Prognostic factors in renal cell carcinoma

Knockdown of LETM1 inhibits proliferation and metastasis of human renal cell carcinoma cells

The leucine zipper-EF-hand containing transmembrane protein 1 (LETM1) has been reported to serve an important role in a number of human malignancies and is correlated with poor prognosis. However, little is known about the role of LETM1 in renal cell carcinoma (RCC). In the present study, the expression levels of LETM1 were investigated in RCC cell lines (Caki-1, 786-O, OS-RC-2, A498 and ACHN) and the HK-2 normal human renal tubular epithelial cell line. Short interfering RNA (siRNA) was used to knock down the expression of LETM1 in 786-O and A498 cells. The results indicated that the constitutive expression of LETM1 was notably upregulated in RCC cell lines. Knockdown of LETM1 significantly decreased cell proliferation, migration and invasion. Mechanistically, it was revealed that the knockdown of LETM1 expression sharply downregulated the protein expression of β-Catenin, Cyclin D1 and c-Myc in 786-O and A498 cells. In conclusion, these results suggest that knockdown of LETM1 exhibits tumor suppressive effects, at least in part by controlling the downstream Wnt/β-Catenin signaling pathway. Therefore, LETM1 may act as a novel therapeutic target for the treatment of RCC.

Clusterin plays an important role in clear renal cell cancer metastasis

OBJECTIVE

Clusterin (CLU) is implicated in regulating clear renal cell carcinoma (CRCC) progression and metastasis, yet the mechanisms are not elucidated. In the present study, we explored the potential role of CLU in CRCC metastasis.

METHODS

Levels of CLU mRNA and CLU protein were measured by RT-PCR and immunohistochemistry analysis in 22 CRCC with metastasis and 22 without metastasis and 22 samples of normal kidney tissue. After CLU silencing and re-expression, the migration and invasion in vitro and in vivo of Caki-2 cells were determined by wound healing assay, transwell migration assay and pulmonary nodule assay, respectively. The expression of pERK1/2 and MMP-9 were detected by RT-PCR and Western blot assay.

RESULTS

We found a significant increase of CLU and CLU mRNA expression in CRCC, and the expression of CLU is strongly correlated in patients with metastatic disease. We discovered that CLU-rich Caki-2 cells displayed higher invasive ability which prompted us to investigate if CLU silencing could reduce the migration and invasion in Caki-2 cells. Compared with the vector-transfected cells, CLU knocked-down (CLUi) cells showed reduced migration and invasion in vitro, as well as decreased metastatic potential in experimental metastasis. Re-expression of CLU in CLUi cells restored the invasive phenotypes. We found that MMP-9 was downregulated in CLUi cells. We also discovered that levels of activated ERK1/2 correlated with the rich expression of CLU and MMP-9.

CONCLUSION

Our data suggest that CLU may regulate aggressive behavior of human CRCC cells through modulating ERK1/2 signaling and MMP-9 expression.

Vascular endothelial growth factor-targeted therapy for the treatment of renal cell carcinoma

Vascular endothelial growth factor (VEGF)-targeted agents have rapidly been adopted into standard-of-care treatment for renal cell carcinoma (RCC). However, a substantial proportion of patients fail to respond to these agents or experience considerable toxicity. This article reviews the benefits and limitations of currently approved anti-VEGF agents in advanced and metastatic RCC, and the role for newly approved and developmental agents. Sunitinib and bevacizumab plus interferon (IFN)-α have demonstrated significant improvements in progression-free survival (PFS) compared with IFNα in treatment-naïve patients. A PFS benefit has also been shown with sorafenib versus placebo second-line to cytokine therapy. However, no anti-VEGF agent has shown a significant overall survival benefit. Anti-VEGF therapy is generally well tolerated, but a number of key adverse events, including dermatological, mucosal and constitutional symptoms, may limit treatment compliance and success. Pazopanib is a recently approved, highly selective anti-VEGF agent that shows benefit in PFS over IFNα, with low rates of treatment-related adverse events and, therefore, may be better tolerated than other currently approved agents. The advent of VEGF-targeted therapy for RCC has greatly improved prospects for patients with advanced or metastatic disease, but more efficacious agents are required that demonstrate a clear survival advantage. Ongoing trials evaluating novel anti-VEGF therapies could establish whether the increased potency and selectivity of these agents results in improved efficacy and tolerability in RCC patients, further improving their prognosis.

Angiogenesis in renal cell carcinoma: correlation of microvessel density and microvessel area with other prognostic factors

This study was aimed at evaluating the association between tumor vascularity and other known prognostic factors in different histopathological subtypes of renal cell carcinoma (RCC). In 41 cases of RCC, immunohistochemistry was performed using anti-CD34 antibody and Ki-67 (MIB-1). Microvessel density was estimated in an area of 0.23 mm(2) representative of the highest microvessel density ("hot spot"). The microvessel area (MVA) was expressed as percentage of total tumor area occupied by vessels. Endothelial proliferation index (EPI) was determined from sections stained by Ki-67. The relationship between MVD, MVA, EPI and prognostic parameters of RCC like stage, grade and tumor cells proliferation index (TPI) was evaluated. The tumor MVA increased significantly with the higher stage of the tumor (P < 0.001) and increase in TPI (P < 0.05). The MVD, however, did not show significant correlation with grade and stage of the tumor. Microvessel area appears to be a better prognostic marker for RCC when compared to microvessel density. The increase in MVA, without increase in MVD, with increasing stage may be due to the development of larger diameter vascular channels in higher-stage tumors, and this is thought to facilitate metastasis.

Clinical factors associated with outcome in patients with metastatic clear-cell renal cell carcinoma treated with vascular endothelial growth factor-targeted therapy

BACKGROUND

Therapy targeted against the vascular endothelial growth factor (VEGF) pathway is a standard of care for patients with metastatic renal cell carcinoma (RCC). The identification of patients who are more likely to benefit from these agents is warranted.

METHODS

In total, 120 patients with metastatic clear-cell RCC received bevacizumab, sorafenib, sunitinib, or axitinib on 1 of 9 prospective clinical trials at the Cleveland Clinic. Clinical features associated with outcome were identified by univariate analysis; then, a stepwise modeling approach based on Cox proportional hazards regression was used to identify independent prognostic factors and to form a model for progression-free survival (PFS). A bootstrap algorithm was used to provide internal validation.

RESULTS

The overall median PFS was 13.8 months, and the objective response according to the Response Criteria in Solid Tumors was 34%. Multivariate analysis identified time from diagnosis to current treatment <2 years; baseline platelet and neutrophil counts >300 K/microL and >4.5 K/microL, respectively; baseline corrected serum calcium <8.5 mg/dL or >10 mg/dL; and initial Eastern Cooperative Oncology Group performance status >0 as independent, adverse prognostic factors (PF) for PFS. Three prognostic subgroups were formed based on the number of adverse prognostic factors present. The median PFS in patients with 0 or 1 adverse prognostic factor was 20.1 months compared with 13 months in patients with 2 adverse prognostic factors and 3.9 months in patients with >2 adverse prognostic factors.

CONCLUSIONS

Five independent prognostic factors for predicting PFS were identified and were used to categorize patients with metastatic RCC who received VEGF-targeted therapies into 3 risk groups. These prognostic factors can be incorporated into patient care and clinical trials that use such novel, VEGF-targeted agents.

Renal cell carcinoma presenting with skull metastasis: a case report and literature review

The occurrence of metastasis to the head and neck region in renal cell carcinoma is extremely rare. An 80-year-old man presented with a soft nodule in the left parietal calvarium and was admitted to our hospital. Biopsy of the nodule showed nests of clear tumor cells, suggesting metastatic renal cell carcinoma. Computed tomography of the abdomen revealed a well-defined hypervascular tumor, measuring around 7 x 7 x 8 cm, exophytic from the lower pole of the right kidney. Since there were no other systemic metastases, right nephrectomy and complete resection of the skull lesion were performed. No adjunctive therapy was given postoperatively. After 22 months of follow-up, the patient was well and without evidence of disease.

Defective Jak-Stat activation in renal cell carcinoma is associated with interferon-alpha resistance

Chemotherapy is ineffective against metastatic renal cell carcinoma (RCC). Interferon (IFN)-alpha has become the most common agent used in clinical therapy to overcome this malignant tumor, although a satisfactory response has not been achieved and the mechanism of resistance of RCC to IFN-alpha remains unclear. The purpose of the present study was to evaluate the susceptibility of RCC cells to IFN-alpha and clarify the mechanism of IFN-alpha resistance in RCC. Six RCC cell lines and three types of IFN-alpha were used, and the expression, activation and effects of transfection of possible proteins or factors reported to be involved in IFN-alpha signaling were examined to clarify the mechanism of resistance. The results suggest that the resistance of RCC to IFN-alpha is associated with the lack of Jak1, Tyk2 and Stat1 expression and defective Jak-Stat activation, but not with a lack of IFN-alpha receptor, suppressors of cytokine signaling induction or other factors examined. Moreover, phosphorylation of Jak-Stat pathway components and reversion of IFN-alpha resistance in RCC were observed upon transfection with Jak1, Tyk2 or Stat1 vector. These results suggest that restoring the expression of Jak or Stat1 might strikingly increase the susceptibility of RCC to IFN-alpha and may be a new strategy for improving the response of RCC to IFN-alpha treatment. The Jak-Stat pathway should therefore be an appropriate target for the treatment of RCC.

Demethylating Agent 5-Aza-2′-Deoxycytidine Enhances Susceptibility of Renal Cell Carcinoma to Paclitaxel

OBJECTIVES

To examine the effect of 5-aza-2'-deoxycytidine (DAC), a DNA methyltransferase inhibitor, on the growth of renal cell carcinoma (RCC) and examine the synergistic growth suppression by DAC and chemotherapeutic agents.

METHODS

The synergy of DAC and chemotherapeutic agents against RCC cell lines was analyzed by isobolographic analysis. The induction of apoptosis and cell cycle arrest by each single agent or the combination of agents was examined by flow cytometric analysis. Caspase activity assays and proliferating cell nuclear antigen protein expression were also examined to clarify the mechanism of the synergism of DAC and chemotherapeutic agents against RCC.

RESULTS

We demonstrated that DAC combined with paclitaxel (PTX) synergistically inhibited the growth of all the RCC cell lines tested, but DAC did not show such synergism with 5-fluorouracil, vinblastine, or Adriamycin. DAC suppressed RCC cell proliferation by inducing G2/M cell cycle arrest without inducing apoptosis, and PTX induced both apoptosis and G2/M cell cycle arrest in a dosage-dependent manner. DAC could enhance the PTX-induced upregulation of caspase activity and antiproliferative effect to increase the fraction of cells in the sub-G1 and G2/M phase.

CONCLUSIONS

DAC and PTX caused synergistic growth suppression of RCC, suggesting that DAC could strikingly increase the susceptibility of RCC to PTX and that combination chemotherapy with DAC and PTX might be a novel strategy to improve the clinical response rate of RCC.

Validation and Extension of the Memorial Sloan-Kettering Prognostic Factors Model for Survival in Patients With Previously Untreated Metastatic Renal Cell Carcinoma

Purpose

To validate the Motzer et al prognostic factors model for survival in patients with previously untreated metastatic renal cell carcinoma (RCC) and to identify additional independent prognostic factors.

Patients and Methods

Data were collected on 353 previously untreated metastatic RCC patients enrolled onto clinical trials between 1987 and 2002.

Results

Four of the five prognostic factors identified by Motzer were independent predictors of survival. In addition, prior radiotherapy and presence of hepatic, lung, and retroperitoneal nodal metastases were found to be independent prognostic factors. Using the number of metastatic sites as surrogate for individual sites (none or one v two or three sites), Motzer’s definitions of risk groups were expanded to accommodate these two additional prognostic factors. Using this expanded criteria, favorable risk is defined as zero or one poor prognostic factor, intermediate risk is two poor prognostic factors, and poor risk is more than two poor prognostic factors. According to Motzer’s definitions, 19% of patients were favorable risk, 70% were intermediate risk, and 11% were poor risk; median overall survival times for these groups were 28.6, 14.6, and 4.5 months, respectively (P < .0001). Using the expanded criteria, 37% of patients were favorable risk, 35% were intermediate risk, and 28% were poor risk; median overall survival times of these groups were 26.0, 14.4, and 7.3 months, respectively (P < .0001).

Conclusion

These data validate the model described by Motzer et al. Additional independent prognostic factors identified were prior radiotherapy and sites of metastasis. Incorporation of these additional prognostic factors into the Motzer et al model can help better define favorable risk, intermediate risk, and poor risk patients.

Comparative Analysis of Caspase Activation and Apoptosis in Renal Tubular Epithelial Cells and Renal Cell Carcinomas

BACKGROUND/AIMS

Treatment of renal cell carcinoma (RCC) is limited by its resistance to conventional chemotherapies. This may occur, in part, from resistance to apoptosis. The role of caspase activation in apoptosis resistance in treated RCCs was investigated.

METHODS

Two human RCC cell lines (ACHN and SN12K1) and renal tubular epithelial cells (HK2) were treated with 5-fluorouracil (0.2-20 microg/ml) or cisplatin (1-100 microM). Activation of caspase-3 and -2 was analysed and compared with levels of apoptosis. Caspase function was analysed using pan-caspase inhibition (z-VAD-fmk) and caspase-2 inhibition (z-VDVAD-fmk).

RESULTS

RCC apoptosis was significantly lower (p < 0.05) than in HK2s after treatment, confirming their chemoresistance. Pro-caspase-3 (32 kDa) was detected in all cell lines. Cleaved caspase-3 (19 kDa) was not detected by Western immunoblots in treated RCCs and only minimal activated caspase-3 was detected in treated RCCs using immunohistochemistry. All cells had pro-caspase-2 (48 kDa) and the activated form (33 kDa) appeared in all treated cells. Caspase inhibition caused a reduction in, but not negation of, therapy-induced apoptosis in HK2s and RCCs (p < 0.05 for HK2s and ACHN cells), indicating that a caspase activation pathway must occur in RCC apoptosis but this pathway does not act via caspase-3 cleavage. Inhibition of caspase-2 reduced apoptosis only in HK2s, indicating that the activated caspase-2, identified in treated RCCs, was not responsible for their apoptosis induction.

CONCLUSION

Specific differences in caspase-3 and -2 activation were identified in renal tubular epithelium and RCCs after chemotherapy. Identification of RCC-specific caspase inactivation or redundancy may explain, in part, the resistance of RCCs to cancer therapies and may be useful in targeting apoptotic pathways to overcome RCC resistance to treatment.

Prognostic Factors in Patients with Advanced Renal Cell Carcinoma

The identification of prognostic factors in patients with metastatic renal cell carcinoma represents an area of increasing interest. Multiple publications identifying pertinent clinical and laboratory variables have appeared since 1986. The current study of 353 patients with advanced disease treated at The Cleveland Clinic from 1987 to 2002 was conducted to additionally assess and validate a model proposed recently by investigators from Memorial Sloan-Kettering Cancer Center. The data presented are similar to those reported previously, which demonstrated that patients with metastatic renal cell carcinoma can be categorized into good-, intermediate-, and poor-risk groups, using readily available clinical factors. Additionally, comparability of patients in this database to a group treated recently in France was assessed. These two groups appear similar in their distribution of various clinical factors and survival. Finally, a group of international investigators has been developed to provide a comprehensive database of >4,000 patients with metastatic renal cell carcinoma to provide and validate a single model that can be used to predict survival. This project is now under way.

Microscopic venous invasion in renal cell carcinoma as a predictor of recurrence after radical surgery

BACKGROUND

The objective of the present study was to investigate the significance of microscopic venous invasion (MVI) as a prognostic factor for patients with renal cell carcinoma (RCC) who underwent radical surgery.

METHODS

The study included a total of 157 consecutive patients with non-metastatic RCC who underwent radical surgery between January 1986 and December 2002. The median follow-up period was 45 months (range 6-162 months). Microscopic venous invasion was defined by the presence of a cancer cell in blood vessels based on the examination of hematoxylin-eosin stained specimens. Other prognostic variables were assessed by multivariate analysis to determine whether there was a significant impact on cancer-specific and recurrence-free survivals.

RESULTS

Microscopic venous invasion was found in 70 patients, and of this number, 17 (24.7%) developed a tumor recurrence and 12 (17.1%) died of cancer progression, while only six (6.9%) of the remaining 87 patients without MVI presented with disease-recurrence and three (3.5%) died of cancer. Among the factors examined, the presence of MVI was significantly associated with age, mode of detection, tumor size, pathological stage and tumor grade; however, only pathological stage was an independent predictor for disease-recurrence, and none of these factors were available to predict cancer-specific survival in multivariate analyses. In 120 patients with pT1 or pT2 disease, MVI was noted in 36 patients. In this subgroup, recurrence-free survival rates in patients with MVI were significantly lower than those in patients without MVI, and MVI was the only independent prognostic predictor for disease-recurrence in a multivariate analysis.

CONCLUSION

Microscopic venous invasion is not an independent prognostic factor in patients with non-metastatic RCC who underwent radical surgery; however, it could be the only independent predictor of disease-recurrence after radical surgery for patients with pT1 or pT2 disease.

Analysis of the prognostic implications of different tumour margin types in renal cell carcinoma

AIMS

Invasion of perinephric tissues is part of the Union Internationale Contre le Cancer (UICC) (1997) T staging criteria for renal cell carcinoma (RCC) and appears to confer a worse prognosis. However, there are no established histological criteria to determine if this has occurred and histopathologists differ in their interpretation of the tumour margin. The purpose of this study was to determine histological criteria for invasion of perinephric tissues that may be used in staging.

METHODS AND RESULTS

We assessed the prognostic implications of different margin types in 176 cases of RCC with good follow-up data. The tumour margin type in each cases was classified as follows: fibrous tumour capsule; rim of kidney; fibrous capsule with 'collar stud' invasion; pushing margin, no capsule; and tumour cell invasion of fat. The margin types were used in univariate and multivariate survival analysis to determine which had most impact on disease-free survival. In Cox regression analysis with all other influential covariates cellular invasion of fat was the only margin type that had any prognostic impact, conferring a 2.9 relative hazard compared with tumours with a fibrous capsule (P = 0.007).

CONCLUSIONS

For staging purposes the designation of a tumour as invading perinephric tissues should be limited to those cases that have tumour cells invading the perinephric fat.

Prognostic factors of renal cell carcinoma

PURPOSE

Determination of prognostic factors is essential for the management of renal cell carcinoma. Stage, histological grade and type, and performance status are now well known and commonly used. During the last decade numerous predictors of patient outcome were tested. This review summarizes the most important studies, explores and compares the results, and tries to respond to the question, "Today, what do we expect of clinical, molecular and genetic factors concerning survival of patients with renal cell carcinoma?"

MATERIALS AND METHODS

Based on MEDLINE literature searches we comprehensively reviewed the literature on the prognostic factors associated with the tumor, the patient and the treatment.

RESULTS

During the last decades numerous factors have been studied but few of them maintained independent significance in terms of overall survival as assessed by multivariate analysis. Results are more often controversial from one series to another. No known molecular or cytogenetic tumor marker has been identified to help diagnose, manage or confirm renal cell carcinoma remission, progression or relapse.

CONCLUSIONS

The classical prognostic factors remain histological grade, histological type, performance status, patient age, number and location(s) of metastatic sites, time to appearance of metastases and prior nephrectomy. The only striking advancement during the last few years has been the proven contribution of radical nephrectomy for metastatic disease in patients with good performance status.

Contribution of grade, vascular invasion and age to outcome in clinically localized renal cell carcinoma

OBJECTIVE

To determine the relative prognostic importance of microvascular invasion in apparently localized renal cell carcinoma (RCC).

PATIENTS AND METHODS

A retrospective clinical and pathological review was conducted of 176 consecutive patients identified from pathology records who had a nephrectomy for RCC with a median follow-up of 44 months. Vascular invasion was recorded and categorized by the level of microvascular invasion (MVI), renal vein invasion (RVI) and inferior vena cava invasion (IVCI). Tumour type, grade and size were also assessed. These variables were assessed by univariate and multivariate analysis to determine their effect on disease-free survival.

RESULTS

In the univariate analysis tumour size, grade, vascular invasion and young age each predicted reduced disease-free survival. On multivariate analysis for all 176 patients, grade, vascular invasion and young age were the significant independent predictors of reduced disease-free survival. In a subgroup of 149 patients from whom those with very high risk determinants were excluded (those with grade 4 tumours and/or IVCI) most of the risk of metastasis could be accounted for by vascular invasion and young age alone (MVI vs no vascular invasion, hazard ratio 3.18, 95% confidence interval 1.29-7.84; RVI vs no vascular invasion 2.41, 0.989-5.89; and age per year 0.963, 0.94-0.992).

CONCLUSIONS

Grade, vascular invasion and young age are the main independent predictors of relapse in clinically localized RCC after nephrectomy. For most patients, who do not have very high risk indicators, the main adverse predictors are vascular invasion and young age. These findings are important when selecting patients for trials of adjuvant therapy and have implications for pathological staging.

Introducing the clusterin gene into human renal cell carcinoma cells enhances their metastatic potential

PURPOSE

We recently reported a protective role of clusterin expression against apoptosis induced by a wide variety of stimuli in several human cancer models. In the current study we tested the hypothesis that clusterin over expression confers a benefit for the metastasis of renal cell carcinoma through the inhibition of apoptosis induced by the various obstacles the cancer cells may confront after detachment from their primary origin.

MATERIALS AND METHODS

We introduced clusterin complementary DNA into human renal cell carcinoma ACHN cells, which do not express detectable level of clusterin expression, and generated the clusterin over expressing cell line ACHN/CL and the control vector only transfected cell line ACHN/C. In vitro anti-cell death activity under anchorage independent conditions among ACHN sublines was examined by limiting dilution assay and cell survival assay in suspension. To investigate the in vivo effects of clusterin over expression on metastatic potentials each cell line was injected into the tail vein or renal subcapsule of nonobese diabetic, severe combined immunodeficient mice and the metastatic features in all abdominal and thoracic organs were evaluated.

RESULTS

ACHN/CL showed significantly enhanced growth in limiting dilution cultures compared with ACHN/C. The analysis of cell survival in the floating assay also revealed that ACHN/CL had a powerful survival advantage in suspension compared with ACHN/C. Furthermore, ACHN/CL formed more than 5-fold as many metastatic nodules in the lung after intravenous injection than ACHN/C. Similarly more marked lung metastasis was observed after implanting ACHN/CL cells into the renal subcapsule than after implanting ACHN/C cells. In contrast, there were no significant differences among ACHN sublines in the growth rates in vitro and in vivo, cell motility or invasive ability.

CONCLUSIONS

These findings suggest that, if clusterin is over expressed, it prolongs cell survival under unfavorable conditions in the metastatic process, resulting in the enhanced metastatic potential of renal cell carcinoma.

Over expression of clusterin is an independent prognostic factor for nonpapillary renal cell carcinoma

PURPOSE

Recent studies have revealed the powerful anti-apoptotic activity of clusterin in several types of malignant tumors. However, the significance of clusterin expression in human renal cell carcinoma has not been well characterized. We determined whether the expression level of clusterin in nonpapillary renal cell carcinoma may be used as predictor of tumor progression and prognosis.

MATERIALS AND METHODS

Total RNA was extracted from 93 nonpapillary renal cell carcinomas obtained at surgery and expression levels of clusterin messenger (m)RNA in these specimens were measured by Northern blot analysis. Findings were analyzed with respect to several clinicopathological factors.

RESULTS

There were 48 cases (52%) with strong clusterin mRNA expression and 45 (48%) in which it was weak or nonexistent. The expression level of clusterin mRNA did not significantly correlate with patient gender, age, tumor grade or size, or histological cell type, whereas pathological stage and the incidence of tumor recurrence were closely associated with clusterin expression (p <0.005 and <0.01, respectively). The recurrence-free and overall survival rates in patients with strong clusterin expression were significantly lower than in those with weak or no expression (p <0.05). Furthermore, multivariate analyses revealed that strong expression of clusterin was an independent predictor of tumor recurrence and overall survival (p <0.05).

CONCLUSIONS

These findings suggest that the over expression of clusterin may be a useful prognostic parameter in patients with nonpapillary renal cell carcinoma after radical nephrectomy.

Chromosome 9 and 17 aberrations and p53 gene deletion detected by fluorescence in situ hybridization in renal-cell carcinoma

BACKGROUND AND PURPOSE

Nuclear grade and tumor stage have been reported as important prognostic factors for renal-cell carcinoma (RCC), but tumors of similar stage and grade can still exhibit wide variations in biologic behavior and clinical outcome. Fluorescence in situ hybridization (FISH) has recently been applied to RCC. This study was designed to investigate whether aberrations of some chromosomes or genes detected by FISH are related to the progression of RCC.

MATERIALS AND METHODS

We examined 52 patients with RCC, including 31 patients without metastasis (control group) and 21 patients with either concurrent or subsequent metastasis (metastatic group). Paraffin-embedded specimens of the primary tumors were analyzed by FISH for aberrations of chromosomes 9 and 17, as well as for p53 gene alterations.

RESULTS

The incidence of aberrations of chromosome 9 was higher in the metastatic group than in the control group. The p53 gene deletion rate was significantly higher in the metastatic group than in the control group. When the metastatic group was separated into concurrent and subsequent metastasis subgroups, chromosome 17 aberrations as well as p53 gene deletion were significantly more common in the subsequent metastasis group than in the control group.

CONCLUSIONS

Numerical aberrations of chromosome 17 as well as p53 gene deletion detected by FISH may be markers of chromosomal instability in RCC and are probably associated with an increased propensity to metastasize.

Introduction of clusterin gene into human renal cell carcinoma cells enhances their resistance to cytotoxic chemotherapy through inhibition of apoptosis both in vitro and in vivo

Recent studies have revealed the powerful antiapoptotic activity of clusterin in various malignant tumors; however, the significance of clusterin expression in the acquisition of a resistant phenotype against several kinds of treatment in human renal cell carcinoma (RCC) has not been well characterized. We, therefore, transfected the clusterin cDNA into RCC ACHN cells, that scarcely express clusterin protein, to examine whether overexpression of clusterin inhibits chemotherapy-induced apoptosis both in vitro and in vivo. Although no significant differences were observed in the in vitro growth rates between clusterin-transfected ACHN (ACHN/CL) and the vector only-transfected cell line (ACHN/Co), ACHN/CL exhibited high resistance to cisplatin treatment compared with ACHN/Co, with a greater than 5-fold higher IC(50) through the inhibition of apoptotic cell death, which was demonstrated by DNA fragmentation analysis and western blotting of PARP protein. Moreover, intravenous administration of cisplatin into athymic nude mice bearing ACHN/CL tumors resulted in 2- to 3-times faster tumor growth compared with ACHN/Co tumors. These findings suggest that clusterin overexpression helps confer a chemoresistant phenotype through inhibition of apoptosis in human RCC cells.

Significance of serum amyloid A on the prognosis in patients with renal cell carcinoma

BACKGROUND

Evidence of systemic inflammation, i.e., elevation of serum C-reactive protein, interleukin-6, and/or the erythrocyte sedimentation rate, is correlated to poorer prognosis of patients with renal cell carcinoma (RCC). Serum amyloid A (SAA) has been recognized mainly as acute-phase reactant.

METHODS

Serum SAA from 72 patients with RCC were examined. Thirty-eight of 72 patients with RCC had elevated SAA compared with 17 healthy donors.

RESULTS

The disease specific survival rate was significantly lower in the elevated SAA group, and SAA level was shown to be an independent prognostic factor by univariate and multivariate analysis.

CONCLUSIONS

Evaluation of serum SM level in RCC patients may be a useful prognostic indicator.

Cyst-associated renal cell carcinoma: clinicopathologic characteristics and evaluation of prognosis in 27 cases

BACKGROUND

No consistent clinicopathologic characteristics of cyst-associated renal cell carcinoma (CRCC) have previously been determined.

METHODS

In total, 768 patients with renal cell carcinoma (RCC) underwent radical or partial nephrectomy. Renal cell carcinoma was classified as CRCC in 27 of these patients (3.5%, subdivided into RCC originating in a cyst and cystic RCC), clear-cell RCC in 662 patients (86.2%), chromophobe cell renal carcinoma in 36 patients (4.7%) and papillary RCC in 43 patients (5.6%) according to the criteria of the World Health Organization.

RESULTS

The pathologic stage and nuclear grade were usually lower in those with CRCC (low stage/low grade; 89%/96%) or chromophobe cell renal carcinoma (low stage/low grade; 89%/80%) than in those with clear-cell RCC (low stage/low grade; 59%/65%) or papillary RCC (low stage/low grade; 53%/69%). Of the 27 CRCC patients, only 19 (70%) could be diagnosed through preoperative imaging studies. Patients with CRCC showed a favorable prognosis (survival rate: 95% at 1 year, 89.7% at 3 years and 84.4% thereafter) and, especially among the patients with RCC originating in a cyst, no cancer-related death was observed. Comparing the survival among four types of RCC, a favorable outcome was observed in cases of CRCC or chromophobe cell renal carcinoma compared with clear-cell RCC or papillary RCC (clear vs chromophobe: P = 0.002; chromophobe vs papillary: P = 0.019; clear vs cyst-associated: P = 0.001; papillary vs cyst-associated: P = 0.00079).

CONCLUSIONS

In cases of CRCC, the disease was usually detected at lower stages and grades and therefore the prognosis was better than in cases of other types of RCC. Preoperative diagnosis of this disease was very difficult, especially in cases of RCC originating in a cyst.

Prognostic evaluation of transcatheter arterial embolization for unresectable renal cell carcinoma with distant metastasis

OBJECTIVE

To evaluate the efficacy of transcatheter arterial embolization (TAE) in patients with unresectable renal cell carcinoma (RCC) and distant metastasis at the time of diagnosis.

PATIENTS AND METHODS

The study included 54 patients with histologically defined RCC (by biopsy in 28 and autopsy in 26) who were unable to undergo nephrectomy mainly because their performance status was poor (score > or = 2). The patients were classified into two groups; 24 patients who underwent TAE with ethanol and 30 patients who did not. The two groups were compared for several clinical factors, mainly focusing on the prognosis.

RESULTS

There were no significant differences in the clinical factors, including performance status, tumour diameter, vascular invasion, lymph node involvement, adjuvant therapy, metastatic organs or the number of metastases between the groups. However, the proportion of patients with para-neoplastic signs in those undergoing TAE was greater than that in those not, and the difference was significant (chi squared 0.35, P < 0.05). The median survival of the two groups was 229 days (TAE) and 116 days (no TAE). The 1-, 2- and 3-year survival rates in the TAE group were 29%, 15% and 10%, respectively, and in those not undergoing TAE were 13%, 7% and 3%, respectively. Those undergoing TAE had a significantly better prognosis than those who did not (P = 0.019). The adverse effects in patients undergoing TAE with ethanol included fever, back pain on the affected side, nausea and vomiting, but all the patients recovered from these adverse effects.

CONCLUSION

TAE with ethanol is a safe and effective treatment for patients with unresectable disseminated RCC and a poor performance status; TAE with ethanol not only induces ablation of the primary tumour, but also prolongs survival.

Value of immunohistochemical Ki-67 and p53 determinations as predictive factors of outcome in renal cell carcinoma

OBJECTIVES

Nuclear grade and tumor stage are important prognostic factors in renal cell carcinoma, but tumors of similar stage and grade can exhibit a wide variation in biologic behavior and clinical outcome. In this retrospective study, we evaluated the immunologic markers, Ki-67 (MIB1) and p53, in 73 cases of conventional (clear cell) renal cell carcinoma and compared these markers with the accepted prognostic features of grade, stage, and tumor size in predicting outcome.

METHODS

Specimens of 73 renal cell carcinomas of different nuclear grade (20 Furhman I/II, 32 Fuhrman III, and 21 Fuhrman IV) and different stage (10 pT1, 23 pT2, 36 pT3, and 4 pT4) were immunostained with monoclonal antibodies against Ki-67 and p53.

RESULTS

Univariate statistical analysis showed that tumor size (P <0. 001), nuclear grade (P <0.01), tumor stage (P <0.01), Ki-67 index (P <0.001), and p53 immunostaining (P <0.03) correlated significantly with a poor prognosis. A Ki-67 index of 20% was a powerful predictor of survival in all patients (P <0.00001), with strong predictive values. On multivariate analysis, the Ki-67 index and metastases were significant independent prognostic factors (P <0.02 and <0.01, respectively).

CONCLUSIONS

Ki-67 immunostaining appeared to be an additional prognostic indicator of biologic aggressiveness in renal cell carcinoma. Immunohistochemical assessment of tumor antigens could be used to identify patients at high risk of tumor progression in addition to conventional prognostic factors.

Renal sinus involvement in renal cell carcinomas

The renal sinus is the fatty compartment located within the confines of the kidney not delineated from the renal cortex by a fibrous capsule. Because it contains numerous veins and lymphatics, invasion into this compartment may permit dissemination of a tumor otherwise regarded as renal-limited. Thirty-one consecutive renal carcinomas were studied: 22 clear cell renal cell carcinomas (3 multilocular cystic renal cell carcinomas), 4 chromophobe renal carcinomas, and 5 papillary renal carcinomas. The entire interface between the neoplasm and the sinus was embedded. Seventeen carcinomas did not invade the renal sinus and 16 were pT1 or pT2 tumors. Fourteen carcinomas, 13 clear cell renal cell carcinoma and one chromophobe renal carcinoma, invaded the renal sinus fat, and 9 of 14 invaded the lumen of renal sinus veins (all clear cell renal carcinomas). Although 14 of 22 clear cell renal carcinomas appeared to be renal limited pT1 and pT2 cancers, 6 of 14 carcinomas invaded sinus fat and 4 invaded into the lumen of renal sinus veins. Compared with the nine sinus-negative clear cell renal cell carcinomas, the 13 sinus-positive cancers were larger, exhibited more frequent renal capsule and renal vein involvement, and had higher nuclear grades. Renal sinus invasion was most common in clear cell renal cell carcinomas but was uncommon (one in 12) in 3 more indolent renal cell carcinomas: multilocular cystic renal cell carcinoma, chromophobe renal carcinoma, and papillary renal carcinoma. The follow-up period was short (1-17 months), but metastases developed in four of 31 cases. In three cases with metastases, carcinoma had involved the lumen of sinus veins but not the main renal vein, although two of three had also invaded through the renal capsule. This study shows that in carcinomas which appear to be renal limited (pT1/pT2), seven of 23 (30.4%) had invaded sinus fat and four of 23 (17.4%) had invaded sinus veins. We conclude that renal sinus invasion, especially sinus vein invasion, could identify a patient at risk for metastases even in a putative renal limited tumor, and suggest that all cases be examined for this feature. Renal sinus invasion merits further investigation to establish its prognostic importance and possible incorporation into future revisions of the TNM staging system for renal cell carcinomas.

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.

Significance of serum-soluble CD95 (Fas/APO-1) on prognosis in renal cell cancer patients

Serum-soluble CD95 (sCD95) levels for 72 renal cell cancer patients were significantly higher than those of 17 healthy donors. Twenty-one of 72 patients had elevated (defined as more than mean of healthy donors + 2 s.d.) sCD95. The disease-specific survival rate was significantly lower in the elevated sCD95 group. Serum sCD95 level was shown to be an independent prognostic factor by univariate and multivariate analysis, indicating a possible significant role in determining treatment strategies.

Paradoxical spread of renal cell carcinoma to the head and neck

OBJECTIVES

To present cases of renal cell carcinoma presenting with only head and neck metastases, to review theories of physiology and anatomy describing this phenomenon, and to discuss the role of the otolaryngologist in the treatment of these lesions.

STUDY DESIGN

Retrospective review of the records of three patients who presented with renal cell carcinoma with head and neck metastases over the 3-year period from 1992 to 1995.

METHODS

Retrospective review of the records of three patients who presented with renal cell carcinoma with head and neck metastases. In addition, English-language literature was reviewed with special focus on the anatomic and physiologic pathways possible to allow for such a phenomenon.

CONCLUSIONS

Renal cell carcinoma has an occasional presentation as a head and neck mass without evidence of disease elsewhere. Various routes of spread have been postulated. Batson's venous plexus, as postulated by Nahum and Bailey, is an anatomic route through which emboli could navigate to the head and neck and avoid pulmonary vascular filtration. Interactions on the cellular level may also be responsible for the seemingly paradoxical spread. We recommend local excision of head and neck metastases of renal cell carcinoma without sacrifice of vital structures as a sound treatment regimen.

Cystic renal cell carcinoma: pathological features, survival and implications for treatment

OBJECTIVES

To assess the incidence, clinicopathological features, prognosis and therapeutic options of cystic renal cell carcinoma (CRCC).

PATIENTS AND METHODS

The clinical records and nephrectomy specimens from 206 patients with renal cell carcinoma (RCC) were reviewed after a minimum follow-up of 5 years. The mode of presentation, tumour size, growth pattern, nuclear grade, cytoplasmic appearance and pathological stage at presentation were compared with the outcome, as measured by disease-free and overall survival of the patients.

RESULTS

From the 206 patients with RCC, 25 (12%) were classified as having CRCC; most of these cases (96%) occurred in male patients, as opposed to 64% in the remaining patients RCC (P = 0.0029). The clinical features at diagnosis were similar in both groups, although asthenia, anorexia and weight loss were uncommon in patients with CRCC (P = 0.045). Nuclear grade and pathological stage were usually lower in those with CRCC than in those with RCC (P = 0.0071 and P = 0.0033, respectively). Survival was significantly longer in patients with CRCC (P = 0.0342).

CONCLUSIONS

CRCC is a type of RCC that is usually identified at earlier stages, has a slower growth rate, and is therefore associated with a better prognosis and longer survival than conventional RCC. The differential diagnosis between CRCC, cystic multilocular nephroma and cysts with a superimposed infectious or haemorrhagic process can be extremely difficult in imaging studies, and even in intra-operative frozen-section analysis. Because of this, and with the better prognosis of CRCC, a conservative surgical approach would be the treatment of choice whenever technically feasible.

Comparison of chromosomal aberrations detected by fluorescence in situ hybridization with clinical parameters, DNA ploidy and Ki 67 expression in renal cell carcinoma

To evaluate the significance of chromosomal aberrations in renal cell carcinoma, fluorescence in situ hybridization (FISH) was used to determine its prevalence and correlation with clinical parameters of malignancy. In addition, correlation of chromosomal aberration with Ki 67 expression was analysed. We performed FISH with chromosome-specific DNA probes, and the signal number of pericentromeric sequences on chromosomes 3, 7, 9 and 17 was detected within interphase nuclei in touch preparations from tumour specimen. The incidence of loss of chromosome 3 was significantly higher than those of chromosomes 7, 9 and 17 (P < 0.001, P = 0.03 and P < 0.001 respectively). Hyperdiploid aberration of chromosomes 3 and 17 was significantly correlated with tumour stage (P = 0.03, P = 0.02 respectively), whereas hyperdiploid aberration of chromosome 9 was associated with nuclear grade (P = 0.04). Disomy of chromosome 7 was correlated with venous involvement (P = 0.04). Ki 67 expression was significantly associated with hyperdiploid aberration of chromosome 17 (P = 0.01), but not with aberration of chromosome 3. There was a significant relationship between hyperdiploid aberration of chromosome 7 and Ki 67 expression (P = 0.01). In conclusions, gain of chromosome 17 may reflect tumour development, and aberration of chromosome 7 may affect metastatic potential of malignancy, whereas loss of chromosome 3 may be associated with early stage of tumour development in renal cell carcinoma.

Transcript levels of aquaporin 1 and carbonic anhydrase IV as predictive indicators for prognosis of renal cell carcinoma patients after nephrectomy

Since failure of differentiation has been suggested to be involved in the neoplastic process and progression of tumors, we evaluated whether the transcript levels of differentiation markers of proximal renal tubular cells, from which renal cell carcinoma (RCC) arises, could be used as prognostic markers. We used Northern blot analysis to study the expression of aquaporin 1 (aqp1) and carbonic anhydrase IV (ca4) genes in 66 paired samples of primary RCC and non-tumorous kidney tissues. Poor differentiation of tumor cells and non-clear cell-subtype RCC were significantly associated with low levels of aqp1 transcripts. When patients were divided into 2 groups according to level of aqpI transcript in RCC, a low level of aqp1 was significantly associated with unfavorable outcome. Among 18 patients with metastatic RCC and 40 patients with moderately differentiated RCC, those with RCC expressing low levels of aqpl mRNA demonstrated poorer survival than those with RCC expressing relatively high levels of aqp1. Similarly, decreased expression of ca4 mRNA in RCC was associated with poor survival. On multivariate analysis, transcript levels of aqpI and stage of the tumor were the independent factors predicting disease-specific survival. Transcript levels of aqp1 may serve as a new molecular prognostic marker in patients with RCC following nephrectomy.

Microscopic vascular invasion is the most relevant prognosticator after radical nephrectomy for clinically nonmetastatic renal cell carcinoma

PURPOSE

Although many factors have been considered to predict the outcome after radical nephrectomy, renal cell carcinoma continues to behave unpredictably. In a retrospective study the correlation between microvascular tumor invasion and disease-free survival after surgery for renal cell carcinoma was analyzed.

MATERIALS AND METHODS

Between 1980 and 1993, 180 patients (mean age 60 years) were followed for a mean of 52 months after radical or partial nephrectomy for clinically localized renal cell carcinoma. The relevance of microscopic vascular invasion was compared to classical tumor staging, grade and tumor diameter.

RESULTS

Microscopic vascular invasion was found in 51 patients (28.3%), including 20 (39.2%) with progression (mean interval to progression 72 months). Of 129 patients with no pathological evidence of microscopic vascular invasion only 8 (6.2%) showed progression at a mean interval of more than 160 months. The difference in disease-free survival as a function of microvascular invasion was statistically highly significant (log rank p < 0.00001) and on multivariate analysis this parameter was by far the most relevant predictor of progression.

CONCLUSIONS

In patients who underwent radical nephrectomy for clinically nonmetastatic renal cell carcinoma with microvascular invasion but without lymph node involvement or macroscopic vascular invasion the chance of disease progression is estimated at 45% within 1 year. Microvascular invasion is the single most relevant prognosticator after presumed curative radical nephrectomy for renal cell carcinoma.

Renal neoplasm: The prognostic significance of nodal involvement

– Histologically-proven positive nodal involvement has a markedly negative affect on the prognosis of patients subjected to surgery for renal neoplasm. The incidence of nodal metastases reported in literature is wide-ranging and depends on various factors. A critical retrospective evaluation of literature in terms of survival curves and prognostic factor analysis highlights a particularly heterogeneous picture, due to much methodological bias and frequent violation of assumptions of the statistical analyses used. All these factors prevent a precise, independent prognostic value from being assigned to nodal involvement. The results of the single randomised prospective study (protocom EORTC 30881) on the therapeutic effectiveness of lymphadenectomy have been weakened by the low reported incidence of nodal involvement (about 5%). One of the most plausible explanations for this is the change in the natural history of renal tumours, which are currently diagnosed at low volume and stage, with a consequently low rate of nodal and/or distant metastases. This change in the natural history of the disease has increased the frequency of non-elective nephron-sparing surgery with optional nodal dissection over the last few years. This new approach has weakened the traditionally recognised role of lymphadenectomy in staging the disease.