The prevalence of renal cell carcinoma: a nation-wide survey in Japan in 1997

Radiation Risks for the Incidence of Kidney, Bladder and Other Urinary Tract Cancers: 1958-2009

As part of the recent series of articles to create a comprehensive description of the radiation risks of solid cancer incidence after ionizing radiation exposure, based on the atomic bomb survivors' Life Span Study (LSS), this work focuses on the risks of urinary tract cancer (UTC) and kidney cancer. Analyses covered a 52-year period of follow-up, through 2009, among 105,444 eligible survivors who were alive and cancer free in 1958. This represents an additional 11 years of follow-up since the last comprehensive report, with a total of 3,079,502 person-years. We observed 790 UTC and 218 kidney cancer cases. Adjusted for smoking, there was a strong linear radiation dose response for UTC. The sex-averaged excess relative risk per 1 Gy (ERR/Gy) was 1.4 (95% confidence interval, CI: 0.82 to 2.1). Both males and females showed significantly increased ERRs/Gy with female point estimates at a factor of 3.4 (95% CI: 1.4 to 8.6) greater than male estimates. UTC radiation risks were largely unmodified by age at exposure or attained age. The attributable fraction of UTC to radiation exposure was approximately 18% while that attributed to smoking was 48%. Kidney cancer showed an increased ERR due to smoking (0.56 per 50 pack-years; 95% CI -0.007 to 1.6; P = 0.054), but we did not observe any strong associations of kidney cancer with radiation exposure, although sex-specific dose responses were found to be statistically different.

Clinicopathological characteristics and oncological outcomes in patients with renal cell carcinoma registered in 2007: The first large-scale multicenter study from the Cancer Registration Committee of the Japanese Urological Association

OBJECTIVES

To describe the clinicopathological features and oncological outcomes of renal cell carcinoma diagnosed in Japan in 2007, the results of the large-scale renal cell carcinoma registration study carried out by the Japanese Urological Association are reported.

METHODS

The renal cell carcinoma survey was carried out by the Japanese Urological Association in 2012 to register newly diagnosed renal cell carcinoma cases in 2007 from 340 institutions nationwide. The survey included clinicopathological details, such as sex, age, family history, past history, smoking history, body mass index, reason for diagnosis, TNM classification, stage, histopathology, treatment and clinical outcomes.

RESULTS

A total of 3663 cases diagnosed in 2007 were registered in this renal cell carcinoma registry program from 340 institutions. A total of 15 patients with a final diagnosis of oncocytoma were excluded, and 3648 cases of renal cell carcinoma were analyzed to evaluate oncological outcomes. The patients' median age was 63.9 years (range 5.9-95.1 years). Clear cell renal cell carcinoma was the most common histological subtype (77.2%), followed by papillary (5.0%) and chromophobe (3.2%) renal cell carcinoma. The most common initial treatment was radical nephrectomy (72.6%), and the most common secondary treatment was cytokine therapy (13.1%). Five-year overall survival rates in stages I, II, III, and IV were 94.8%, 90.2%, 78.8% and 39.6%, respectively. The 5-year overall survival rates for clear cell, papillary and chromophobe renal cell carcinomas, and carcinoma of the collecting ducts of Bellini were 88.6%, 79.8%, 93.0% and 40.0%, respectively.

CONCLUSIONS

The present report is the first nationwide large-scale study to describe the clinicopathological characteristics and oncological outcomes of patients with renal cell carcinoma in Japan. Oncological outcomes depend on the clinical stage and histological subtype. Further investigations will be required to show improved oncological outcomes in the molecular targeted therapy era using the results of the present study as a baseline.

Apolipoprotein A1 -75 G/A and +83 C/T polymorphisms and renal cancer risk

Background

Apolipoprotein A1 (ApoA1) is the major apoprotein constituent of high-density lipoprotein that can play important roles in tumor invasion and metastasis. The objective of the present study was to evaluate the association of two genetic variants (−75 G/A and +83 C/T) of APOA1 with predisposition to renal cancer.

Methods

A total of 432 subjects, including 216 pathologically-proven renal cancer cases and 216 age- and gender-matched healthy controls, were recruited into this hospital-based case–control study. Genotyping of the APOA1 was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) combined with gel electrophoresis, and then confirmed by direct sequencing.

Results

Patients with renal cancer had a significantly higher frequency of APOA1 -75 AA genotype [odds ratio (OR) = 2.10, 95 % confidence interval (CI) = 1.18, 3.75; P = 0.01] and APOA1 -75 A allele (OR =1.40, 95 % CI = 1.05, 1.87; P = 0.02) than controls. When stratifying by the distant metastasis status, patients with distant metastasis had a significantly higher frequency of APOA1 -75 AA genotype genotype (OR =2.20, 95 % CI = 1.04, 4.68; P = 0.04).

Conclusion

This study is, to our knowledge, the first to examine prospectively an increased risk role of APOA1 -75 AA genotype and APOA1 -75 A allele in renal cancer susceptibility.

Cigarette smoking and other risk factors for kidney cancer death in a Japanese population: Japan Collaborative Cohort Study for evaluation of cancer risk (JACC study)

BACKGROUND

Cigarette smoking is the largest single recognized cause of human cancers. In Western countries, many epidemiologists have reported risk factors for kidney cancer including smoking. However, little is known about the Japanese population.

MATERIALS AND METHODS

We evaluated the association of smoking with the risk of kidney cancer death in the Japan Collaborative Cohort (JACC) Study. Participants included 46,395 males and 64,190 females. The Cox proportional hazards model was used to determine age-and-sex adjusted relative risks.

RESULTS

A total of 62 males and 26 females died from kidney cancer during the follow-up of 707,136 and 1,025,703 person-years, respectively. Heavy smokers (Brinkman index >1200), fondness of fatty foods, hypertension, diabetes mellitus (DM), and obesity were suggested to increase the risk of renal cell carcinoma while walking was suggested to decrease the risk. Even after controlling for age, sex, alcohol drinking and DM, heavy smoking significantly increased the risk.

CONCLUSIONS

The present study suggests that six factors including smoking may increase and/or reduce the risk of kidney cancer in the Japanese population. Because of the small number of outcomes, however, we did not evaluate these factors after adjusting for all possible confounding factors. Further studies may be needed to confirm the findings in this study.

External validation of a pre-operative prognostic nomogram for renal cell carcinoma in two patient populations: a retrospective cohort study

The aim of this study was to establish the discriminating accuracy of Kanao's pre-operative nomogram for renal cell carcinoma in predicting cause-specific survival among representative patients who underwent nephrectomy. Patients originated from two centers: Chiba University Hospital (n= 151) and Chiba Cancer Center (n = 91). We validated the predictive accuracy, which was assessed using Harrell's concordance-index. The concordance-index values were 0.692 and 0.834 for Chiba University Hospital and Chiba Cancer Center, respectively, although it was 0.822 for the combined data sets. Results of external validation were different at each cohort. We constructed calibration plots of Kanao's nomogram and confirmed the tendency at each institution. Inconsistency of results among two centers makes it difficult to reach a valid conclusion. Therefore, the predictive accuracy of Kanao's nomogram was not settled. Clinicians need to confirm the predictive accuracy of Kanao's nomogram and construct calibration plots when applying this nomogram to different patient populations.

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.

Risk factors for renal cell cancer in a Japanese population

The incidence of renal cell cancer has been increasing worldwide. Although the incidence of renal cell cancer in Japan is lower than the rates in the other industrialized countries, there is no doubt that it is increasing. In this paper, we would like to introduce the result of our studies, which evaluate the risk factors for renal cell cancer in Japan. Hypertension, diabetes mellitus, kidney diseases, fondness for fatty food and black tea showed an increased risk of renal cell carcinoma while an intake of starchy roots such as taro, sweet potato and potato reduced the risk of renal cell carcinoma. In Japan, however, drinking black tea may be a surrogate for westernized dietary habits while eating starchy roots may be a surrogate for traditional Japanese dietary habits. Further studies may be needed to evaluate risk factors for renal cell cancer because the number of renal cancer cases was small in our studies in spite of a large population-based cohort study.

Identification of Toll-like receptor 3 as a potential therapeutic target in clear cell renal cell carcinoma

PURPOSE

Renal cell carcinoma (RCC) is one of the most drug-refractory cancers. The aim of this study is to discover a novel therapeutic target molecule for clear cell RCC (CCRCC), which accounts for the majority of RCC.

EXPERIMENTAL DESIGN

Gene expression profiles of 27 CCRCCs and 9 normal kidney tissues as well as 15 various adult normal tissues were examined by Affymetrix U133 Plus 2.0 arrays. Among the 34 genes specifically up-regulated in CCRCC, overexpression of Toll-like receptor 3 (TLR3) mRNA and its protein was validated by quantitative reverse transcription-PCR, immunoblot, and immunohistochemistry. The effects of TLR3 signaling on in vitro cell growth were examined.

RESULTS

TLR3 gene was highly expressed in CCRCC, with only limited expression in a panel of normal tissues. On immunohistochemical analysis using a monoclonal antibody against TLR3, overexpression of TLR3 was observed in 139 of 189 (73.5%) cases of CCRCC as well as in lung metastatic CCRCC (6 of 8), whereas TLR3 expression was entirely absent in chromophobe RCC (0 of 8). Polyinosinic-polycytidilic acid, a TLR3 ligand, exerted a growth-inhibitory effect against RCC cells in a TLR3-dependent manner. Moreover, a combination of polyinosinic-polycytidilic acid and IFNalpha exerted a synergistic growth-inhibitory effect against Caki-1 RCC cells.

CONCLUSIONS

This is the first report that TLR3 is overexpressed in CCRCC. These observations suggest that TLR3 pathway may represent a novel therapeutic target in CCRCC.

Overexpression of the myc target gene Mina53 in advanced renal cell carcinoma

The myc target gene Mina53 was reported to be overexpressed in esophageal cancer with a poor prognosis. The purpose of the present study was to examined Mina53 expression and its relationship to clinicopathological parameters in human renal cell carcinoma (RCC). Mina53 and Ki-67 expression was examined on immunohistochemistry for 64 surgically resected RCC and non-cancerous tissue. In addition, the relationship between Mina53 expression and clinicopathological prognostic factors of RCC such as age, stage, microvenous invasion (MVI), histological subtype, Ki-67 labeling index (LI), and prognosis, was examined. Mina53 was expressed in the nuclei of tumor cells and tubular nuclei of normal renal tissue. The expression level of Mina53 was significantly higher in patients with poor prognostic factors (stage IV, MVI-positive, and sarcomatoid RCC, and high Ki-67 LI). The prognosis of high Mina53-expressing tumors was significantly poorer than that of non-Mina53-high tumors (P < 0.0001). In conclusion, Mina53 is overexpressed in RCC tissue from patients with poor prognostic factors, suggesting that Mina53 overexpression is one of the factors for poor prognosis in RCC.

Prevalence of renal cell carcinoma: a nation-wide survey in Japan, 2002

OBJECTIVE

To investigate the incidence of renal cell carcinoma, classified by sex, age group and region in Japan, following a 5-year interval after a previous survey performed in 1997.

METHODS

The survey was conducted between the beginning of January 2002 and the end of December 2002. A total of 1288 institutions in all 47 prefectures throughout Japan were requested to register cases.

RESULTS

There were 7405 persons with renal cell carcinoma, consisting of 5063 males and 2342 females. Crude incidence rates were 8.2 and 3.6 per 100 000 population for men and women, respectively. Incidence rates in the Hokkaido region were highest followed by the Shikoku region.

CONCLUSIONS

Despite incidence of renal cell carcinoma increasing to 7405 from the 6358 persons in 1997, statistical data reported by the Ministry of Health, Labor and Welfare indicate that rising age-adjusted death rate for this tumor reached a ceiling in the past decade. Early detection may have contributed to this current trend; however, further epidemiological research is required to fully elucidate this.

STAT3Polymorphism Predicts Interferon-Alfa Response in Patients With Metastatic Renal Cell Carcinoma

Purpose

To clarify the effect of genetic polymorphisms on the response to interferon alfa (IFN-α) for metastatic renal cell carcinoma (MRCC), and to find a reliable molecular marker to select those patients with MRCC who would benefit from IFN-α immunotherapy.

Patients and Methods

We carried out an association study in which 463 single nucleotide polymorphisms (SNPs) in 33 candidate genes were genotyped in 75 Japanese patients who had received IFN-α for MRCC.

Results

After adjusting for lung metastasis, stepwise logistic regression analysis revealed that the SNPs in signal transducer and activator 3 (STAT3) were most significantly associated with better response to IFN-α. Linkage disequilibrium mapping revealed that the SNP in the 5′ region of STAT3, rs4796793, was the most significant predictor of IFN-α response (odds ratio [OR] = 2.73; 95% CI, 1.38 to 5.78). The highest OR was shown in the CC genotype at rs4796793 compared to the GG + GC genotypes (OR = 8.38, 95% CI, 1.63 to 42.96). Genotype-dependent expressions of STAT3 in B lymphocyte cell lines and the enhanced growth inhibitory effects of IFN-α by STAT3 suppression in an RCC cell line supported the results of the present association study.

Conclusion

The present study suggested that the STAT3 polymorphism is a useful diagnostic marker to predict the response to IFN-α therapy in patients with MRCC. An efficient response marker for IFN-α needs to be utilized to establish individual optimal treatment strategies, even when newer drug therapies are used as first line treatments for MRCC.

ECOG performance status 0 or 1 and symptom classification do not improve the ability to predict renal cell carcinoma-specific survival

OBJECTIVES

We tested and compared the improvement in prognostic ability related to the consideration of either ECOG performance status (ECOGPS) and/or symptom classification (S-CLASS) in renal cell carcinoma specific mortality (RCC-SM) predictions.

METHODS

Univariate and multivariate Cox regression analyses targeted RCC-SM in 2570 RCC patients treated with either partial or radical nephrectomy. The increment in predictive accuracy related to the addition of either ECOGPS, S-CLASS or both was quantified using Harrell's concordance index.

RESULTS

Follow-up ranged from 0.1 to 23 years (median 3.2) and 610 patients (23.7%) died of RCC. In multivariable analyses, ECOGPS and S-CLASS represented independent predictors of RCC-SM. The addition of ECOGPS to established RCC-SM predictors increased the predictive accuracy by 0.3% (p=0.8) versus 0.6% (p=0.5) for S-CLASS versus 0.6% (p=0.5) for both.

CONCLUSIONS

Neither ECOGPS nor S-CLASS improves the ability to predict RCC-SM. Therefore, these variables may be safely omitted when RCC-SM risk is quantified.

Radiofrequency ablation combined with renal arterial embolization for the treatment of unresectable renal cell carcinoma larger than 3.5 cm: initial experience

The purpose of the study was to evaluate the feasibility, safety, and therapeutic effects of the combination of renal arterial embolization and radiofrequency (RF) ablation to reinforce the anticancer effect on renal cell carcinomas (RCCs) measuring 3.5 cm or larger. This study was undertaken to evaluate this combined therapy on large RCCs-based tumor geometry. Eleven patients with 12 RCCs 3.5 cm or larger in diameter (3.5-9.0 cm) underwent combined therapy. Two were exophytic tumors, and the remaining 10 tumors had components extending into the renal sinus fat. Tumor vessels were selectively embolized in nine patients and the renal artery was completely embolized in two patients with polyvinyl alcohol or ethanol mixed with iodized oil. RF ablation was percutaneously done under the computed tomographic (CT)-fluoroscopic guidance. Response to treatment was evaluated by dynamic contrast-enhanced CT and magnetic resonance (MR) imaging. Tumor enhancement was eliminated after a single RF session in nine tumors (75%), after two sessions in two tumors (17%), and after four sessions in one tumor (8%). Both exophytic tumors (100%) and 7 of 10 tumors having components in the renal sinus fat (70%) were completely ablated with a single RF session. All tumors remained controlled during a mean follow-up period of 13 months and showed significant reduction in tumor sizes (5.2 +/- 1.7 cm to 3.6 +/- 1.4 cm, p < 0.001). A delayed abscess developed in the ablated lesion in a patient, which was percutaneously drainaged. Combined therapy as described in this report is a feasible, relatively safe, and promising treatment method for large RCCs regardless of tumor geometry.

Renal cell carcinoma in dialysis patients: A single center experience

AIM

Renal cell carcinoma (RCC) is a life-threatening complication of end-stage renal disease with an unclear pathogenesis. We evaluated RCC developing in patients undergoing dialysis.

METHODS

In 2624 patients undergoing hemodialysis or continuous ambulatory peritoneal dialysis at our hospital between July 1993 and March 2004, we performed annual screening for RCC using abdominal computed tomography and ultrasonography. Patients diagnosed with RCC underwent radical nephrectomy as well as clinical and pathologic evaluation.

RESULTS

RCC was detected in 44 patients (1.68%; 31 males and 13 females). The age of RCC patients was 55.5 +/- 11.1 years. Dialysis duration before RCC diagnosis was 11.2 +/- 7.2 years. Most RCC were early stage and low stage by TNM classification, 43 patients had N0M0 RCC, whereas one had N1M0. Tumor size was 2.9 +/- 1.9 cm. The predominant histological type of RCC was common or conventional cell-type carcinoma (clear cell carcinoma and granular cell carcinoma). Of patients, 5(11.4%) had bilateral RCC, and satellite tumor lesions in RCC were detected in 13 (29.5%). In 36 patients (81.8%) RCC was accompanied by acquired cystic disease of the kidney. These patients had longer dialysis durations (P = 0.01) and smaller tumors (P = 0.048). RCC metastasized postoperatively in 4 patients (9.1%), while one (2.3%) died of cancer.

CONCLUSIONS

Our dialysis patients showed a higher incidence of RCC than the general population. Prognosis was favorable because tumors were detected by screening when they were small. Therefore, periodical screening for RCC seems very important in dialysis patients.

Renal cell and transitional cell carcinoma in a Japanese population undergoing maintenance dialysis

PURPOSE

We verified differences in the incidence, clinical characteristics and outcomes between patients on chronic dialysis for end stage renal disease with renal cell carcinoma (RCC) and those with transitional cell carcinoma (TCC).

MATERIALS AND METHODS

Data regarding RCC and TCC were reviewed in the medical records of 6,201 patients with end stage renal disease who underwent chronic dialysis between January 1990 and June 2003 in our 38 affiliated dialysis centers, and data were compared with those reported in Australia and New Zealand.

RESULTS

Among the patients RCC developed in 38 (0.61%) and TCC developed in 16 (0.26%) during maintenance dialysis. The primary renal disease was chronic glomerulonephritis in patients with RCC (68.4%) and diabetic nephropathy in patients with TCC (43.8%, p = 0.002). Mean patient age at initiation of dialysis was 45 years for those with RCC and 63 for those with TCC (p < 0.001). Mean interval from dialysis induction to tumor diagnosis was 143 months for patients with RCC and 54 months for patients with TCC (p < 0.001). Of 38 RCCs 23 (60.5%) were incidentally detected by regular abdominal imaging examinations while painless gross hematuria was the cardinal symptom in 13 (81.2%) of 16 TCCs. Overall and cancer specific survivals after tumor diagnosis were significantly superior in patients with RCC compared to those with TCC (p = 0.0001 and p = 0.0003, respectively), and the cancer specific 5-year survival was 88.9% for RCC and 29.5% for TCC. In both cancers tumor stage significantly increased the risk of cancer specific death. Compared with patients from Australia and New Zealand, the incidence of RCC was higher and that of TCC was lower in our patients (p <0.001).

CONCLUSIONS

In the Japanese population on dialysis RCC is more common than TCC. Since long-term dialysis is a risk factor for RCC, regular imaging examinations may have contributed to the favorable outcome of our patients on dialysis with RCC. In contrast, the unfavorable outcome of TCC suggests the need for effective diagnostic measures for early detection of TCC in patients on dialysis.

Phase I study of autologous tumor vaccines transduced with the GM-CSF gene in four patients with stage IV renal cell cancer in Japan: clinical and immunological findings

We produced lethally irradiated retrovirally GM-CSF-transduced autologous renal tumor cell vaccines (GVAX) from six Japanese patients with stage IV renal cell cancer (RCC). Four patients received GVAX ranging from 1.4 x 10(8) to 3.7 x 10(8) cells on 6-17 occasions. Throughout a total of 48 vaccinations, there were no severe adverse events. After vaccination, DTH skin tests became positive to autologous RCC (auto-RCC) in all patients. The vaccination sites showed significant infiltration by CD4(+) T cells, eosinophils, and HLA-DR-positive cells. The kinetic analyses of cellular immune responses using peripheral blood lymphocytes revealed an enhanced proliferative response against auto-RCC in four patients, and cytotoxicity against auto-RCC was augmented in three patients. T cell receptor beta-chain analysis revealed oligoclonal expansion of T cells in the peripheral blood, skin biopsy specimens from DTH sites, and tumors. Western blot analysis demonstrated the induction of a humoral immune response against auto-RCC. Two of the four patients are currently alive 58 and 40 months after the initial vaccination with low-dose interleukin-2. Our results suggest that GVAX substantially enhanced the antitumor cellular and humoral immune responses, which might have contributed to the relatively long survival times of our patients in the present study.

Uncommon metastatic site of renal adenocarcinoma: the oral tongue

Primary tumours metastasizing to the tongue are very unusual and only anecdotal cases have been reported. An exhaustive literature review covering the period from 1970 onwards disclosed only 22 cases of renal adenocarcinoma metastasizing to the tongue. We report the case of an 87-year-old female patient with oral tongue, lung, liver, thyroid gland, pancreas and renal adenocarcinoma metastases. She had undergone contralateral nephrectomy for clear cell carcinoma 10 years before diagnosis of the metastases. The tongue lesion was surgically removed under local anaesthesia. Tongue metastasis of renal adenocarcinoma is usually a manifestation of widespread disease. The prognosis for patients with lingual metastasis of renal adenocarcinoma is poor, the mean interval from diagnosis of tongue metastasis to death being 5.8 months. In our patient, metastatic involvement of the tongue was detected approximately 5 months before death. Treatment of renal adenocarcinoma metastasis to the tongue is usually palliative and aims to provide patient comfort by means of pain relief and prevention of bleeding and infection. Surgical excision is recommended as the primary treatment, with emphasis on preservation of tongue structure and function. Recent data regarding immunotherapy or immunochemotherapy for metastatic renal adenocarcinoma are encouraging.

Histopathological analysis of angiogenic factors in renal cell carcinoma

AIM

The present study was carried out to clarify whether a histopathological analysis of vascular endothelial growth factor (VEGF), transforming growth factor-beta1 (TGF-beta1) and matrix metalloproteinase 2 (MMP-2) can help predict the outcome of renal cell carcinoma (RCC). We examined the expression of VEGF, TGF-beta1 and MMP-2 in a large series of RCC with a long follow-up, based on histopathological factors and survival.

METHODS

Immunostaining for VEGF, TGF-beta1 and MMP-2 was performed on formalin-fixed, paraffin-embedded tissue sections from 84 patients with RCC who underwent nephrectomy at our institution between 1985 to 2000. The microvessel density (MVD) of tumor tissue was measured after it immunohistochemically stained with CD105 (Endoglin) monoclonal antibody.

RESULTS

A significant association was observed in the expression of VEGF and TGF-beta1 regarding the stage (P < 0.01, P < 0.01), nuclear grade (P < 0.01, P < 0.01) and MVD (P < 0.001, P < 0.001), respectively. However, no correlation was found among the results of MMP-2, nuclear grade and MVD. A multivariate analysis demonstrated both the nuclear grade and MVD to be independent prognostic factors.

CONCLUSION

Our results suggested that the expression of both VEGF and/or TGF-beta1 can be useful predictive prognostic factors RCC. In addition, a multivariate analysis demonstrated MVD to be an independent prognostic factor of RCC.

Strain variation in renal carcinogenesis by N-ethyl-N-hydroxyethylnitrosamine in F1 (Wistar-Fischer) rats

The present study was conducted to compare the incidences of renal tumors in Wistar (W), Fischer (F) and F1 rats (WF: female Wistar rats x male Fischer rats; FW: female Fischer rats x male Wistar rats) induced by N-ethyl-N-hydroxyethylnitrosamine (EHEN). Levels of 8-OHdG in renal DNA were also investigated in Wistar and Fischer rats. After 2000 ppm of EHEN was administered orally for 2 weeks, the animals were fed basal diet until week 32. Wistar males and females demonstrated significantly higher sensitivity regarding induction of renal lesions, while both WF and FW rats had similar incidences, generally intermediate between those for the two parent strains. The formation of 8-OHdG was maximal 60-180 min after an intraperitoneal dose of 750 mg/kg to Wistar and Fischer rats, which correlates with the increase tending to the incidence of renal tumors in male and female Wistar and Fischer rats. The results suggest that EHEN induction of renal tumors is related to oxygen radical damage and that the genes in the Wistar strain responsible for the sensitivity are not inherited in a sex-dependent fashion, despite the male being more susceptible.