Clinical comparison between vascular and avascular renal cell carcinoma

Foretinib (XL880): c-MET inhibitor with activity in papillary renal cell cancer

Papillary renal cell cancer (RCC) constitutes approximately 10 % of renal cancers and is the commonest form after clear cell RCC, which accounts for approximately 75 % of cases. Until recently, most clinical trials in RCC were open to patients of all histologic types. Very recent clinical trials have been performed predominately in patients with clear cell RCC and relatively few trials have been done for patients with papillary RCC. The clinical characteristics of papillary RCC are less well appreciated because of both its relative rarity in the general oncology population and the lack of related clinical studies. This article reviews papillary RCC as a clinical entity separate from clear cell RCC. The MET signaling pathway, its association with increased invasion and progression of human cancer, and its dysregulation in papillary RCC is discussed. Lastly, foretinib, a multitargeted receptor tyrosine kinase inhibitor of several receptors, including MET and vascular endothelial growth factor receptor 2, is described in preclinical and phase I studies as well as in a phase II study in papillary RCC patients.

Differential expression of prognostic proteomic markers in primary tumour, venous tumour thrombus and metastatic renal cell cancer tissue and correlation with patient outcome

Renal cell carcinoma (RCC) is the most deadly of urological malignancies. Metastatic disease affects one third of patients at diagnosis with a further third developing metastatic disease after extirpative surgery. Heterogeneity in the clinical course ensures predicting metastasis is notoriously difficult, despite the routine use of prognostic clinico-pathological parameters in risk stratification. With greater understanding of pathways involved in disease pathogenesis, a number of biomarkers have been shown to have prognostic significance, including Ki67, p53, vascular endothelial growth factor receptor 1 (VEGFR1) and ligand D (VEGFD), SNAIL and SLUG. Previous pathway analysis has been from study of the primary tumour, with little attention to the metastatic tumours which are the focus of targeted molecular therapies. As such, in this study a tissue microarray from 177 patients with primary renal tumour, renal vein tumour thrombus and/or RCC metastasis has been created and used with Automated Quantitative Analysis (AQUA) of immunofluorescence to study the prognostic significance of these markers in locally advanced and metastatic disease. Furthermore, this has allowed assessment of differential protein expression between the primary tumours, renal vein tumour thrombi and metastases. The results demonstrate that clinico-pathological parameters remain the most significant predictors of cancer specific survival; however, high VEGFR1 or VEGFD can predict poor cancer specific survival on univariate analysis for locally advanced and metastatic disease. There was significantly greater expression of Ki67, p53, VEGFR1, SLUG and SNAIL in the metastases compared with the primary tumours and renal vein tumour thrombi. With the exception of p53, these differences in protein expression have not been shown previously in RCC. This confirms the importance of proliferation, angiogenesis and epithelial to mesenchymal transition in the pathogenesis and metastasis of RCC. Importantly, this work highlights the need for further pathway analysis of metastatic tumours for overcoming drug resistance and developing new therapies.

Papillary renal cell carcinoma: radiologic-pathologic correlation and spectrum of disease

Papillary renal cell carcinoma (pRCC) is the second most common type of renal cell carcinoma (RCC). pRCC has unique imaging and clinical features that may allow differentiation from clear cell RCC (cRCC). There have been significant advances in our knowledge of the natural history and treatment of pRCC, with data suggesting that it may be best to manage pRCC differently from the other subtypes of RCC. At contrast material-enhanced computed tomography, pRCC enhances less than does cRCC in all phases of contrast-enhanced imaging. The difference in the degree of enhancement between pRCC and cRCC is due to differences in their intratumoral vascularity. In general, if a heterogeneous mass enhances to a degree similar to that manifested by the renal cortex, it is likely to be a cRCC. A mass that enhances to a lesser degree is likely to be a non-clear cell RCC. It is common for metastatic lesions from pRCC to show enhancement characteristics similar to those of the primary tumor and be hypovascular.

[Synchronous metastases of the spermatic cord from papillary renal cell carcinoma]

Papillary renal cell carcinoma has been related with higher survival rate and lower metastatic cancer mortality rate than clear renal cell carcinoma. We present an aggressive case related to unusual features for this histological type, like a tumor size higher than ten cm, great perirrenal fat and suprarenal gland infiltration, tumoral thrombosis of the infrahepatic cava vein, retroperitoneal adenopatic tumoral infiltration, high nuclear grade and synchronous solitary distant organ metastases of the right spermatic cord, finding three previous cases in the literature with this last feature. Prognostic implication of the papillary renal cell carcinoma type is unclear in cases like this, so probably we need better molecular and cytogenetic studies to get a correct classification of this histological type.

Contemporary imaging modalities for the surveillance of patients with renal cell carcinoma

In recent years, there have been multiple advances in imaging technologies that have improved the surveillance for recurrence of neoplasms. Multidetector row CT and dynamic contrast enhanced MRI now provide excellent anatomic detail and are beginning to show functional detail as the rapid capture of images following contrast administration improves. Positron emission tomography is emerging as a useful tool in evaluating patients with suspected metastatic disease to the abdomen and bone, particularly when combined with CT. The role of ultrasound in the surveillance of renal cell carcinoma is yet unclear, but its role may be expanding with use of newly developed contrast drugs. Herein we review the relevance of these modalities to the follow-up of patients with renal cell carcinoma.

[Is tumour expression of VEGF associated with venous invasion and survival in pT3 renal cell carcinoma?]

STUDY OBJECTIVE

To determine whether there is a relationship between VEGF expression and renal vein and vena cava invasion in stage pT3 renal cell carcinoma and to evaluate the impact of VEGF expression on survival in pT3 renal cell carcinoma.

MATERIAL AND METHODS

78 patients with a pT3a or pT3b tumour without vena cava invasion or pT3b tumour with vena cava invasion were compared for age, gender, Fuhrman grade and immunohistochemical expression of VEGF. All these variables were submitted to univariate and multivariate analysis to establish their impact on survival.

RESULTS

Only tumour size appeared to be significantly different between the 3 groups. On univariate analysis, invasion of the perirenal fat, lymph node involvement, distant metastases and VEGF expression were significantly associated with survival (p < 0.01). On multivariate analysis, lymph node involvement, distant metastases and VEGF expression (OR 6.07) were identified as independent predictive factors of survival.

CONCLUSION

Progression of a pT3 tumour into the renal vein and vena cava is not associated with increased tumour expression of VEGF. However, VEGF is an independent prognostic factor in this group of poor prognosis renal tumours.

Predicting the Histology of Renal Masses Using Preoperative Doppler Ultrasonography

PURPOSE

Traditional imaging techniques cannot differentiate among benign, indolent and malignant renal neoplasms. Since conventional clear cell carcinomas are highly vascular, we used preoperative color and/or power Doppler ultrasonography to evaluate the association between vascular flow in a renal mass and surgical pathology.

MATERIALS AND METHODS

Nephrectomies performed at our institution between January 2001 and December 2004 were retrospectively evaluated. Any detection of flow in the renal mass on color Doppler ultrasonography was defined as vascular flow. A prospective validation study was then performed from January 2005 to October 2005 and a nomogram was constructed to predict clear cell histology.

RESULTS

Of 299 renal lesions in the retrospective cohort 210 (70%) had evidence of vascular flow, including 156 of 169 conventional clear cell carcinomas (92%) (p <0.0001). On logistic regression analysis vascular flow was associated with conventional clear cell histology (OR 16.9, 95% CI 8.7-32.8; p <0.0001). This finding was validated prospectively in 97 patients. Vascular flow was detected in 54 of 65 renal masses (83%) with conventional clear cell histology (p <0.0001), which was associated with an OR of 10.8 (95% CI 4.0-29.0; p <0.0001). A nomogram incorporating vascular flow along with clinical variables (clinical size, patient sex and age) to predict conventional clear cell histology was constructed on the retrospective cohort and validated on the prospective data set (concordance index 0.82 and 0.76, respectively).

CONCLUSIONS

Vascular flow detected by color Doppler ultrasonography is strongly associated with conventional clear cell histology. A nomogram incorporating vascular flow on color Doppler ultrasonography and clinical parameters may aid in the preoperative characterization of renal lesions.

Serum levels of vascular endothelial growth factor (VEGF) and endostatin in renal cell carcinoma patients compared to a control group

OBJECTIVES

Renal cell carcinoma (RCC) is a vascularised neoplasm. The importance of the angiogenic process in its growth and metastatic spreading is widely recognised. We assessed serum levels of endogenous endostatin and vascular endothelial growth factor (VEGF) in RCC patients and healthy volunteers, and evaluated the factors' prognostic role for patients' survival, distinguishing histologic subtypes with respect to correlation with tumour stage, grade, and size.

METHODS

We considered 146 consecutive patients with RCC and 110 healthy volunteers. Serum samples from all subjects were analysed for endostatin and VEGF by using competitive enzyme immunoassays. RCC samples were compared with serum from the control group and with clinicopathologic factors and clinical outcome.

RESULTS

Mean age was 63 years (range: 37-85 years) in RCC patients and 62 years (range: 23-88 years) in the control group. VEGF levels (median: 3.6 ng/ml+/-6.97; range: 0-48.4 ng/mL) were significantly higher in RCC patients, compared with controls (p=0.001). Endostatin levels did not differ significantly between the two groups (p=0.9) without correlation between endostatin and VEGF levels (p=0.09). No significant difference was found in the endostatin levels among the histologic subtypes (p=0.973) and VEGF (p=0.232). The median follow-up was 27 months (range: 1-57 months).

CONCLUSIONS

Serum VEGF levels are elevated in RCC patients, compared with controls, and do not correlate significantly with circulating endostatin levels. No difference in preoperative serum VEGF and endostatin levels among the different histologic subtypes was found. In multivariate analysis VEGF and endostatin failed to be prognostic; only tumour stage and grade remained independent predictors of survival.

Different isoform patterns for vascular endothelial growth factor between clear cell and papillary renal cell carcinoma

OBJECTIVE

To investigate the protein expression of vascular endothelial growth factor (VEGF) isoforms in relation to the clinical course in patients with different renal cell carcinoma (RCC) types, as angiogenesis is essential for tumour growth and metastasis.

PATIENTS AND METHODS

Western blots were assayed of protein extracts from tumour and concomitant kidney cortex samples from 96 patients. The levels of VEGF189, VEGF165, and VEGF121 isoforms were correlated with clinicopathological characteristics and survival.

RESULTS

VEGF189 levels were significantly higher in kidney cortex and chromophobe RCC than in papillary and conventional RCC. In papillary RCCs, VEGF189 levels correlated inversely with tumour stage and tumour size. VEGF165 levels were higher in kidney cortex than in RCC, but there was no difference among the RCC types. VEGF121 expression was associated with less advanced tumour stage in conventional RCC. Using multivariate analysis, VEGF189 remained as an independent prognostic factor for patients with papillary RCC.

CONCLUSIONS

VEGF189 was associated with tumour progression; in papillary RCC, VEGF189 was a significant independent prognostic factor. VEGF protein isoform patterns differed among the specific RCC types. Additional knowledge is essential to design new anti-angiogenic therapies for all RCC types.

The Expression of Hypoxia-Inducible Factor 1α Is a Favorable Independent Prognostic Factor in Renal Cell Carcinoma

Purpose: Renal cell carcinoma (RCC) is the most common malignancy of the kidney composed of specific tumor types. The sporadic conventional RCCs are, in contrast to the other RCC types, characterized by a high rate of von Hippel-Lindau (VHL) mutations and hypermethylation. The majority of these tumors lack functional VHL protein (pVHL) that leads to increased hypoxia-inducible factor 1α (HIF-1α) expression. The pVHL is the physiologic regulator of the activity of HIF-1α by targeting it to the proteasome for degradation under normoxia. Both pVHL and HIF-1α target other genes that are important for cancer survival and proliferation. Expression of HIF-1α has been linked to poor prognosis in different malignancies, although few studies have been done on the relation between HIF-1α and clinical variables in RCC.

Experimental Design: HIF-1α protein expression was analyzed in tumor tissue from 92 patients with RCC. HIF-1α was quantified by Western blot relative to a positive control.

Results: The HIF-1α protein was expressed as two bands which strongly correlated (r = 0.906, P &lt; 0.001); therefore, they were added and the sum evaluated against clinicopathologic variables. There was no association between HIF-1α and gender, stage, grade, tumor size, or vein invasion. Conventional RCCs had significantly higher HIF-1α expression compared with papillary and chromophobe RCCs and kidney cortex. In conventional RCC, HIF-1α was an independent prognostic factor.

Conclusion: HIF-1α levels varied significantly between the different RCC types. In conventional RCC, HIF-1α was an independent prognostic factor. These data indicate that HIF-1α is involved in tumorogenesis and progression of RCC. Evaluation of other HIF target gene products and correlation to angiogenesis seems warranted.

Differentiation of Renal Clear Cell Carcinoma and Renal Papillary Carcinoma Using Quantitative CT Enhancement Parameters

OBJECTIVE

The purpose of our study was to evaluate quantitative multiphasic CT enhancement patterns of malignant renal neoplasms to enable lesion differentiation by their enhancement characteristics. We used a new method to standardize enhancement measurement in lesions on multiphasic CT not being influenced by intrinsic factors like cardiac output.

CONCLUSION

The new correction method is a simple tool for excluding intrinsic influences on the enhancement of lesions. Quantitative enhancement evaluation with this method of the influence of intrinsic factors enables accurate differentiation between renal clear cell carcinoma and renal papillary carcinoma.

Interleukin-6, interleukin-10, and vascular endothelial growth factor in metastatic renal cell carcinoma: prognostic value of interleukin-6--from the Groupe Francais d'Immunotherapie

PURPOSE

Few clinical prognostic factors have been identified for patients with metastatic renal cell carcinoma (MRCC), and no biomarker is known in this disease. Several endogenous cytokines have demonstrated interesting and significant correlations with survival in these patients. Our objective was to analyze the prognostic value of circulating vascular endothelial growth factor (VEGF), interleukin-10 (IL-10), and interleukin-6 (IL-6).

PATIENTS AND METHODS

Serum levels of IL-6, IL-10, and VEGF were measured in patients with MRCC. Their prognostic value for response to treatment and progression-free and overall survival was evaluated. Pretreatment samples were obtained from 138 patients of a large randomized multicentric trial. Endogenous cytokine levels were determined using immunoassays. Univariate and multivariate analyses were performed to evaluate the prognostic value of each factor further controlled by an internal validation test. Threshold values for serum IL-6 and VEGF were determined using the quartile method.

RESULTS

Serum IL-6 was detectable in 70% of the patients. IL-10 and VEGF were elevated in 8% and 71% of the patients, respectively. None of these circulating factors was correlated with response to treatment. IL-10 was not significantly correlated with progression-free or overall survival. Despite significant correlation with survival, VEGF was not an independent prognostic factor in the multivariate analysis. Finally, IL-6 was significantly correlated with progression-free survival and overall survival, and has prognostic value for overall survival.

CONCLUSION

Circulating IL-6 level appears to be an important independent prognostic factor in patients with MRCC; if confirmed in further studies, it could be considered for treatment decisions in these patients.

Expression of vascular endothelial growth factor protein in human renal cell carcinoma

OBJECTIVE

To evaluate the effect of vascular endothelial growth factor (VEGF, one of the most important angiogenetic factors) in renal cell carcinoma (RCC) by analysing many RCCs for the expression of immunohistochemical (IHC) VEGF-staining related to clinicopathological findings and survival.

PATIENTS AND METHODS

VEGF immunostaining was examined with the tissue microarray (TMA) method on tumour samples from 229 patients and validated in 71 by ordinary tissue sections (TS). IHC VEGF expression was quantified by estimating the volume density and staining intensity on a three-grade scale.

RESULTS

In most RCCs there was VEGF staining in the cell cytoplasm and membrane. In cell membranes the VEGF expression declined with storage time. IHC VEGF expression analysed by TMA and TS gave corresponding results. There was no difference in VEGF expression among conventional, papillary and chromophobe RCCs. There were significant correlations between VEGF expression and tumour size and stage. In univariate analysis VEGF expression correlated with survival, especially in conventional RCCs; this prognostic information was lost in multivariate analysis. The VEGF staining intensity correlated only with VEGF expression but not with any clinicopathological factors.

CONCLUSIONS

VEGF protein was present in most RCC cells. There was no difference in VEGF expression among the different RCC types. The correlation between VEGF expression and tumour stage and with prognosis indicates the significance of VEGF within tumour growth and progression in RCC.

Overproduction of vascular endothelial growth factor related to von Hippel-Lindau tumor suppressor gene mutations and hypoxia-inducible factor-1 alpha expression in renal cell carcinomas

PURPOSE The von Hippel-Lindau (VHL) tumor suppressor gene is frequently inactivated in the common type of sporadic clear cell renal cell carcinoma (RCC) as well as RCCs associated with VHL disease. The VHL protein targets hypoxia-inducible factor-1 alpha (HIF-1 alpha), a transcription factor that can induce vascular endothelial growth factor (VEGF) expression, for ubiquitination and degradation. Accumulation of HIF-1 alpha caused by mutant VHL protein in tumor cells may result in VEGF over expression, which has been used to explain the increased vascularity of RCC. However, quantitative analyses of VEGF production and its correlation with VHL mutations and HIF-1 alpha expression in authentic tissues from patients with RCC are lacking.

MATERIALS AND METHODS

We analyzed VHL gene mutations by direct DNA sequencing and methylation specific polymerase chain reaction in 31 paired RCC tissue samples. HIF-1 alpha protein expression detected by immunoblotting and immunohistochemical staining, and VEGF protein measured by enzyme-linked immunosorbent assay and immunohistochemical staining were performed using tumor and corresponding normal tissues.

RESULTS

VHL gene mutations were detected in 44% of clear cell RCCs but no differences in methylation patterns in the promoter or exon 1 were found. RCCs with VHL gene mutations or of advanced grade produced significantly higher concentrations of VEGF (p <0.0001). HIF-1 alpha protein expression was found in 40% of clear cell RCCs but 80% of them had VHL mutations (p <0.006). HIF-1 alpha expression correlated directly with higher levels of VEGF production (p <0.0001).

CONCLUSIONS

Our findings indicate that VHL gene alterations and HIF-1 alpha protein expression correlate with a significant increase in VEGF production by RCC. In turn it is associated with a more aggressive tumor phenotype.

Thrombospondin-1, vascular endothelial growth factor expression and microvessel density in renal cell carcinoma and their relationship with multifocality

OBJECTIVE

To evaluate the relevance of microvessel density (MVD) and the angiogenic factors, vascular endothelial growth factor (VEGF, an important angiogenic factor in solid tumors) and thrombospondin-1 (TSP-1, a potent inhibitor of angiogenesis), to multifocality of renal cell carcinoma (RCC).

PATIENTS AND METHODS

Using immunohistochemistry the expression of CD34, TSP-1 and VEGF was assessed in 38 archival tissue specimens from 19 patients with unifocal RCC and 19 with multifocal RCC. Immunostaining results for VEGF was scored for the appropriate percentage of positive tumor cells and relative immunostaining intensity (score range 0-12). Only extracellular immunoreactivity was considered positive for TSP-1 and the same method was used to score the stromal staining. The microvessel density was measured by immunohistochemical staining with anti-CD34 monoclonal antibody.

RESULTS

VEGF immunoreactivity> or =1% was detectable in all unifocal and multifocal tumors. TSP-1 immunoreactivity was detected in 14 (73.7%) of 19 unifocal RCCs and in 16 (84.2%) of 19 multifocal RCC specimens (p=0.69). There were no statistically significant differences in the immunostaining intensity, percentage of immunopositive cells and the staining scores of VEGF and TSP-1 among the two groups. Additionally, there was no difference in MVD in multifocal and unifocal tumors.

CONCLUSION

As there is no difference in MVD count, and expression of angiogenic factors (VEGF and TSP-1) in multifocal and unifocal tumors, multifocality of RCC is not determined by VEGF/TSP-1 expression.

Thymidine phosphorylase levels as a prognostic factor in renal cell carcinoma

OBJECTIVE

To investigate the relationship between thymidine phosphorylase (TP), a vascular growth factor, and established prognostic factors for renal cell carcinoma (RCC), e.g. histological grade or Tumour-Node-Metastasis (TNM) classification.

PATIENTS AND METHODS

TP levels were measured in RCC tissue (tumour TP) and in adjacent non-neoplastic kidney tissue (normal tissue TP), using a sandwich-type enzyme-linked immunosorbent assay. The 59 patients, diagnosed with organ-confined RCC before surgery and who had undergone radical nephrectomy, were divided into two groups according to their prognosis after surgery. Group 1 (nine patients) had a poor prognosis and group 2 (50) had no evidence of disease within a 65-month follow-up. The relationships among TP level, TNM classification, histological subtypes, V factor and prognosis, and of tumour TP to normal tissue TP levels were investigated. Multiple regression analysis was used to determine the importance of factors associated with increased TP levels.

RESULTS

Normal tissue TP levels correlated with histological grade (r = 0.31, P < 0.01); in patients with venous invasion or with a poor prognosis, the levels were significantly higher than in those without (P < 0.05 and < 0.001, respectively). The normal tissue TP levels were also significantly higher in the non-clear cell than in the clear cell subtype. Multiple regression analysis showed that the independent factor associated with elevated normal tissue TP levels was histological grade (R2 = 0.189, P < 0.01). There was no correlation between tumour TP and other factors.

CONCLUSION

Normal tissue TP levels in localized hypervascular RCC were associated with histological grade. These data suggest that normal tissue TP levels could be a prognostic factor.

Enhancement characteristics of papillary renal neoplasms revealed on triphasic helical CT of the kidneys

OBJECTIVE

The purpose of this study was to determine whether renal tumor enhancement or heterogeneity on triphasic helical CT scans is predictive of the papillary cell subtype or nuclear grade of renal cell carcinoma.

MATERIALS AND METHODS

We reviewed the CT scans of 90 consecutive patients with renal masses who had undergone triphasic renal helical CT before a complete or partial nephrectomy (12 with papillary renal cell carcinomas, 66 with nonpapillary renal cell carcinomas, and 12 with benign lesions). Three radiologists who were unaware of the patients' diagnoses retrospectively and independently measured the attenuation of each patient's tumor, abdominal aorta, and normal renal parenchyma on the scans obtained during all three phases. Ratios of tumor-to-aorta enhancement and tumor-to-normal renal parenchyma enhancement were calculated for both of the phases performed after contrast material had been administered. Tumor heterogeneity was calculated as the difference between the highest and lowest attenuation values divided by the value of the enhancement of the aorta. Values were correlated with cell type and nuclear grade found at surgical pathology.

RESULTS

Low tumor-to-aorta enhancement and low tumor-to-normal renal parenchyma enhancement ratios on the vascular phase scans significantly correlated (p < 0.001) with papillary renal cell type carcinoma. Homogeneity and tumor-to-parenchyma enhancement ratios on the parenchymal phase scans also significantly correlated (p < 0.001) with papillary renal cell type carcinoma. Heterogeneity and tumor enhancement ratios did not correlate with the nuclear grade of the carcinoma.

CONCLUSION

Papillary renal cell carcinomas are typically hypovascular and homogeneous. A high tumor-to-parenchyma enhancement ratio (> or = 25%) essentially excludes the possibility of a tumor being papillary renal cell carcinoma. A low tumor-to-aorta enhancement ratio or tumor-to-normal renal parenchyma enhancement ratio is more likely to indicate papillary renal cell carcinoma.

Radiologic, pathologic and molecular attributes of two types of papillary renal adenocarcinomas

OBJECTIVE

Most papillary renal tumors are not as aggressive as clear cell carcinomas and thus carry a better prognosis. However, several reports in the literature have demonstrated a subset of patients with papillary tumors that have a more aggressive biology and advanced stage at presentation. We compared several parameters of these subsets of renal tumors in an effort to characterize these lesions.

PATIENTS AND METHODS

We reviewed 391 cases of nephrectomies that were performed for cancer over a 20-year period from four institutions. Of these, 41 were documented as papillary adenocarcinomas. We reviewed these cases with respect to stage at presentation, size, vascularity on (computerized tomography) CT scan, histology, and cytokeratin immunohistology.

RESULTS

Thirty-two of the lesions presented in the fifth, sixth, seventh and eighth decades of life (Type I), while most of the remaining 9 tumors (Type II) presented in the fourth decade of life, and in more advanced stages. Tumor volumes ranged from 84 cm3 to 1660 cm3. Type I tumors had an average size of 515 cm3 and an enhancement on CT of 36 +/- 4 Hounsfield units, compared with Type II tumors which had an average size of 164 cm3 and an enhancement on CT of 92 +/- 8 Hounsfield units. Type II tumors also had a higher mean Fuhrman score of nuclear pleomorphism than Type I, and a greater expression of cytokeratin.

CONCLUSIONS

We found that the more common Type I variant of papillary renal adenocarcinoma was less vascular on CT scan, larger in size, and had a lower amount of nuclear pleomorphism as well as decreased expression of cytokeratin 7. The more aggressive biological variant, Type II, presented in the earlier decades of life, with a smaller, but more vascular, cancer and had a greater nuclear pleomorphism. Nuclear pleomorphism still appears to have the best prognostic assessment. However, other molecular and genetic parameters of these tumors, as well as long-term survival data will be necessary to determine the significance of these findings.

Double-phase helical CT of small renal parenchymal neoplasms: correlation with pathologic findings and tumor angiogenesis

PURPOSE

To correlate the enhancement pattern of double-phase helical computed tomography (CT) of small renal parenchymal neoplasms with pathologic findings and tumor angiogenesis, and evaluate whether the enhancement pattern would be useful in differentiating the histomorphologic types of small renal parenchymal neoplasms.

MATERIALS AND METHODS

Double-phase helical CT (5 mm slice) of the corticomedullary phase (CMP) and late nephrographic phase (NP) was performed in 40 surgically resected renal neoplasms <3.5 cm. The patterns of CT attenuation value and homogeneity were correlated with the subtypes of neoplasms, microvessel density, and the existence of intratumoral necrosis or hemorrhage.

RESULTS

Clear cell renal cell carcinomas (RCC) (n = 29) showed a peak attenuation value in the CMP of >100 HU [Hounsfield units]. Chromophobe cell RCC (n = 2) showed a peak attenuation value in the CMP of <100 HU. Papillary RCC (n = 5) showed a gradual enhancement with the attenuation value in the CMP of <100 HU. However oncocytomas (n = 2) and metanephric adenomas (n = 2) also showed patterns similar to these subtypes of RCC. The degree of enhancement in the CMP correlated with microvessel density (r = 0.87). All tumors with an homogeneous enhancement pattern did not show necrosis or hemorrhage on histologic specimen.

CONCLUSION

The enhancement pattern in double-phase helical CT was different among the subtypes of RCC, and correlated with microvessel density or the existence of intratumoral necrosis or hemorrhage. However it did not differentiate between RCC and other solid tumors.

Vascular endothelial growth factor as prognostic factor in renal cell carcinoma

PURPOSE

Vascular endothelial growth factor (VEGF) has been recognized as an important constituent of vascularization and growth of solid tumors. Serum VEGF levels were evaluated and correlated to clinicopathologic findings and clinical outcome in patients with renal cell carcinoma (RCC).

MATERIALS AND METHODS

Serum samples were collected before surgery in 164 patients with RCC. Levels of VEGF165 protein in sera were measured using a quantitative ELISA. Univariate and multivariate analyses were performed.

RESULTS

The VEGF165 level in serum was significantly increased (p = 0.0001) in patients with RCC (median 343.4 pg./ml.) compared with the control patients (median 103.8 pg./ml.). The level of VEGF165 in serum correlated to clinical stage and histopathological grade. Patients with VEGF165 levels below median value had significantly longer survival time than patients with higher levels (p = 0.0001). This was also shown when VEGF165 was analyzed in univariate Cox regression (p = 0.0001). The impact of VEGF165 on survival was especially shown in patients having tumors with vein invasion (pT3b-c N0 M0) and in patients with clinical stages I - III (p = 0.0240 and p = 0.0023, respectively). When using multivariate analysis, only tumor stage and grade remained as independent prognostic variables.

CONCLUSIONS

In RCC, serum VEGF165 level was significantly correlated to tumor stage and grade. Increased levels were correlated to adverse survival. Although, VEGF did not remain as an independent prognostic factor in multivariate analysis the levels of VEGF165 in serum was found useful for the identification of patients with potentially progressive disease especially for those with vein invasion.

DNA ploidy pattern in papillary renal cell carcinoma. Correlation with clinicopathological parameters and survival

Papillary renal cell carcinoma (PRCC) is a less frequent histomorphologic variant of renal cortical carcinoma (RCC). Morphologically, PRCC differs from other forms of RCC in that it is associated with frequent tumor infiltration by macrophages and lymphocytes, and a tendency for central necrosis and cystic change. Follow-up data revealed that survival rates are higher among patients with PRCC than among patients with other forms of RCC. The authors explore the DNA content in a series of PRCC and correlate the findings with nuclear grade, pathological stage and survival. Using Flow Cytometry, we analysed the DNA ploidy pattern of 37 paraffin-embedded PRCC. At least 3 tumor fragments were analysed in each case. To obtain the reference diploid standard, the non-tumor renal tissue from the same case was added to the solution. Tumor ploidy was classified as diploid and aneuploid. The degree of DNA content abnormalities was given by the DNA Index (DI). An aneuploid DNA profile was found in 65% of the tumors. 25% of the aneuploid tumors presented near diploid peaks (1.10 < DI < 1.30; low degree aneuploidy), 25% were hyperdiploid, while 22% had a hypodiploid profile (DI < 0.90). A homogeneous DNA ploidy pattern was observed in 25 tumors (68%), while there was intratumoral heterogeneity in 12 tumors (32%). Patients with aneuploid DNA patterns had high grade/stage tumors and died at the end of the follow-up period, while patients with diploid/near diploid profiles had low grade/stage tumors and survived. However, the multi-way analysis of variance performed in order to investigate the prognostic significance of ploidy pattern against tumor stage and grade showed a highly significant main effect of ploidy pattern. Moreover, the patients with hypodiploid DNA profile presented the worst prognosis. These results suggest that the DNA profile of PRCC is a highly significant prognostic index.

Imaging features of hereditary papillary renal cancers

PURPOSE

Our goal was to describe the imaging features of hereditary papillary renal cancer syndrome (HPRC), a new familial cancer syndrome.

METHOD

Members of seven kindreds with HPRC comprising 78 individuals were screened with contrast-enhanced CT and abdominal US. MRI was performed in three patients. Enhancement values and doubling times of solid masses were determined from CT scans.

RESULTS

Seventeen of 78 (22%) patients were affected. The HPRCs demonstrated lower enhancement (mean change in enhancement = 31 HU) than a comparable group of clear cell tumors (mean change in enhancement = 67 HU: p = 0.00001). The median tumor doubling time on serial CT was 18 months. The HPRCs were relatively hypovascular, enhanced uniformly, and grew slowly. Therefore, careful measurements of the region of interest should be obtained before and after intravenous administration of contrast medium. Though US detected only 45% of the lesions visualized on CT, it was useful in determining if lesions were cystic. Contrast-enhanced MRI demonstrated similar characteristics to contrast-enhanced CT.

CONCLUSION

The tumors of patients with HPRC pose some diagnostic difficulties because they can be missed by US, are small, and enhance poorly on CT. CT is preferable to US as a screening tool because of its higher sensitivity in detecting small lesions, and when contrast media cannot be administered, MR is a suitable alternative to CT.

Papillary (chromophil) renal cell carcinoma: histomorphologic characteristics and evaluation of conventional pathologic prognostic parameters in 62 cases

For more than two decades, papillary renal cell carcinoma has been recognized as a possible distinct clinicopathologic subtype of renal cell carcinoma (RCC). However, the histologic criteria for its diagnosis and the clinical outcome are still debated. In an attempt to clarify the diagnostic criteria and resolve issues pertaining to biologic potential, we have evaluated the histologic spectrum of 62 papillary RCCs and assessed significance of conventional pathologic prognostic parameters (Fuhrrman's nuclear grade [NG], pathologic stage [Robson and TNM], tumor size, multifocality, necrosis, and foam cells) and correlated these with outcome. The mean age of patients was 61.8 years (range 22-83), and males were more commonly affected (1.8:1). Grossly, most tumors were well circumscribed, averaged 6.7 cm in size (range 1.8-18), and were predominantly localized to the renal poles (polar vs. mid-renal, 3:1). Multifocality was a prominent feature (24 cases), and in three cases tumors were bilateral. Microscopically, papillary RCCs were predominantly papillary or tubulopapillary, often with a thick fibrous capsule, foam cells, necrosis, hemorrhage, and multifocality. Thirty-five percent of these tumors were low grade (NG I and II) and 65% high grade (NG III and IV). Sixteen of these tumors presented in a higher stage (stages III and IV), and the overall stage correlated with NG (chi 2, p = 0.009). Tumors were further distinguished by cytoplasmic features: eosinophilic (42%), basophilic (34%) and mixed (24%). Eosinophilic tumors were predominantly high grade, and basophilic tumors low grade (chi 2, p = 0.000). A mean follow-up of 57 months showed progression (metastasis, recurrence, or death due to disease) in 21%, whereas 63% were free of disease. Eleven percent died of unrelated causes, and 5% were lost to follow-up. Kaplan-Meier survival analysis showed that both high NG and stage were strongly associated with decreased survival (p = 0.0000 each), as were decreased foam cell (p = 0.0025) and vascular invasion (p = 0.0002). Comparison of 196 reported cases of papillary RCC, including the current series, with reported large series of conventional RCC indicates that papillary RCC usually presents at an early stage, and stage I (Robson) papillary RCC has better 5 year survival rates (87%-100%) than does RCC of the same stage (65-75%). The overall 5 years survival rate for papillary carcinoma (82-90%) was also higher than that of conventional RCC (44-54%). In a Cox proportional hazard regression model, TNM stage appeared to be the only significant variable (p = 0.0000, hazard ratio 10.1) in predicting outcome among papillary RCC. Based on this experience, we conclude that (a) papillary RCC is a malignant tumor, with a tendency to present at a lower stage, but with a distinct potential for progression and aggressive behavior; (b) stratification of these tumors according to cell type, amount of foam cells, presence or absence of vascular invasion, nuclear grade, and pathologic stage provides useful prognostic information; (c) the better 5-year survival rate of papillary RCC (overall and for stage I tumors) compared with that of conventional RCC suggests that it is a tumor with lower malignant potential. Thus, histologic subcategorization of a renal carcinoma as papillary RCC appears to have prognostic implications.

Renal cell carcinoma: prognostic factors

OBJECTIVE

To establish the prognostic value of a series of pre-operative, per-operative and histopathological parameters in relation to renal cell carcinoma (RCC).

PATIENTS AND METHODS

This retrospective study involved a consecutive series of 76 patients (46 men and 30 women with a mean age of 65.3 years [range 44-91]) with a histologically confirmed diagnosis of RCC. Patients who were admitted over the period 1980-1984 were included. Data such as erythrocyte sedimentation rate (ESR), alkaline phosphatase level, histological tumour grade, degree of necrosis and presence of tumour vessels were evaluated in relation to actuarial survival.

RESULTS

The ESR and alkaline phosphatase level at the time of diagnosis of RCC, the histological tumour grade, degree of necrosis and presence of tumour vessels on angiography were all found to affect the actuarial length of survival significantly (P < or = 0.05 log-rank test). Macroscopic tumour demarcation estimated per-operatively by the surgeon or after surgery by the pathologist, microscopic demarcation, vascular density on histological examination, tumour diameter and vascular density on angiography were found not to affect actuarial survival significantly.

CONCLUSION

The value of establishing simple and reliable diagnostic indicators for patients with RCC is stressed.

Papillary renal cell carcinoma: clinical implication of DNA content analysis

Papillary renal cell carcinoma is considered a less-aggressive histomorphologic variant of renal cell carcinoma. We investigated the clinicopathologic features and the DNA ploidy pattern in 22 papillary renal cell carcinoma cases and correlated the findings to the patients' length of survival. In this study the demographic data were similar to those of previously published series. Histologically, two neoplasms were Fuhrman's nuclear grade 1, eight were nuclear grade 2, 11 were nuclear grade 3, and one was nuclear grade 4. Six tumors were stage I, three were stage II, five were stage III, and eight were stage IV. With a mean follow-up period of 42 months, eight patients died of disease and 14 were alive and well. DNA aneuploidy was found in 50% of the neoplasms and was frequently associated with high tumor nuclear grade, high tumor stage, and poor prognosis. Conversely, DNA diploidy was preponderantly noted in neoplasms with low tumor nuclear grade and stage, and none of the patients died of their disease. A statistically significant difference between DNA ploidy/tumor stage and patient outcome was obtained. No significant correlation between DNA ploidy and nuclear grade was observed. Our results suggest that DNA content measurements may assist in evaluating the clinical outcome of this neoplasm. Moreover, they indicate that papillary renal cell carcinomas manifest clinicopathologic, DNA content, and biologic characteristics akin to those of nonpapillary variants.

A prospective study of the value of conventional CT, dynamic CT, ultrasonography and arteriography for staging renal carcinoma

The value of dynamic CT scanning for staging renal carcinoma was studied prospectively in 28 patients and the results compared with those of ultrasonography, arteriography and conventional CT. Arteriography correctly staged 48% of tumours; ultrasonography and conventional CT correctly staged 50% and dynamic CT correctly staged 72%. Dynamic CT staged renal carcinoma more accurately than ultrasonography, conventional CT or arteriography and it is suggested that arteriography should be restricted to specific indications such as the mapping of arterial anatomy and therapeutic renal artery embolisation.

Renal cell carcinoma. II. Histological indicators of prognosis

Tissue obtained from 102 renal tumours presenting over a 21-year period was reviewed in an attempt to identify histological features of prognostic importance. Statistical analysis showed the grade of nuclear pleomorphism to have a significant bearing on survival. Application of the proportional hazard model, and using the grade of nuclear pleomorphism as a baseline index, showed mitotic rate, pseudocapsule thickness and the presence of sarcomatoid tumour cells to have an independent association with survival. The presence of tumour cells with granular cytoplasm was correlated with outcome; however, this parameter was not independent of grade of nuclear pleomorphism. Tumour pattern, intensity of lymphocytic infiltrate, degree of fibrosis, necrosis and hemorrhage, and amount of haemosiderin and dystrophic calcification were found to have no association with survival.

Oncologic imaging: kidney and ureter

Malignant cancers of the kidney and ureter account for only 2-3% of all neoplasms in man. However, early diagnosis and treatment can have a profound effect on patient prognosis and survival. This article seeks to amalgamate a large body of information related to the pathology or primary renal tumors and metastatic disease with current imaging strategies to assist the clinician and enhance his understanding of the wide variety of modern imaging techniques available. Current tumor staging classifications are presented and the various imaging strategies are keyed to detection, definition and treatment options for tumors of the renal parenchyma and ureter. The strengths and limitations of all available imaging modalities are reviewed. An optimal approach to the imaging work up is developed with regard to availability, evolving technology and most importantly, cost efficacy. The controversies and conflicts in imaging and treatment options are explored while constructing a step by step approach that will be both flexible and utilitarian for the clinician faced with daily oncologic management choices.

Papillary renal cell carcinoma: ultrasonic/pathologic correlation

Papillary renal cell carcinoma represents a separate clinicopathologic entity distinguished from nonpapillary renal cell carcinoma by angiography, microscopic pathology, and biological behavior. We correlated retrospectively 11 surgically proven papillary renal cell carcinomas with ultrasound patterns and gross pathologic findings. In addition, we reviewed retrospectively 65 surgically proven cases of nonpapillary renal cell carcinoma for sonographic patterns. Seven of 11 (64%) of the papillary tumors were less echogenic than the ipsilateral renal cortex (hypoechoic). Only 23% of the nonpapillary tumors were hypoechoic. These data suggest that renal papillary carcinoma tends to be hypoechoic on ultrasound. In most of the papillary cases, this hypoechoic pattern was due to a large central area of cystic necrosis within the tumor.

Renal carcinoma: computer analysis of 96 patients treated by nephrectomy

We submitted to computer analysis 109 items of pathologic, clinical and survival data from 96 patients with renal carcinoma treated by nephrectomy with or without adjuvant therapy between 1956 and 1976. The combined 1, 5 and 10-year calculated survival rates for potentially curable non-metastatic renal carcinoma (stages I, II and III, provided the regional lymph nodes were not involved) were 95, 61 and 47 per cent, respectively, compared to 1, 5 and 10-year survival rates of 61, 5 and 0 per cent, respectively, for stage IV tumors. The cytoplasmic appearance (clear or granular) was not a significant microscopic feature relevant to survival of the patient but the grade of the tumor was predictive of the outcome of disease. Other features of renal carcinoma, particularly invasion of the renal vein and, to a lesser degree, perinephric fat, were not as prognostically significant in this series. In this retrospective study we further analyze the clinical, radiologic, pathologic and survival data of this group of patients.

Spontaneous retroperitoneal hemorrhage from a ruptured hypernephroma

The clinical presentation and roentgenographic findings of renal cell carcinoma have been consistently variable. These patients can appear with flank pain mimicking ureteral colic, flank tumors, or symptomatic metastasis [1]. Systemic cardiac manifestations including cardiomegaly with congestive heart failure due to arteriovenous fistula formation have been reported [2] Roentgenographic findings may show the tumor to be either vascular or avascular. It may present as a spontaneous perforation of the pelvic ureteral system which is demonstrated by intravenous pyelography (3). In this article, we describe a case of hypernephroma in a cyst wall causing severe spontaneous hemorrhage in the retroperitoneal space resulting in a state of hypovolemic shock.

Renal papillary adenocarcinoma

Papillary adenocarcinoma of the kidney is an uncommon variant of renal tubular carcinoma, which on radiographic and ultrasonographic evaluation presents characteristically as a predominantly solid hypovascular or avascular mass. Surgery is required to distinguish this lesion from other solid renal lesions, which differs from the more common form of renal tubular carcinoma in several important respects.

Papillary renal cell carcinoma: a clinical, radiologic, and pathologic study of 34 cases

Papillary renal cell carcinoma (RCC) is known by its tendency to avascularity by angiography; however, data concerning its clinicopathologic spectrum and prognosis are not available. In a review of 224 renal cell carcinomas accesioned in our files, 34 were found to be papillary and 190 of other histologic types. A comparative analysis of these two gropus revealed marked differences. The majority of papillary tumors (85.3%) were in pathologic stage I, whereas more than half of the nonpapillary tumors had extended beyond the limits of the kidney. Follow-up data revealed that the survival for papillary RCC was significantly higher than that for nonpapillary tumors. This difference held true even when tumors in the same pathologic stage were compared. Many papillary tumors, particularly those with a favorable course, were massively necrotic, densely infiltrated by macrophages, or both. In view of these findings, the possibility that host mechanisms are involved in destruction and confinement of the tumor is discussed. Examination of kidney tissue distant from the tumor disclosed, in some cases, atypical hyperplastic changes of collecting tubules; this raises the possibility that some papillary tumors arise from distal tubular epithelium. Hypo- or avascularity was present in all papillary RCC's studied by angiography.