is a catecholamine-secreting chromaffin cell tumour. Spread of these tumours to the vena cava is rare and the thrombus only reaches the right atrium in exceptional cases. We present the case of a patient who, without previous symptomatology, presented with a clinical picture of multiorganic dysfunction with primary manifestation of a suprarenal tumour with vascular spread to the right atrium affecting the right suprahepatic vein.

Biological significance of p27 and Skp2 expression in renal cell carcinoma. A systematic analysis of primary and metastatic tumour tissues using a tissue microarray technique

p27 (p27/kip1) is involved in cell-cycle control, and loss of p27 expression may result in tumour development and/or progression. Association with Skp2 targets p27 for degradation. Using a tissue microarray technique, 171 primary renal cell carcinomas (RCCs) and 58 RCC metastases were immunostained for p27 and Skp2. p27 Immunoreactivity was noted in 83 of 129 (64%) clear cell, 6 of 22 (27%) chromophobe and 15 of 20 (75%) papillary tumours as well as 44 of 58 (76%) metastases. In clear cell cancers, high p27 expression (> or =50% of tumour cells) decreased with rising tumour stage (50% pT1/pT2 versus 20% pT3; P<0.001) and grade (44% G1/G2 versus 21% G3/G4; P=0.008). None of 22 chromophobe cancers showed high expression in contrast to 46 of 129 (36%) clear cell tumours (P<0.001). Skp2 expression was noted in 8 of 129 (6%) clear cell cancers and 11 of 55 (20%) metastases (P=0.008). Immunoreactivity increased with rising tumour stage (1% pT1/pT2 versus 11% pT3; P=0.03) and grade (1% G1/G2 versus 15% G3/G4; P=0.004) and was associated with sarcomatoid morphology (P<0.001). In multivariate analysis, patients with low p27 expression and Skp2 immunoreactivity in clear cell cancers had a less favourable outcome. In conclusion, p27 and Skp2 proved to be additional biomarkers in renal cancer pathology with both prognostic and diagnostic impact.

Evaluation of patients referred for percutaneous ablation of renal tumors: importance of a preprocedural diagnosis

OBJECTIVE

Percutaneous ablation of renal cell carcinoma has the potential to be as effective as partial nephrectomy. Because the entire tumor cannot be examined at pathology, diagnosis relies solely on imaging and percutaneous biopsy. Diagnoses of cancer have been rendered using imaging alone in some clinical trials of percutaneous ablation. If these trials inadvertently included benign masses, the efficacy of ablation was overestimated. Therefore, we sought to determine the prevalence of benign masses in a population of patients referred for percutaneous tumor ablation of presumed renal cell carcinoma.

SUBJECTS AND METHODS

Twenty-seven patients were referred by urologists for MRI-guided cryotherapy of suspected renal cell carcinoma. Renal masses ranged from 1.0 to 4.6 cm (mean, 2.2 cm) in diameter. The CT, MRI, and percutaneous biopsy findings were tabulated and compared with surgical and imaging follow-up.

RESULTS

Ten patients (37%) had a benign renal mass, including three angiomyolipomas, that had no evidence of fat on CT or MRI. Three masses were proven benign by biopsy, three by imaging, and four by a combination of biopsy and imaging. The masses in the remaining 17 patients were ablated. Biopsy revealed malignant cells in 10, suspicious cells in four, and atypical cells in two; one was nondiagnostic.

CONCLUSION

A substantial percentage of patients referred for percutaneous ablation of renal tumors had benign masses. If CT or MRI alone cannot be used to diagnose a benign entity, patients should undergo a biopsy before the treatment session.

Basic science and research in renal cell carcinoma: from workbench to bedside

PURPOSE OF REVIEW

Renal cell carcinoma represents the third most common cancer in men. Radical surgery remains the only curative approach, and the 5-year survival rate once the cancer has metastasized rarely exceeds 20% despite systemic therapy. It becomes evident that an improvement in outcome might only be achieved if (1) there is early diagnosis, (2) there is accurate prediction of progression and response, and (3) new treatment options reflecting the molecular pathogenesis and progression are developed.

RECENT FINDINGS

The detection of circulating cancer cells by reverse transcriptase/polymerase chain reaction techniques for the MN/CAIX gene, the identification of specific genetic alterations in circulating tumor DNA, as well as the demonstration of somatic von Hippel-Lindau mutations and extracellular matrix proteins in urine of high-risk patients might be clinically useful in improving early diagnosis and treatment. The signal transducer and activator of transcription has been shown to significantly correlate with relapse patterns following radical surgery. Heterozygosity or homozygosity for class II haplotypes DQA1 and DQB1 accurately predicts response and survival following cytokine-based therapy and may be helpful in patient selection. In terms of treatment, the use of monoclonal antibody derivates against the epidermal growth factor receptor and the vascular endothelial growth factor receptor has shown promising clinical results. Antisense oligodeoxynucleotide therapy has shown significant therapeutic effects in in-vitro and in-vivo studies. Recent developments in the clinical application of proteasome inhibitors have opened the door to exciting, highly specific and effective molecular treatment options for metastatic renal cell carcinoma.

SUMMARY

Recent developments in research on renal cell carcinoma have identified various clinically useful diagnostic and therapeutic options reflecting the molecular basis of the pathogenesis and progression of the disease.

Pathological and molecular biological aspects of the renal epithelial neoplasms, up-to-date

Renal neoplasms are not necessarily high in frequency, but they are characteristic in their heterogeneity and occasional association with systemic familial tumor syndromes and phacomatoses (e.g. clear cell renal cell carcinoma and von Hippel-Lindau disease, Wilms tumor and aniridia, genitourinary malformation and mental retardation (so-called, WAGR syndrome), and angiomyolipoma and tuberous sclerosis). Physicians and pathologists should take note of these syndromes and associated renal neoplasms because they have provided important clues to elucidate the mechanism of tumorigenesis concerning cancer-suppressor genes. This review aims to present recent classification of renal parenchymal neoplasms based on their molecular biological characteristics, and future problems yet to be clarified.

Steroid Hormone Receptor Expression in Renal Cell Carcinoma: An Immunohistochemical Analysis of 182 Tumors

PURPOSE

Steroid hormone receptor expression has an essential role in cancer of the prostate and breast but there is only limited experience with renal cell carcinoma (RCC), especially regarding prognostic and therapeutic impact.

MATERIALS AND METHODS

A total of 188 cases of RCC were stained immunohistochemically for the expression of estrogen (ER), progesterone (PR) and androgen (AR) receptors using a tissue microarray technique. Nuclear steroid hormone receptor immunoreactivities were analyzed semiquantitatively with respect to associations with histological subtype, pT stage, grading and gender using Fisher's exact test. Impact on disease-free survival was analyzed using the Kaplan-Meier method.

RESULTS

Sufficient tumor tissue was present in 182 of the 188 RCCs. AR expression was found in 27 of 182 tumors (14.8%) in 24 male and 3 female patients. AR expression was significantly associated with stage pT1 compared with pT3 (p <0.0001), and grades 1 and 2 compared with grade 3 (p = 0.0005). Regarding progression-free survival, AR positive RCCs showed a significantly better prognosis than AR negative cases (log rank test, p = 0.027). No difference of AR immunoreactivity could be detected between histological subtypes. Only 2 of the 182 cases (1.1%) showed ER and PR immunoreactivity in less than 10% of tumor cell nuclei.

CONCLUSIONS

While ER and PR expression was the exception, AR expression was found in almost 15% of the tumors and it was significantly associated with low stage, well or moderately differentiated tumors and a favorable outcome, decreasing with tumor growth and dedifferentiation. However, these results do not support a potential role of hormonal therapy for metastatic RCC.

Utilidad de marcadores séricos del carcinoma renal

OBJECTIVES

To select a group of useful serum markers in renal cell carcinoma (RCC) with investigational purpose in future.

MATERIAL AND METHODS

Periodic determination in serum of 21 RCC patients of the following markers: EGR, RPC, hemogram and leucocyte differential count (LDC), standard biochemist parameters, beta-2 microglobuline, CEA, CA 12.5, CA 50, CA 15.3, ferritin, interleukin-6, serum interleukin-2 receptor, TNF-alpha and TPSA.

RESULTS

Different elements within the LDC had relations with the presence of symptoms/signs, tumour size, pathological stage and disease progression. There was a significant increase of beta-2 microglobuline and sIL-2 receptor when disease progressed, as well as a similar statistical trend with RPC and alkaline phosphatases. Beta-2 microglobuline and sIL-2 receptor also decreased after treatment of the disease progression.

CONCLUSIONS

We will keep analysing hemogram, LDC and standard byochemics, RPC, ferritin, beta-2 microglobuline and sIL-2 receptor only with investigational purposes, obviating the determination of the rest of the tested markers.

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.

Renal cell carcinoma: new prognostic factors?

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Genomic structure of human OKL38 gene and its differential expression in kidney carcinogenesis

We previously demonstrated the growth inhibitory property of OKL38 and its possible roles in mammary carcinogenesis. To further understand the regulation and roles of OKL38 in tumorigenesis we proceeded to clone and characterize the human OKL38 gene and three of its variants with transcripts of 1.9, 2.2, and 2.4 kb. The human OKL38 gene spans approximately 18 kb and contains 8 exons and 7 introns with exon size ranging from 92 to 1270 bp. RT-PCR and sequence analysis suggest that different transcripts were arrived through differential promoter usage and alternate splicing. Multiple Tissue Expression array (MTE) and Multiple Tissue Northern blot (MTN) indicated that OKL38 was ubiquitously expressed in all tissues with high expression in liver, kidney, and testis. The cancer profiling array (CPA) of paired normal/tumor cDNA showed that OKL38 mRNA was down-regulated in 70% (14 of 20) of kidney tumors. Western analysis revealed that the OKL38 protein was undetectable in 78% (7 of 9 pairs) of kidney tumor tissues. Immunohistological analysis showed that 64% (14 of 22) of kidney tumors were either lost or underexpressed OKL38 protein compared with the adjacent normal tissue. A transfection study using OKL38-eGFP recombinant construct showed that overexpression of the 52 kDa OKL38 protein in A498 cells resulted in growth inhibition and cell death. This study demonstrates the complex genomic structure of the OKL38 gene and its growth inhibitory and cytotoxic properties. Our data suggest the potential use of OKL38 in diagnosis, prognosis, and/or treatment of kidney cancer.