Prognostic factors of renal cell carcinoma

A three miRNAs panel in paraffin tissue serves as tool for predicting prognosis of renal cell carcinoma

Background

Renal cell carcinoma (RCC) stands as the most prevalent form of urogenital cancer. However, there is currently no universally accepted method for predicting the prognosis of RCC. MiRNA holds great potential as a prognostic biomarker for RCC.

Methods

A total of 100 cases with complete paraffin specimens and over 5-year follow-up data meeting the requirements were collected. Utilizing the clinical information and follow-up data of the specimens, an information model was developed. The expression levels of eight microRNAs were identified using RT-qPCR. Finally, determine and analyze the clinical application value of these microRNAs as prognostic markers for RCC.

Results

Significant differences were observed in the expression of two types of miRNAs (miR-378a-5p, miR-23a-5p) in RCC tissue, and three types of miRNAs (miR-378a-5p, miR-642a-5p, miR-23a-5p) were found to be linked to the prognosis of RCC. Establish biomarker combinations of miR-378a-5p, miR-642a-5p, and miR-23a-5p to evaluate RCC prognosis.

Conclusion

The combination of three microRNA groups (miR-378a-5p, miR-642a-5p, and miR-23a-5p) identified in paraffin section specimens of RCC in this study holds significant potential as biomarkers for assessing RCC prognosis.

Machine Learning-Based Magnetic Resonance Radiomics Analysis for Predicting Low- and High-Grade Clear Cell Renal Cell Carcinoma

PURPOSE

To explore whether high- and low-grade clear cell renal cell carcinomas (ccRCC) can be distinguished using radiomics features extracted from magnetic resonance imaging.

METHODS

In this retrospective study, 154 patients with pathologically proven clear ccRCC underwent contrast-enhanced 3 T magnetic resonance imaging and were assigned to the development (n = 122) and test (n = 32) cohorts in a temporal-split setup. A total of 834 radiomics features were extracted from whole-tumor volumes using 3 sequences: T2-weighted imaging (T2WI), diffusion-weighted imaging, and contrast-enhanced T1-weighted imaging. A random forest regressor was used to extract important radiomics features that were subsequently used for model development using the random forest algorithm. Tumor size, apparent diffusion coefficient value, and percentage of tumor-to-renal parenchymal signal intensity drop in the tumors were recorded by 2 radiologists for quantitative analysis. The area under the receiver operating characteristic curve (AUC) was generated to predict ccRCC grade.

RESULTS

In the development cohort, the T2WI-based radiomics model demonstrated the highest performance (AUC, 0.82). The T2WI-based radiomics and radiologic feature hybrid model showed AUCs of 0.79 and 0.83, respectively. In the test cohort, the T2WI-based radiomics model achieved an AUC of 0.82. The range of AUCs of the hybrid model of T2WI-based radiomics and radiologic features was 0.73 to 0.80.

CONCLUSION

Magnetic resonance imaging-based classifier models using radiomics features and machine learning showed satisfactory diagnostic performance in distinguishing between high- and low-grade ccRCC, thereby serving as a helpful noninvasive tool for predicting ccRCC grade.

Prognostic factors in renal cell carcinoma: A single‑center study

Renal cell carcinoma (RCC) is a heterogeneous and complex disease with numerous pathophysiologic variants. ~40% of patients succumb due to the progression of the disease, making RCC the most fatal of the common urologic malignancies. Prognostic factors are indicators of the progression of the disease, and the precise determination of these factors is important for evaluating and managing RCC. In the present study, it was aimed to determine and find associations among the histopathological features of RCCs and their impact on survival and metastasis. This is a cross-sectional study of RCC cases who have undergone partial or radical nephrectomy from March 2008 to October 2021 and have been pathologically reviewed at Shorsh General Teaching Hospital in Sulaimani, Iraq. The data in the pathology studies were supplemented by follow-up of the patients to obtain information about survival, recurrence and metastasis. In total, 228 cases of RCC were identified, among whom 60.5% were men and 39.5% were women, with a median age of 51 years. The main tumor types were clear cell RCC (71.1%), papillary RCC (13.6%), and chromophobe RCC (11%). Various measures of aggressiveness, including tumor necrosis, sarcomatoid change, microvascular invasion, and parameters of invasiveness (invasion of the renal sinus and other structures), were significantly correlated with each other, and they were also associated with reduced overall survival and an increased risk of metastasis on univariate analysis. However, on multivariate analysis, only tumor size and grade, and microvascular invasion retained statistical significance and were associated with a lower survival rate. In conclusion, pathological parameters have an impact on prognosis in RCC. The most consistent prognostic factors can be tumor size and grade, and microvascular invasion.

Assessment of apparent diffusion coefficient value as prognostic factor for renal cell carcinoma aggressiveness

Background

Assurance of prognostic elements is important for the management of renal cell carcinoma (RCC). Our goal was to check the relation between apparent diffusion coefficient (ADC) values and parameters predicting prognosis of RCC. Fifty pathologically confirmed RCC underwent diffusion-weighted (DW) MRI. ADC values were calculated using b factor (800 s/mm2). The correlation between ADC values and tumor size, cystic/necrotic feature, growth pattern, unenhanced T1, histological grade, clinical stage, and distant metastasis were analyzed.

Results

The optimal ADC threshold for prognosis of RCC appeared to be 1.4 × 10−3 mm2/s. There was a significant inverse correlation between ADC values and growth pattern (R = − 0, P = 0.05), unenhanced T1(R = − 0.41, P = 0.01), cystic/necrotic feature (R = − 0.4, P = 0.01), histological grade (R = − 0.37, P = 0.02), clinical stage (r = − 0.4, P = 0.01), and distant metastasis (R = − 0.33, P = 0.04), and significant linear correlation with tumor size (R = 0.39, P < 0.02).

Conclusion

The performance of ADC value as a newly proposed prognostic parameter follows with the degree of tumor differentiation and that may recognize extremely aggressive RCC. RCC with low ADC values should be inspected extensively for the risk of high pathological grade, high clinical stage, and distant metastasis.

Renal Cancer Treatment: A Review of the Literature

Renal carcinoma represents about 3% of all adult tumors, with an estimate of 31,900 new cases diagnosed in 2003 in the United States. In the early phase of its natural history, renal cancer is potentially curable by surgery, but if the disease presents any signs of metastasis, the chances of survival are remote, even though anecdotal cases characterized by long survival have been reported. In fact, the treatment of metastatic renal cancer remains unsatisfactory. Systemic treatment with single agents and with polychemotherapy, with or without cytokine-based immunotherapy, has not been successful, obtaining very low response rates without a significant benefit in overall survival. This review highlights the most interesting issues regarding conventional therapeutic strategies, in localized and in advanced disease. New approaches such as monoclonal antibodies, vaccines, gene therapy, angiogenesis inhibitors and allogeneic cell transplantation and their possible clinical applications are also discussed.

A new classification of inferior vena cava thrombus in renal cell carcinoma could define the need for cardiopulmonary or venovenous bypass

INTRODUCTION

Although the level of inferior vena cava (IVC) thrombus governs the type of surgical approach, there is no consistency in reporting the levels of IVC thrombus in the literature. This prospective study illustrates a simple three-level classification based on the need for clamping hepatoduodenal ligament and venovenous or cardiopulmonary bypass.

MATERIALS AND METHODS

Between January 2010 and June 2014, 30 patients of renal mass with renal vein and/or IVC thrombus were treated after classifying the IVC thrombus into three levels on the basis of need for clamping the hepatoduodenal ligament. After excluding renal vein thrombi, level I was described as thrombus located caudal to the hepatic vein. Level II included all retrohepatic, suprahepatic infradiaphragmatic or supradiaphragmatic thrombi reaching till the right atrium. Atrial thrombi were categorized as level III. Level I and II thrombi were managed without venovenous or cardiopulmonary bypass. Level III thrombus required cardiopulmonary bypass.

RESULTS

Of 26 patients with thrombus, 13 had level I thrombus. Of eight cases with level II thrombus, three were retrohepatic, three were suprahepatic infradiaphragmatic and two were supradiaphragmatic. All were removed successfully. Of five patients with level III thrombus, three were operated with cardiopulmonary bypass while the remaining two patients were too sick to be taken up for surgery. The median hepatoduodenal ligament clamp time was 10 min. One patient with level II thrombus had transient liver enzyme elevation.

CONCLUSION

Renal vein thrombus should not be categorized as level I thrombus. Level II thrombus, irrespective of its relation to the diaphragm, could be managed without venovenous or cardiopulmonary bypass.

Expression pattern of autophagy-related markers in non-metastatic clear cell renal cell carcinoma: association with disease recurrence following radical nephrectomy

PURPOSE

To evaluate the expression of multiple molecular markers associated with autophagy, a cellular degradation pathway for the clearance of damaged or superfluous proteins and organelles, in clear cell renal cell carcinoma (CCRCC) in order to identify the prognostic significance of these markers in patients undergoing radical nephrectomy.

METHODS

Expression levels of five markers, including autophagy-related gene 5 (Atg5), Atg9, Beclin 1, microtubule-associated protein light chain 3 (LC3), and UNC-51-like kinase 1 (ULK1), in radical nephrectomy specimens from a total of 100 patients with non-metastatic CCRCC were measured by immunohistochemical staining.

RESULTS

All the five markers were significantly correlated with some pathological factors reflecting an aggressive phenotype, including the pathological T stage, tumor grade, and microvascular invasion. During the follow-up period of this series (median 58.0 months), disease recurrence developed in 41 of the 100 patients, with a 5-year recurrence-free survival (RFS) rate of 61.3%. On univariate analysis, expression levels of Atg5 and Beclin 1, in addition to the pathological T stage, microvascular invasion, and preoperative CRP level, were identified as significant predictors of disease recurrence. Of these factors, the expression of Beclin 1 and preoperative CRP level were independently correlated with RFS on multivariate analysis.

CONCLUSION

These findings suggest that the combined assessment of expression levels of autophagy-associated markers, particularly Beclin 1, in radical nephrectomy specimens with conventional prognostic parameters, would contribute to the precise prediction of postoperative disease recurrence in patients with non-metastatic CCRCC.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

KEY POINTS

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

Galectin-1 and Galectin-3 mRNA expression in renal cell carcinoma

Background

Galectins are known to regulate cell differentiation and growth as well as cell adhesion and apoptosis. Galectins have been discussed as possible prognosticators for survival in renal cell cancer (RCC) and other urological tumors. They might also play an emerging role as possible new marker-proteins for RCC. In this study, we analyzed the expression of galectin-1 and galectin-3 mRNA in order to further investigate their clinical significance in RCC.

Methods

Tissue samples were obtained from 106 patients undergoing surgery for RCC. The expression of galectin-1 and galectin-3 mRNA in normal kidney and corresponding cancer tissue was analyzed using quantitative real time PCR. Differences in expression levels of paired tissue samples were assessed using paired two-sample tests. Associations of relative mRNA expression levels in tumor tissues with clinical findings were analyzed using univariate logistic regression.

Results

The expression of galectin-1 (p < 0.001) and -3 (p < 0.001) mRNA were significantly higher in RCC when compared to the adjacent normal kidney tissue. For clear cell RCC, an association of male gender with higher galectin-1 and galectin-3 mRNA expression (p = 0.054, p = 0.034) was detected. For all RCCs, galectin-1 mRNA expression failed to show a significant association with advanced disease as well as a higher rate of lymph node metastases (p = 0.058, p = 0.059).

Conclusion

The mRNA expression of galectin-1 and galectin-3 is significantly increased in RCC cancer tissue. The higher mRNA expression in tumor tissue of male patients raises the question of a functional connection between galectins and the higher prevalence of RCC in men. Associations with advanced disease might lead to new ways of identifying patients at higher risk of recurrent disease and might even facilitate early metastasectomy with curative intent.

Expression of molecular markers associated with the mammalian target of rapamycin pathway in nonmetastatic renal cell carcinoma: Effect on prognostic outcomes following radical nephrectomy

OBJECTIVES

To evaluate the expression of multiple molecular markers involved in mammalian target of rapamycin (mTOR) signaling pathway in renal cell carcinoma (RCC) to determine the prognostic significance of these markers following radical nephrectomy.

MATERIAL AND METHODS

The expression levels of 5 markers, including PTEN, phosphorylated (p)-Akt, p-mTOR, p-p70 ribosomal S6 kinase, and p-4E-binding protein 1 (4E-BP1), were measured in radical nephrectomy specimens from 137 patients with nonmetastatic RCC by immunohistochemical staining.

RESULTS

During the follow-up period of this series (median, 63.5 mo), disease recurrence occurred in 59 of the 137 patients (43.0%), with a 5-year recurrence-free survival rate of 58.3%. On Univariate analysis, expression levels of p-mTOR and p-4E-BP1, in addition to the C-reactive protein level, pathological stage, and microvascular invasion, were identified as significant predictors for disease recurrence. Of these factors, the expression of p-4E-BP1, C-reactive protein level, and pathological T stage appeared to be independently related to recurrence-free survival on multivariate analysis. Moreover, significant differences were observed in recurrence-free survival according to the positive numbers of these 3 independent factors; that is, disease recurrence developed in 5 of 42 patients with negative results for any risk factor (11.9%), 23 of 50 patients with positive results for a single risk factor (46.0%), and 31 of 45 patients with positive results for 2 or 3 risk factors (68.8%).

CONCLUSIONS

The combined evaluation of the expression levels of potential markers in the mTOR signaling pathway, particularly p-4E-BP1, in RCC specimens with conventional prognostic parameters would contribute to the accurate prediction of disease recurrence following radical nephrectomy for nonmetastatic RCC.

[Usefulness of new schemes to group Fuhrman grades in clinical practice for clear cell renal tumour]

OBJECTIVE

To evaluate if re-grading renal cell carcinoma (CRCC) in two or three-tiered grading schemes versus the traditional Fuhrman classification maintains the same prognostic value.

MATERIAL AND METHODS

A study of a cohort of 383 treated CRCC with radical or partial nephrectomy between 1990-2009 was made. We analyzed the demographic data, evolution and survival of these patients. An uropathologist reassigned the Fuhrman grades blindly to the first classification. In order to study if the prognostic value was maintained with the different classification, three Cox multivariate regression analysis were performed, classifying the variable of grade into four categories: (I-II-III-IV), into three (I+II-III-IV) and into two (I+II-III+IV). The explanatory variables were: age, gender, tumor size, study stage and grade. The response variables were progression-free survival (local-regional recurrence/metastasis) and cancer specific survival time.

RESULTS

The median overall survival was 125 months (95% CI: 92-159). In the three multivariate analyses carried out, the Fuhrman classification showed independent predictive value (p=:0.0001) compared to progression-free survival and cancer specific survival. The predictive power was maintained in the new classifications. In the three categories, the changing from grade I+II to III meant RR: 2.31 (p=0.0001) and from grade III to IV RR: 2.47 (p=0.0001) and in two-tiered classification an RR: 2.8 (p=0.001) was found when changing from I+II to III+IV.

CONCLUSIONS

Our results show that categorizing the Fuhrman grade into three or two-tiered grading schemes provide the same predictive accuracy on progressive free survival and cancer specific survival. Grades III and IV have different outcomes so that the three-tiered classification seems to be more appropriate to described the course of these patients.

Full-Length Enrich c-DNA Libraries-Clear Cell-Renal Cell Carcinoma

Clear cell renal cell carcinoma (ccRCC), the most common subtype of RCC, is characterized by high metastasis potential and strong resistance to traditional therapies, resulting in a poor five-year survival rate of patients. Several therapies targeted to VEGF pathway for advanced RCC have been developed, however, it still needs to discover new therapeutic targets for treating RCC. Genome-wide gene expression analyses have been broadly used to identify unknown molecular mechanisms of cancer progression. Recently, we applied the oligo-capping method to construct the full-length cDNA libraries of ccRCC and adjacent normal kidney, and analyzed the gene expression profiles by high-throughput sequencing. This paper presents a review for recent findings on therapeutic potential of MYC pathway and nicotinamide N-methyltransferase for the treatment of RCC.

Clear cell renal cell carcinoma: multiphasic multidetector CT imaging features help predict genetic karyotypes

PURPOSE

To determine whether imaging characteristics at multiphasic multidetector computed tomography (CT) correlate with common karyotypic abnormalities in patients with clear cell renal cell carcinomas (ccRCCs).

MATERIALS AND METHODS

Institutional review board approval was obtained, and informed consent was waived for this HIPAA-compliant retrospective study. From January 2000 through September 2007, the prenephrectomy multiphasic (corticomedullary, nephrographic, and excretory phases), multidetector helical CT images of 58 histologically proved and karyotyped ccRCCs were reviewed by two readers with experience in abdominal imaging. Imaging features assessed included degree of attenuation, contour, and presence of calcifications and neovascularity. These features were independently correlated with specific karyotypic abnormalities on the resected specimens. Degree of attenuation data were analyzed with logistic regression for significance (P < .05), and morphologic characteristics were analyzed with odds ratios for assessing their diagnostic power.

RESULTS

On unenhanced scans, 7% (two of 28) of ccRCCs with the loss of chromosome 3p were calcified, whereas 37% (11 of 30) of lesions without this anomaly were calcified (odds ratio, 0.13). During the corticomedullary phase, ccRCCs with the loss of chromosome Y enhanced more than those without this anomaly (130.0 vs 102.5 HU, P = .04), and ccRCCs with trisomy 7 enhanced less than those without this anomaly (105.8 vs 139.3 HU, P = .04). During the excretory phase, ccRCCs with trisomy 5 enhanced more than those without this anomaly (115.5 vs 83.4 HU, P = .03).

CONCLUSION

The genetic makeup of ccRCCs affects their imaging features at multidetector CT examinations. Multidetector CT imaging characteristics may help suggest differences at the cytogenetic level among ccRCCs.

Prognostic models for renal cell carcinoma recurrence: external validation in a Japanese population

The aim of the present study was to compare the accuracy of three prognostic models in predicting recurrence-free survival among Japanese patients who underwent nephrectomy for non-metastatic renal cell carcinoma (RCC). Patients originated from two centers: Chiba University Hospital (n = 152) and Chiba Cancer Center (n = 65). The following data were collected: age, sex, clinical presentation, Eastern Cooperative Oncology Group performance status, surgical technique, 1997 tumor-node-metastasis stage, clinical and pathological tumor size, histological subtype, disease recurrence, and progression. Three western models, including Yaycioglu's model, Cindolo's model and Kattan's nomogram, were used to predict recurrence-free survival. Predictive accuracy of these models were validated by using Harrell's concordance-index. Concordance-indexes were 0.795 and 0.745 for Kattan's nomogram, 0.700 and 0.634 for Yaycioglu's model, and 0.700 and 0.634 for Cindolo's model, respectively. Furthermore, the constructed calibration plots of Kattan's nomogram overestimated the predicted probability of recurrence-free survival after 5 years compared with the actual probability. Our findings suggest that despite working better than other predictive tools, Kattan's nomogram needs be used with caution when applied to Japanese patients who have undergone nephrectomy for non-metastatic RCC.

Cytoreductive nephrectomy vs medical therapy as initial treatment: a rational approach to the sequence question in metastatic renal cell carcinoma

BACKGROUND

Renal cell carcinoma (RCC) can be considered as two distinct entities: localized and metastatic disease.

METHODS

We conducted a review of the scientific literature published within the past decade pertaining to cytoreductive nephrectomy for metastatic RCC.

RESULTS

Retrospective data and historical prospective series have demonstrated the survival benefit of debulking nephrectomy in well-selected RCC patients. New medical therapies, including vascular endothelial growth factor and mTOR pathway blocking drugs, are active biological agents, with survival improvement and potential regression of metastatic and primary tumors. Our current therapeutic challenge is the optimal integration of multimodal therapy consisting of systemic therapy and surgery including cytoreductive nephrectomy, debulking, and metastasectomy. Empiric data to guide this decision are limited.

CONCLUSIONS

The decision concerning whether medical or surgical therapy should be the primary treatment approach selected must be made on an individual basis, taking into account patient performance status, clinical parameters, and physician expertise and recommendations, thus making each case a unique therapeutic challenge.

Radical or simple nephrectomy in localized renal cell carcinoma: what is a choice?

INTRODUCTION

Renal cell carcinoma (RCC) accounts for approximately 3% of all adult malignancies. Surgery remains the only effective method of renal tumors treatment. In fact, for advanced RCC, radical nephrectomy (RN) should remain a standard treatment. However, in localized RCC (LRCC) a real increase of survival rates realized by RN compared with simple nephrectomy (SN) or organ-sparing surgery is discussable. The aim of our study was to assess the impact of nephrectomy type on the prognosis of LRCC treatment.

MATERIAL AND METHODS

We analyzed the long-term outcomes of RN (n = 248 pts.) and SN (n = 170 pts.) in 418 pts. with LRCC. There were no significant statistical differences in tumor stages, age stratification or gender between these two groups. To compare the efficacy of RN and SN we determined overall survival (OS) and cancer-specific survival (CSS) rates in both divided groups. The 3-year OS in RN group was 93.1% vs. 91.8% in SN group.

RESULTS

CSS rates after the same period were 96.8% vs. 94.7% respectively. The 5-year OS in RN group was 91.5% vs. 88.8% in SN group. After 5 years of follow-up, CSS in RN group was 94.4% vs. 92.4% in SN group. Type of nephrectomy does not influence on LRCC outcomes. The 3- and 5-year overall survival rates and cancer-specific survival rates in RN and SN group were almost identical.

CONCLUSION

Hence, if radical nephrectomy does not ensure better survival than simple nephrectomy, the expediency of vast surgery in localized RCC is doubtful.

Prognostic impact of the 2009 UICC/AJCC TNM staging system for renal cell carcinoma with venous extension

BACKGROUND

The prognostic significance of venous involvement and tumour thrombus level in renal cell carcinoma (RCC) remains highly controversial. In 2010, the American Joint Committee on Cancer (AJCC) and the Union International Centre le Cancer (UICC) revised the RCC staging system (7th edition) based on tumour thrombus level, differentiating the T stage of tumours limited to renal-vein-only involvement.

OBJECTIVE

We aimed to evaluate the impact of tumour thrombus extension in a multi-institutional cohort of patients.

DESIGN, SETTING, AND PARTICIPANTS

An international consortium of 11 institutions was established to retrospectively review a combined cohort of 1215 patients undergoing radical nephrectomy and tumour thrombectomy for RCC, including 585 patients with inferior vena cava (IVC) involvement or higher.

MEASUREMENTS

Predictive factors of survival, including histology, tumour thrombus level, nodal status, Fuhrman grade, and tumour size, were analysed.

RESULTS AND LIMITATIONS

A total of 1122 patients with complete data were reviewed. The median follow-up for all patients was 24.7 mo, with a median survival of 33.8 mo. The 5-yr survival was 43.2% (renal vein involvement), 37% (IVC below the diaphragm), and 22% with caval involvement above the diaphragm. On multivariate analysis, tumour size (hazard ratio [HR]: 1.64 [range: 1.03-2.59]; p=0.036), Fuhrman grade (HR: 2.26 [range: 1.65-3.1]; p=0.000), nodal metastasis (HR: 1.32 [range: 1.09-1.67]; p=0.005), and tumour thrombus level (HR: 2.10 [range: 1.53-3.0]; p=0.00) correlated independently with survival.

CONCLUSIONS

Based on analysis of the largest known cohort of patients with RCC along with IVC and atrial thrombus involvement, tumour thrombus level is an independent predictor of survival. Our findings support the changes to the latest AJCC/UICC staging system.

Serum IgG against Candida predict survival in patients with metastatic renal cell carcinoma

BACKGROUND AND AIM

In contrast to hematologic malignancies, little is known about the role of fungi in the development and progression of solid tumors. This prompted us to analyze and correlate serum levels of different fungal IgG with survival of patients with metastatic renal cell carcinoma.

PATIENTS AND METHODS

Serum IgG to Candida sp., Saccharomyces cerevisiae and Aspergillus fumigatus were measured in a cross-sectional study in 64 patients with advanced disease. Univariate and multivariate analyses were chosen to study serum IgG as prognostic indicators.

RESULTS

Median follow-up was 29.0 months (range 0.3-122). Median overall survival of patients, which tested negative for Candida IgG, was significantly increased (median not reached, >29 months) compared with Candida IgG positive patients (17.8 months, P = 0.002). Median survival of Saccharomyces IgG negative patients was 33.1 months as opposed to 19.4 months in Saccharomyces IgG positive patients, although this difference was not significant (P = 0.281). No difference in overall survival was found between Aspergillus IgG positive patients (28.0 months) and Aspergillus IgG negative patients (29.1 months) (P = 0.181). Cox backward-stepwise regression confirmed Candida IgG as the strongest predictor of survival in metastatic renal cell carcinoma patients (risk ratio 3.27, P = 0.001, [95% CI 1.86-5.73]).

CONCLUSION

Our findings suggest that IgG antibodies directed against yeast fungi and particularly against Candida but not against mold fungi have prognostic relevance.

[Significance of anemia as an independent prognostic factor in patients with renal cell carcinoma]

BACKGROUND AND OBJECTIVE

The aim of this study was to analyze the significance of anemia as well as other prognostic factors influencing survival in patients with renal cell carcinoma (RCC).

PATIENTS AND METHODS

A retrospective review of data of 316 patients who underwent surgery between 1970 and 2003 was performed. Most important known prognostic factors of RCC were investigated.

RESULTS

Most of patients had T1b-T2, low nuclear grade and single tumours. In 8.2% and 9% of cases, lymph node and metastatic dissemination were detected at the time of diagnosis, respectively. At the beginning, most frequent symptoms were hematuria and pain, with anemia (Hb >10g/dl) in 69 patients. After a median follow-up of 50 months, 24.1% of patients had a recurrence. From these, more than 50% developed recurrence within one year after nephrectomy. Advanced tumours (T3-4) consisted of high nuclear grade (III-IV) tumours, larger size tumours, with necrosis and vascular infiltration in surgical specimen, as well as lymph node and metastatic dissemination. In multivariate analysis, anemia, time to recurrence, type of treatment for recurrence as well as lymph node dissemination were independent factors of cancer specific survival.

CONCLUSION

Anemia seems to be a marker of recurrence and progression in patients with renal cell carcinoma undergoing nephrectomy. From our point of view, anemia could be considered a significantly high mortality rate for renal cancer in these patients.

Prognostic relevance of the histological subtype of renal cell carcinoma

OBJECTIVE

According to several studies, when the histological subtype of renal cell carcinoma is established it is possible to attribute a different life expectancy to each patient. We analyzed the prognostic significance of the histological subtype in renal cell carcinoma.

MATERIALS AND METHODS

The authors retrospectively analyzed the follow-up of 230 patients after radical or conservative renal surgery. The histological characteristics of the different subtypes of tumor were obtained and the disease-free and cancer-specific survival curves for the clear cell, cromophobic, papillary, collecting duct (Bellini) subtypes and those with sarcomatoid differentiation were individualized.

RESULTS

The disease-free and cancer-specific survival rates for clear cell tumors were 76.6% and 68.0% respectively, 71.2% and 82.1% respectively for the cromophobic type, 71.1% and 79.8% respectively for the papillary type, 26.9% and 39.3% respectively for the sarcomatoid type, and 0.0% and 0.0% respectively for the collecting ducts (p < 0.001).

CONCLUSION

The histological subtypes of renal tumors can stratify patients into different prognostic groups only when the sarcomatoid differentiation is present.

Survivin expression in renal cell carcinoma

Deregulated expression of inhibitors of apoptosis may contribute to cancer by aberrantly extending cell viability and facilitating the insurgence of resistance to chemo- and radiotherapy. In this study, we have investigated, by immunohistochemical technique, the expression and potential prognostic significance of survivin in a series of 49 clear cell type renal cell carcinoma (ccRCC). Survivin expression was significantly associated with poorly differentiated, advanced stages and more aggressive ccRCCs (p < 0.05). Patients with low survivin expression had statistically significant better survival rates than patients with high survivin expression (p < 0.05). This may be relevant for follow-up protocols design and/or alternative therapeutic approaches.

Pathological tumour diameter predicts risk of conventional subtype in small renal cortical tumours

OBJECTIVE

To examine whether pathological tumour diameter assists in predicting conventional vs other histological subtypes in renal cortical tumours (RCTs) of <or=4 cm diameter.

PATIENTS AND METHODS

In all, 393 patients from Columbia University's Comprehensive Urologic Oncology Database who underwent radical or partial nephrectomy between 1988 and 2005 and had RCTs of <or=4 cm were analysed. Logistic regression analysis using tumour diameter as a continuous variable was used to determine whether size predicted histological subtype. Odds ratios (ORs) were calculated to estimate the likelihood of having conventional histology based on diameter.

RESULTS

The median patient age at surgery was 64.3 years and median tumour diameter was 3 cm, In all, 256 (65.1%) of the RCTs were conventional subtype and 137 (34.9%) were nonconventional. Logistic regression analysis showed that for every 1 cm increase in diameter up to 4 cm, the RCT was 1.27 times more likely to be conventional (P = 0.020). The ORs showed that a 4-cm RCT was 2.06 times more likely to be conventional than tumours of 0.6-1.5 cm.

CONCLUSION

There was a positive association between RCT diameter and the risk of having conventional renal cell carcinoma (RCC). Given that RCC histological subtype is a prognostic indicator for outcome, these findings may be applied in the selection of treatment options. Further studies investigating tumour size and other variables predictive of tumour histology will help clinicians better predict the RCC subtype.

Serum antibodies against Saccharomyces cerevisiae: a new prognostic indicator in metastatic renal-cell carcinoma

PURPOSE

A recent study reported that a diet rich in bread and refined cereals might have an unfavorable role in the development of renal cell carcinoma (RCC). To test whether an underlying intolerance of bread ingredients is responsible for the unfavorable influence of bread on RCC, we examined patient sera for the presence of food-specific IgG.

EXPERIMENTAL DESIGN

A commercial test was used to detect food-specific IgG directed against a panel of 113 food antigens in sera of 54 patients with metastatic RCC. Kaplan-Meier estimates were used for univariate survival analysis, and differences in survival curves were assessed with the log-rank test. Multivariate survival analysis was done using a Cox regression model.

RESULTS

We found that RCC patients with elevated serum levels of IgG antibodies against S. cerevisiae, commonly known as baker's yeast and yet another bread component, have an unfavorable clinical course. Median survival of patients with high levels of S. cerevisiae IgG was only 17.8 months, whereas median survival of patients with low S. cerevisiae IgG was 43.8 months (P = 0.0022; log-rank). Multivariate survival analysis identified high levels of S. cerevisiae IgG as a strong and independent prognostic risk factor (risk ratio 4.6, P = 0.001; 95% CI 1.61-13.08).

CONCLUSIONS

Our findings indicate that serum levels of IgG against S. cerevisiae may predict survival in patients with metastatic RCC. The data suggest not cereals but baker's yeast being the critical component of bread that may cause immune deviation and impaired immunosurveillance in predisposed RCC patients.

Renal cell carcinoma in a patient with cystinosis and inflammatory bowel disease: a case report

An 18-year-old male patient with a history of cystinosis and inflammatory bowel disease, who was being treated with cysteamine and 6-mercaptopurine, had an incidental finding of a mass in the right kidney on a renal ultrasound to evaluate worsening renal insufficiency. Excisional biopsy demonstrated papillary renal cell carcinoma, Type 2. Renal cell carcinoma is typically a disease of older adults, and it is not known to be associated with cystinosis. This is the first published report of renal cell carcinoma in a patient with cystinosis.

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

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

Microarray-based identification of CUB-domain containing protein 1 as a potential prognostic marker in conventional renal cell carcinoma

PURPOSE

Renal cell carcinoma (RCC) is characterized by a variable and unpredictable clinical course. Thus, accurate prediction of the prognosis is important in clinical settings. We conducted microarray-based study to identify a novel prognostic marker in conventional RCC.

PATIENTS AND METHODS

The present study included the patients surgically treated at Kyoto University Hospital. Gene expression profiling of 39 samples was carried out to select candidate prognostic markers. Quantitative real-time PCR of 65 samples confirmed the microarray experiment results. Finally, we evaluated the significance of potential markers at their protein expression level by immunohistochemically analyzing 230 conventional RCC patients.

RESULTS

Using expression profiling analysis, we identified 14 candidate genes whose expression levels predicted unfavorable disease-specific survival. Next, we examined the expression levels of nine candidate genes by quantitative real-time PCR and selected CUB-domain containing protein 1 (CDCP1) for further immunohistochemical analysis. Positive staining for CDCP1 inversely correlated with disease-specific and recurrence-free survivals. In multivariate analysis including clinical/pathological factors, CDCP1 staining was a significant predictor of disease-specific and recurrence-free survivals.

CONCLUSIONS

We identified CDCP1 as a potential prognostic marker for conventional RCC. Further studies might be required to confirm the prognostic value of CDCP1 and to understand its function in RCC progression.

Diagnostic and prognostic molecular markers in renal cell carcinoma

PURPOSE

We reviewed the contemporary literature on molecular biomarkers in renal cell carcinoma and their prognostic significance.

MATERIALS AND METHODS

Articles published during 1981 to 2007 in English on renal cell carcinoma were surveyed using the MEDLINE/PubMed database. The subject headings included were genetics, biomarkers, prognosis and risk models of renal cell carcinoma. We present a synthesis of currently known renal cell carcinoma biomarkers at various stages of development and their clinical significance, and prognostic nomograms incorporating biomarkers.

RESULTS

The beneficiary role of biomarkers in renal cell carcinoma is challenged by the relatively low prevalence of the disease. Even if a biomarker for renal cell carcinoma had 100% sensitivity and 99.4% specificity, the positive predictive value of the marker in men older than 65 years would be only 10%. Several biomarkers are being investigated in renal cell carcinoma, of which many relate to pathogenic molecular changes that are currently therapeutic targets. Carbonic anhydrase IX is a von Hippel-Lindau mediated enzyme that is expressed in most renal cell carcinoma cases. High (greater than 85%) expression of this marker indicates favorable prognosis and may predict the response to interleukin-2 therapy. B7-H1 expression in renal cell carcinoma cells/lymphocytes may indicate worse survival, possibly through impaired host antitumor immunity. Prognostic nomograms incorporating clinical variables and molecular markers to refine the prediction of treatment outcomes are in active development and await prospective clinical validation.

CONCLUSIONS

Several renal cell carcinoma molecular markers appear promising to refine the prognosis and prediction of localized, advanced or metastatic renal cell carcinoma. Currently carbonic anhydrase IX is the best studied and promising marker. Prospective, multicenter clinical validation aimed at the practical clinical usefulness of renal cell carcinoma biomarkers is warranted.

Percutaneous Core Biopsy for Renal Masses: Indications, Accuracy and Results

PURPOSE

We evaluated the results, accuracy and clinical incidence of our standard procedure of percutaneous biopsy for solid renal masses.

MATERIALS AND METHODS

From March 1999 to April 2005, 119 percutaneous core biopsies of renal masses were performed. Biopsies were proposed when there was no formal evidence for a carcinoma diagnosis on computerized tomography.

RESULTS

Benign lesions were diagnosed in 24 biopsies (20.1%), including oncocytoma in 13, angiomyolipoma in 5 and chronic pyelonephritis in 5. Malignancy was identified in 70 biopsies (58.8%), including 57 renal carcinomas (conventional renal cell in 41, papillary in 12 and chromophobe in 4), 4 transitional cell carcinomas, 8 metastases and 1 lymphoma. For 25 biopsies (21%) no accurate diagnosis was possible, including 12 that showed inflammatory tissue and 13 with normal or necrotic tissue. These inconclusive biopsies prompted repeat biopsy in 13 patients, in whom a total of 11 malignant lesions were diagnosed. A total of 64 nephrectomies were performed with a biopsy accuracy for histopathological tumor type and Fuhrman nuclear grade of 86% and 46%, respectively. A period of watchful waiting was proposed for 31 patients (34.2%) and no renal malignancies were found. Computerized tomography showed stabilization or disappearance of the initial renal mass.

CONCLUSIONS

Percutaneous renal tumor biopsies are safe, cost-effective and often conclusive for an acute histological diagnosis. This procedure could be decisive for choosing the optimal treatment, particularly to avoid nephrectomy for benign lesions. Biopsies should not be considered a routine procedure but they could be indicated when there is a lack of radiological evidence in elective patients.

Significance of lymphatic invasion and proliferation on regional lymph node metastasis in renal cell carcinoma

We studied the associations of lymphatic invasion and lymphatic vessel density around tumors with lymph node (LN) status in renal cell carcinoma (RCC) by immunohistochemical analysis using D2-40 antibody as a lymphatic marker. Surgically removed specimens from 76 cases with RCC, including 16 cases with LN metastasis, were used. Lymphatic vessel density around the tumor increased compared with normal kidneys but was not significant by LN status. Tumor size, tumor cell types, patterns of tumor growth, nuclear grade of tumor cells, venous invasion, lymphatic invasion, and primary tumor stage were predictive factors for LN metastasis. Based on multivariate regression analysis, only lymphatic invasion was an independent risk factor for LN metastasis. The immunohistochemical detection of lymphatics was useful for identifying the lymphatic invasion of RCC, and the presence of lymphatic invasion around RCC was an independent predictive factor for LN metastasis.

Prognostic Impact of Tumor Size on pT2 Renal Cell Carcinoma: An International Multicenter Experience

PURPOSE

The current tumor classification for renal cell carcinoma classifies pT2 tumors as larger than 7 cm in greatest dimension and limited to the kidney. We examined the current pT2 tumor classification of renal cell carcinoma and determined whether a tumor size cutoff exists that would improve prognostic accuracy.

MATERIALS AND METHODS

We studied 706 patients with pT2 renal cell carcinoma treated with surgical extirpation at 9 international academic centers. Data collected from each patient included age at diagnosis, gender, 2002 TNM (tumor, node, metastasis) stage, tumor size, nuclear grade, performance status, histological subtype and disease specific survival. Disease specific survival was evaluated with univariate and multivariate analysis.

RESULTS

Median followup was 52 months. Univariate Cox regression analysis showed a significant association of tumor size with disease specific survival (HR 1.11, p<0.001). An ideal tumor size cutoff of 11 cm was identified, which led to the stratification of 2 groups with respect to disease specific survival (p<0.0001) with 5 and 10-year survival rates of 73% and 65% for pT2 11 cm or less, and 57% and 49% for pT2 larger than 11 cm, respectively. The incidence of metastases was significantly greater in the larger than 11 cm group, while Eastern Cooperative Oncology Group performance status, Fuhrman grade and histological subtype were similar. Multivariate Cox regression analysis retained tumor size as an independent prognostic factor and as the strongest prognostic factor for patients with pT2N0M0 disease.

CONCLUSIONS

Our data suggest that the current pT2 classification can be improved by subclassification into pT2a and pT2b based on a tumor size cutoff of 11 cm. Patients in the proposed pT2bN0M0 group are at higher risk for death from renal cell carcinoma and should be considered for adjuvant therapies. External validation is warranted before suggesting change to the TNM classification.

Impact of Clinicopathological Parameters in Patients Treated for Renal Cell Carcinoma

PURPOSE

We determined the impact of clinical and pathological factors in the outcome of patients with renal cell carcinoma treated surgically.

MATERIALS AND METHODS

We retrospectively reviewed the records of 230 consecutive patients after radical or partial nephrectomy. We analyzed clinical (incidental or symptomatic disease) and pathological (tumor size, histological type, Fuhrman nuclear grade, microvascular invasion and lymph node involvement) parameters. Disease-free and cancer specific survival curves were individualized for each parameter and on multivariate analysis.

RESULTS

Median postoperative followup was 34.3 months, median time to recurrence was 22 months and mean overall survival was 130 months. A total of 40 patients (17.3%) presented with local and/or metastatic recurrence and 32 (13.9%) died of the disease. Five-year disease-free and cancer specific survival rates on univariate analysis were 56.7% and 64% for symptomatic tumors, 76.6% and 68% for clear cell carcinoma, 26.9% and 39% for sarcomatoid tumors, 34.7% and 47.5% for high grade tumors, 26.7% and 39.7% for microvascular invasion, 37.5% and 49.1% for tumors larger than 7 cm, and 11% and 32% for lymph node involvement, respectively. On univariate analysis patients with lymph node involvement and microvascular invasion had a poor prognosis. Multivariate analysis showed that the single independent prognostic factor was microvascular invasion.

CONCLUSIONS

This study points out different clinical and pathological prognostic factors of survival in patients treated for renal cell carcinoma. Microvascular invasion was the only independent prognostic factor on multivariate analysis.

Prognostic Impact of Perirenal Fat or Adrenal Gland Involvement in Patients with pT3b Renal Cell Carcinoma

OBJECTIVES

To analyze the prognostic impact of the pT3a factors, perirenal fat or adrenal gland involvement, in patients with pT3b renal cell carcinoma (RCC).

METHODS

A total of 43 patients with pT3b RCC who underwent radical nephrectomy, with complete resection of tumor thrombus, at our institution from March 1972 to September 2005 were enrolled in this study. The presence of pT3a factors was reviewed, and the disease-specific survival was compared according to the reclassification as pT3b only or pT3b with pT3a.

RESULTS

After review by a single pathologist, 23 patients (53.5%) were identified as having pT3b only and 20 patients (46.5%) as having pT3b with pT3a. The mean disease-specific survival time in those with pT3b only was significantly longer at 70.9 +/- 9.1 (SE) months compared with 25.0 +/- 4.4 (SE) months in those with pT3b with pT3a (P = 0.0032). On univariate analyses, the presence of pT3a factors (P = 0.0065), preoperative metastasis (P = 0.0025), surgical specimens positive for lymph node metastasis (P = 0.0183), and spindle cell factor (P = 0.0233) were recognized as predictors of a poor prognosis.

CONCLUSIONS

The presence of perirenal fat or adrenal gland involvement in patients with pT3b RCC renders the prognosis significantly worse. Careful postoperative examination should be required, along with reclassification for Stage pT3b with pT3a in RCC.

Serum gamma glutamyl-transferase is a sensitive but unspecific marker of metastatic renal cell carcinoma

OBJECTIVE

To address the role of serum gamma-glutamyl transferase (GGT) as a marker of metastases in patients with renal cell carcinoma.

METHODS

Serum alkaline phosphatase and GGT were determined in 156 patients with localized renal cell carcinoma and 60 patients with metastases as proven by echosonography, computerized tomography and bone scan. The control group consisted of 50 healthy subjects matched for sex and age. Sensitivity and specificity of both enzymes as markers of metastatic disease were compared. In metastatic patients, enzyme activities were analyzed according to the site of metastases.

RESULTS

Both alkaline phosphatase and GGT activities were normal in majority of patients with localized renal cell carcinoma and increased in most of the patients with metastatic disease (80% and 70%, respectively). GGT did not significantly differ from alkaline phosphatase in terms of sensitivity (70% vs 80%) and specificity (89% vs 92%). Concerning the site of metastases, high frequencies of increased GGT and alkaline phosphatase were found in patients with liver-only metastases (80% and 90%, respectively). All of the patients with both liver and bone metastases exhibited increased activity of both enzymes. Despite the fact that bone cells do not express GGT, increased activity was found in patients with bone metastases-only (45%), suggesting that enzymes might be released from tumor cells.

CONCLUSIONS

Our data provided evidence that GGT is a sensitive marker of metastatic renal cell carcinoma. However, findings of abnormal GGT activity cannot specify the site of involvement.

Diagnostic yield of 58 consecutive imaging-guided biopsies of solid renal masses: should we biopsy all that are indeterminate?

OBJECTIVE

The purpose of our study was to report the diagnostic yield of 58 consecutive imaging-guided biopsies of solid renal masses.

MATERIALS AND METHODS

We retrospectively reviewed all percutaneous renal biopsies of solid masses performed at our institution over 83 consecutive months from May 1998 to March 2005 through a query of our radiology department procedure database. Fifty-five CT and three sonographic biopsies were performed at our institution during this time. A solid renal mass was documented prior to biopsy by contrast-enhanced CT (n = 48), gadolinium-enhanced MRI (n = 6), or sonography (solid noncystic masses, n = 4). The average maximal mass diameter was 3.1 cm (range, 1.0-11.0 cm). Forty-seven (81%) of the 58 biopsies were performed immediately before percutaneous ablation. Forty-four (76%) of the biopsies were performed using a coaxial technique with side-cutting automated biopsy needles (16-20 gauge), and 14 (24%) were fineneedle aspirations with a Franseen needle (20 gauge) using a tandem technique. In 19 cases, immunohistochemistry or histochemistry (Hale colloidal iron stain) was used to establish or confirm the diagnosis. Medical records and radiology and pathology reports were reviewed for all patients.

RESULTS

An adequate sample size was obtained in 55 (95%) of 58 renal masses and led to a definitive diagnosis in 52 (90%) of the 58. Renal cell carcinoma accounted for 36 (69%) of 52 diagnostic biopsies. The diagnosis of a benign lesion was made in 14 (27%) of 52 biopsies. Lymphoma (1/58) and metastatic disease (1/58) accounted for the remaining two diagnostic biopsies. Three biopsy samples obtained inadequate sample volumes, and an additional three samples were thought to have adequate sample volume but were not diagnostic. A single false-negative biopsy result was identified after growth was seen on follow-up imaging and subsequent nephrectomy revealed renal cell carcinoma.

CONCLUSION

Imaging-guided biopsy of a solid enhancing renal mass was diagnostic in 52 (90%) of 58 consecutive biopsies. The diagnosis of a benign lesion was made in 27% of diagnostic biopsies. Because of the advances in biopsy and histology techniques, the role of imaging-guided biopsy should be reconsidered.

Modifications of the radiosensitivity of a renal cancer cell line as a consequence of stable TIMP-1 overexpression

PURPOSE

To investigate the potential effects of stable tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) overexpression on DNA damage and cell killing following low-dose gamma-radiation and whether this up-regulation interfered with the activation of the matrix metalloproteinase -2 (MMP-2) and -9 (MMP-9) in a highly metastatic renal carcinoma cell line.

MATERIALS AND METHODS

Stable transfections were carried out using the cytomegalovirus expression plasmid pRc/CMV carrying TIMP-1 cDNA and LIPOFECTAMINE reagent. TIMP-1 expression in selected clones was determined by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot analysis. Exponentially growing Caki-1 cells were treated with sub lethal doses of ionizing radiation (0- 10Gy) either alone or following stable TIMP-1 transfection. DNA damage was assessed by the Alkaline Comet Assay and cell survival was determined by a clonogenic assay. Caki-1 cell cycle alterations following TIMP-1 transfection were assessed by fluorescence activated cell sorting (FACS) analysis of propidium iodide (PI)-stained cells. The interactions between TIMP-1 and MMP-2 and MMP-9 were analysed 24 hours post-irradiation by means of gelatin zymography.

RESULTS

Three clones with varying degrees of TIMP-1 expression were selected and used for further analysis. TIMP-1 transfected Caki-1 cells displayed significantly higher mean tail moment values (p < 0.05) following irradiation at doses between 5 and 10 Gy relative to that seen with radiation alone. The TIMP-1 radiosensitizing effect was accompanied by large decreases in the survival fraction of the parental Caki-1 cell line and significant increases in the alpha-parameter of the linear-quadratic fit. These effects were directly correlated to the degree of TIMP-1 gene expression detected in the selected clones. Interestingly, elevated levels of TIMP-2 protein were detected in the three TIMP-1 clones compared to TIMP-2 levels present in Caki-l cells. The three clones also displayed marked phenotypic alterations relative to their parental cell line. Significant increases in the percentage of cells arrested in the G2/M phase of the cell cycle were detected in the three clones under normal growth conditions and reduced serum conditions (p < 0.05). When the TIMP-1 clones were assessed for their MMP-2 activity, a marked decrease in the MMP-2 mean protein levels was detected in clone T1-3 following irradiation at doses between 2 and 6 Grays (Gy) (p < 0.01) and clone T1-2 at 2- 5Gy (p < 0.05). MMP-9 activity was differentially affected by ionizing radiation in the three TIMP-1 clones. T1-3 and TI-2 displayed significantly reduced MMP-9 levels at various dose points whereas T1-1 exhibited elevated levels of MMP-9 activity at higher doses of treatment (p < 0.05).

CONCLUSION

These results demonstrate a dual role for the TIMP-1 overexpression in this renal carcinoma cell line, both as radiosensitizing agents and effectors of MMP-2 and MMP-9 activity.

CA9 gene expression in conventional renal cell carcinoma: a potential marker for prediction of early metastasis after nephrectomy

About 30-40% of patients with renal cell carcinoma (RCC) will develop metastasis after curative nephrectomy. There is a strong need to identify the early metastasis with conventional and molecular risk factors. The present study aimed to test if analysis of the CA9 gene can provide useful information to predict early metastasis after nephrectomy. This study included 63 patients with a conventional RCC. Ten tumors were N+ or/and M+ at diagnosis. The mean follow-up was 43 months (range, 4-67 months). About 11 M0N0 patients were found to have a metastasis during the follow-up. Quantitative RT-PCR of CA9 gene expression was performed. The metastasis-free survival curve was established according to the Kaplan-Meier method with comparison by the Log-Rank test. At diagnosis, the average of CA9 gene expression was significantly lower (p = 0.004) in metastatic tumors (N+ or/and M+) than in non-metastatic tumors (N0M0). For the follow-up of M0N0 patients, the metastasis-free survival rate was significantly higher (p = 0.005) in the high CA9 group than in the low-CA9 group. When combined with CA9, the metastasis-free survival rates, in terms of stage (p = 0.015) or grade (p = 0.010) were significantly different. When the stage, grade, and CA9 were combined, there was a significant difference (p = 0.004) in metastasis-free survival rates (T1T2 + G1G2 + high expression of CA9 versus T3 + G3G4 + low expression of CA9). Finally, the multivariate regression analysis identified CA9 expression (p = 0.036) as an independent predictor of early metastasis. Our study confirms that the expression level of CA9 gene in conventional RCC is related to metastasis. CA9 may be a potential marker for the prediction of early metastasis after nephrectomy and to guide post-operative follow-up and treatment.