Steffen Weikert

The Epidemiology of Renal Cell Carcinoma

CONTEXT Kidney cancer is among the 10 most frequently occurring cancers in Western communities. Globally, about 270 000 cases of kidney cancer are diagnosed yearly and 116 000 people die from the disease. Approximately 90% of all kidney cancers are renal cell carcinomas (RCC). OBJECTIVE The causes of RCC are not completely known. We have reviewed known aetiologic factors. EVIDENCE ACQUISITION The data provided in the current review are based on a thorough review of available original and review articles on RCC epidemiology with a systemic literature search using Medline. EVIDENCE SYNTHESIS Smoking, overweight and obesity, and germline mutations in specific genes are established risk factors for RCC. Hypertension and advanced kidney disease, which makes dialysis necessary, also increase RCC risk. Specific dietary habits and occupational exposure to specific carcinogens are suspected risk factors, but results in the literature are inconclusive. Alcohol consumption seems to have a protective effect for reasons yet unknown. Hardly any information is available for some factors that may have a high a priori role in the causation of RCC, such as salt consumption. CONCLUSIONS Large collaborative studies with uniform data collection seem to be necessary to elucidate a complete list of established risk factors of RCC. This is necessary to make successful prevention possible for a disease that is diagnosed frequently in a stage where curative treatment is not possible anymore.

Body Size and Risk of Prostate Cancer in the European Prospective Investigation into Cancer and Nutrition

Background: Body size has been hypothesized to influence the risk of prostate cancer; however, most epidemiologic studies have relied on body mass index (BMI) to assess adiposity, whereas only a few studies have examined whether body fat distribution predicts prostate cancer. Methods: We examined the association of height, BMI, waist and hip circumference, and waist-hip ratio with prostate cancer risk among 129,502 men without cancer at baseline from 8 countries of the European Prospective Investigation into Cancer and Nutrition (EPIC), using Cox regression, with age as time metric, stratifying by study center and age at recruitment, and adjusting for education, smoking status, alcohol consumption, and physical activity. Results: During a mean follow-up of 8.5 years, 2,446 men developed prostate cancer. Waist circumference and waist-hip ratio were positively associated with risk of advanced disease. The relative risk of advanced prostate cancer was 1.06 (95% confidence interval, 1.01-1.1) per 5-cm-higher waist circumference and 1.21 (95% confidence interval, 1.04-1.39) per 0.1-unit-higher waist-hip ratio. When stratified by BMI, waist circumference and waist-hip ratio were positively related to risk of total, advanced, and high-grade prostate cancer among men with lower but not among those with higher BMI (Pinteraction for waist with BMI, 0.25, 0.02, and 0.05, respectively; Pinteraction for waist-hip ratio with BMI, 0.27, 0.22, and 0.14; respectively). Conclusions: These data suggest that abdominal adiposity may be associated with an increased risk of advanced prostate cancer. This association may be stronger among individuals with lower BMI; however, this finding needs confirmation in future studies. (Cancer Epidemiol Biomarkers Prev 2008;17(11):3252–61)

The tumour-targeting human L19-IL2 immunocytokine: Preclinical safety studies, phase I clinical trial in patients with solid tumours and expansion into patients with advanced renal cell carcinoma

BACKGROUND L19-IL2, a tumour-targeting immunocytokine composed of the recombinant human antibody fragment L19 (specific to the alternatively-spliced EDB domain of fibronectin, a well characterised marker of tumour neo-vasculature) and of human IL2, has demonstrated strong therapeutic activity in animal cancer models. This phase I/II trial was performed to evaluate safety, tolerability, recommended phase II dose (RD) and early signs of activity of L19-IL2. PATIENTS AND METHODS Five cohorts of patients with progressive solid tumours (n=21) received an intravenous infusion of L19-IL2 (from 5 to 30 Mio IU IL2 equivalent dose) on days 1, 3 and 5 every 3 weeks. This treatment cycle was repeated up to six times. In the following expansion phase, patients with metastatic renal cell carcinoma (RCC) (n=12) were treated at the RD of L19-IL2. Clinical data and laboratory findings were analysed for safety, tolerability and activity. RESULTS Preclinical studies in rats and monkeys did not raise any safety concerns. The RD was defined to be 22.5 Mio IU IL2 equivalent. Pharmacokinetics of L19-IL2 was dose proportional over the tested range, with a terminal half-life of 2-3h. Toxicities were manageable and reversible with no treatment-related deaths. We observed stable disease in 17/33 patients (51%) and 15/18 with mRCC (83%) after two cycles. Median progression-free survival of RCC patients in the expansion phase of the study was 8 months (1.5-30.5). CONCLUSIONS L19-IL2 can be safely and repeatedly administered at the RD of 22.5 Mio IU IL2 equivalent in advanced solid tumours. Preliminary evaluation suggests clinical activity of L19-IL2 in patients with mRCC.

Quantitative analysis of survivin mRNA expression in urine and tumor tissue of bladder cancer patients and its potential relevance for disease detection and prognosis

Suppression of apoptosis may favor the onset and progression of cancer. Survivin is an inhibitor of apoptosis that has been suggested as a novel diagnostic/prognostic marker of bladder cancer. In this study, survivin mRNA expression was measured by a sensitive real‐time PCR assay in tumor tissue and urine from bladder cancer patients and assessed for its potential diagnostic and prognostic relevance. Specimens from 53 patients with bladder transitional cell carcinoma (TCC) were analyzed, the controls being normal urothelial tissues (n = 14) and urine from benign disease patients (n = 22) and healthy individuals (n = 14). Survivin transcripts were commonly detected in tumor tissues, but not in normal urothelium, and increasing mRNA levels correlate with progressing pathologic stage (p = 0.001) and grade categories (p < 0.004). Higher levels of expression were associated with a reduced time to recurrence in noninvasive TCCs (p = 0.027, log‐rank test) and a trend toward shorter disease‐free survival in muscle‐invasive tumors (p = 0.067). Urinary survivin analysis detects TCC with higher sensitivity (68.6%) and equal specificity (100%) when compared with cytology (31.4% and 97.1%). Our results indicate that tissue levels of survivin mRNA predict disease‐free survival in noninvasive TCC and may have a role in bladder cancer progression. When analyzed by RT‐PCR in urine, survivin is a highly specific biomarker for TCC detection.

miRNA Profiling Identifies Candidate miRNAs for Bladder Cancer Diagnosis and Clinical Outcome

Bladder cancer is a common cancer in the Western world. The current prognosticators such as tumor grade, stage, size, and multifocality do not accurately reflect the clinical outcome. It is of clinical interest to identify biomarkers that could improve diagnostic and/or prognostic predictions. The objectives of this study were to identify deregulated miRNAs in bladder cancer samples and evaluate their potential as diagnostic and prognostic biomarkers. We screened 723 miRNAs by microarray and selected a subset of 15 distinctively deregulated miRNAs for further validation by real-time quantitative RT-(q)PCR. Seven miRNAs (miR-20a, miR-106b, miR-130b, miR-141, miR-200a, miR-200a*, and miR-205) were found to be up-regulated and eight miRNAs (miR-100, miR-125b, miR-130a, miR-139-5p, miR-145*, miR-199a-3p, miR-214, and miR-222) were found to be down-regulated in malignant bladder tissue samples compared to healthy tissue. Four miRNAs that have already been described in the literature (miR-141, miR-199a-3p, miR-205, and miR-214) were significantly differentially expressed between nonmuscle-invasive and muscle-invasive bladder cancer. Furthermore, real-time RT-qPCR of all miRNAs provided high overall correct classification (>75%) of bladder cancer diagnosis. Two miRNAs (miR-141 and miR-205) were associated with overall survival time. The verification of tumor-specific miRNA expression profile, together with the observed association of miR-141 and miR-205 expression with overall survival, underline the potential of miRNAs to function as diagnostic and/or prognostic markers of bladder cancer.

Contemporary epidemiology of renal cell carcinoma: perspectives of primary prevention

ObjectiveEpidemiological research of recent years has produced evidence for a role of lifestyle-associated risk factors in the etiology of renal cell carcinoma (RCC), the most common renal tumor. In this review, we give an overview of recent trends in incidence and mortality and summarize the current knowledge on risk factors of RCC.MethodsData on incidence and mortality in the literature were reviewed. Global incidence data were derived from the Globocan database. A literature review of epidemiological studies on risk factors of kidney cancer was performed, with special emphasis on recent studies with high level of evidence, i.e., meta-analyses and prospective cohort studies.ResultsThe incidence of renal malignancies has increased over recent decades in the context of the more widespread use of diagnostic imaging. However, time trends and geographic variations in incidence and mortality may also relate to changes in the prevalence of risk factors. Cigarette smoking, excess body weight and uncontrolled blood pressure are the most important and modifiable risk factors for RCC with a high prevalence in the general population. Moreover, dietary habits associated with a Western lifestyle were proposed as potential risk factors, but no food or food group has consistently been related to RCC risk.ConclusionBased on the current evidence, reductions in the prevalence of cigarette smoking, overweight and hypertension are preventive strategies for RCC. More research is needed to establish the underlying mechanisms linking these risk factors and renal carcinogenesis.

Fruits and vegetables and renal cell carcinoma: Findings from the European Prospective Investigation into Cancer and Nutrition (EPIC)

We examined the association between fruits and vegetables and risk of renal cell carcinoma (RCC) in the European Prospective Investigation into Cancer and Nutrition (EPIC). Dietary intake data and complete follow‐up information on cancer incidence were available for 375,851 participants recruited in EPIC centers of 8 countries. During an average follow‐up of 6.2 years, 306 incident cases of RCC were identified. The associations of consumption of total vegetables, total fruits, combined total fruits and vegetables and specific subtypes of vegetables with RCC risk were analyzed using Cox proportional hazards, stratified by centre and adjusted for potential confounders. No significant associations between fruit and vegetable consumption and RCC risk were observed despite a wide range of intake. The estimated relative risks (95% confidence intervals [CI]) in men and women combined were 0.97 (0.85–1.11) per 40 g increase in vegetable intake, 1.03 (0.97–1.08) per 40 g increase in fruit intake and 1.02 (0.93–1.11) per 80 g increase in fruit and vegetable intake combined. Among the vegetable subtypes, an inverse association was observed for root vegetables (RR per 8 g increase: 0.88; 95% CI: 0.78–0.99). These results suggest that total consumption of fruits and vegetables is not related to risk of RCC, although we cannot exclude the possibility that very low consumption is related to higher risk. The relationship of specific fruit and vegetable subgroups with RCC risk warrant further investigation.

Methylation of tumour suppressor genes APAF-1 and DAPK-1 and in vitro effects of demethylating agents in bladder and kidney cancer

To examine the significance of the methylation level of the p53 target and tumour suppressor genes apoptotic protease activating factor-1 (APAF-1) and death-associated protein kinase-1 (DAPK-1) in 80 microdissected tumour samples from transitional cell carcinoma (TCC) of the bladder and 80 tumour samples from clear-cell renal cell carcinoma (RCC) as well as from non-tumourous bladder and kidney tissue. Growth-inhibitory effects of the demethylating agents 5-Aza-2′-deoxycytidine (5-Aza-CdR) and zebularine were investigated in TCC and RCC cell lines. The methylation frequency of APAF-1 (DAPK-1) was 100% (77%) in TCC and 100% (33%) in RCC. The methylation levels of APAF-1 could differentiate between the individual tumour stages in TCC as well as in RCC. The APAF-1 methylation levels in RCC were significantly higher in tumours larger than 4 cm and in high-grade tumours. The methylation frequencies in normal tissue for APAF-1 (DAPK-1) were 11% (8%) in bladder tissue and 9% (5%) in kidney tissue. The growth-inhibitory effect of the demethylating agents in TCC (RT4, T24) and RCC (A498, ClearCa-5) cell lines resulted in a 17–132% prolongation of the doubling time (DT). In RCC cell lines, zebularine was superior to 5-Aza-CdR in achieving a DT prolongation. Quantitative real time RT-PCR detected a re-expression of mRNA transcripts of APAF-1 or DAPK-1. In conclusion, demethylating agents effectively retard growth of TCC and RCC cell lines. Methylation level analysis of specific genes has the potential for further tumour characterisation in TCC and RCC.

Plasma selenium concentration and prostate cancer risk: results from the European Prospective Investigation into Cancer and Nutrition (EPIC)

BACKGROUND Some evidence indicates that a low selenium intake may be associated with an increased risk of prostate cancer. OBJECTIVE The aim of this study was to investigate the association of plasma selenium concentration with subsequent prostate cancer risk and to examine this association by stage and grade of disease and other factors. DESIGN A nested case-control study was performed among men in the European Prospective Investigation into Cancer and Nutrition (EPIC). The association between plasma selenium concentration and prostate cancer risk was assessed in 959 men with incident prostate cancer and 1059 matched controls. RESULTS Overall, plasma selenium concentration was not associated with prostate cancer risk; the multivariate relative risk for men in the highest fifth of selenium concentration compared with the lowest fifth was 0.96 (95% CI: 0.70, 1.31; P for trend = 0.25). There were no significant differences in the association of plasma selenium with risk when analyzed by stage or grade of disease. Similarly, the association of selenium with risk did not differ by smoking status or by plasma alpha- or gamma-tocopherol concentration. CONCLUSION Plasma selenium concentration was not associated with prostate cancer risk in this large cohort of European men.

Metabolic profiling reveals key metabolic features of renal cell carcinoma

Recent evidence suggests that metabolic changes play a pivotal role in the biology of cancer and in particular renal cell carcinoma (RCC). Here, a global metabolite profiling approach was applied to characterize the metabolite pool of RCC and normal renal tissue. Advanced decision tree models were applied to characterize the metabolic signature of RCC and to explore features of metastasized tumours. The findings were validated in a second independent dataset. Vitamin E derivates and metabolites of glucose, fatty acid, and inositol phosphate metabolism determined the metabolic profile of RCC. α‐tocopherol, hippuric acid, myoinositol, fructose‐1‐phosphate and glucose‐1‐phosphate contributed most to the tumour/normal discrimination and all showed pronounced concentration changes in RCC. The identified metabolic profile was characterized by a low recognition error of only 5% for tumour versus normal samples. Data on metastasized tumours suggested a key role for metabolic pathways involving arachidonic acid, free fatty acids, proline, uracil and the tricarboxylic acid cycle. These results illustrate the potential of mass spectroscopy based metabolomics in conjunction with sophisticated data analysis methods to uncover the metabolic phenotype of cancer. Differentially regulated metabolites, such as vitamin E compounds, hippuric acid and myoinositol, provide leads for the characterization of novel pathways in RCC.