Epidemiology and risk factors for kidney cancer. Nat Rev Urol. 2010;7:245-257. [PMID: 20448658 DOI: 10.1038/nrurol.2010.46]

Kidney Cancer and Diabetes Mellitus: A Population-Based Case-Control Study in Taiwan

Introduction: The purpose of this study was to explore whether diabetes mellitus (DM) correlates with the risk of kidney cancer in Taiwan. Materials and Methods: We designed a population-based case-control study from the Taiwan National Health Insurance Database, which consisted of 116 patients with newly diagnosed kidney cancer as cases and 464 subjects without kidney cancer as controls in 2000 to 2009. Both cases and controls were aged ≥20 years. Baseline comorbidities were compared between kidney cancer cases and controls. Results: Multivariable analysis showed no association was detected between DM and kidney cancer (OR 1.06, 95% CI, 0.58 to 1.94). Hypertension (OR 2.05, 95% CI, 1.23 to 3.42), chronic kidney diseases (OR 2.57, 95% CI, 1.23 to 5.37), cystic kidney diseases (OR 18.6, 95% CI, 1.84 to 187.6) and kidney stones (OR 4.02, 95% CI, 2.43 to 6.66) were significant comorbidities associated with increased risk of kidney cancer. Use of alpha-glucosidase inhibitor was associated with increased risk of kidney cancer (OR 4.31, 95% CI, 1.07 to 17.3). Conclusion: DM does not correlate with the risk of kidney cancer. Hypertension, chronic kidney diseases, cystic kidney diseases, kidney stones and use of alpha-glucosidase inhibitors are associated with kidney cancer. Key words: Chronic kidney disease, Cystic kidney disease, Diabetes mellitus, Hypertension, Kidney cancer, Kidney stone

Integrative genome-wide gene expression profiling of clear cell renal cell carcinoma in Czech Republic and in the United States

Gene expression microarray and next generation sequencing efforts on conventional, clear cell renal cell carcinoma (ccRCC) have been mostly performed in North American and Western European populations, while the highest incidence rates are found in Central/Eastern Europe. We conducted whole-genome expression profiling on 101 pairs of ccRCC tumours and adjacent non-tumour renal tissue from Czech patients recruited within the "K2 Study", using the Illumina HumanHT-12 v4 Expression BeadChips to explore the molecular variations underlying the biological and clinical heterogeneity of this cancer. Differential expression analysis identified 1650 significant probes (fold change ≥2 and false discovery rate <0.05) mapping to 630 up- and 720 down-regulated unique genes. We performed similar statistical analysis on the RNA sequencing data of 65 ccRCC cases from the Cancer Genome Atlas (TCGA) project and identified 60% (402) of the downregulated and 74% (469) of the upregulated genes found in the K2 series. The biological characterization of the significantly deregulated genes demonstrated involvement of downregulated genes in metabolic and catabolic processes, excretion, oxidation reduction, ion transport and response to chemical stimulus, while simultaneously upregulated genes were associated with immune and inflammatory responses, response to hypoxia, stress, wounding, vasculature development and cell activation. Furthermore, genome-wide DNA methylation analysis of 317 TCGA ccRCC/adjacent non-tumour renal tissue pairs indicated that deregulation of approximately 7% of genes could be explained by epigenetic changes. Finally, survival analysis conducted on 89 K2 and 464 TCGA cases identified 8 genes associated with differential prognostic outcomes. In conclusion, a large proportion of ccRCC molecular characteristics were common to the two populations and several may have clinical implications when validated further through large clinical cohorts.

Metabolic factors associated with risk of renal cell carcinoma

Previous studies have shown that obesity and hypertension are associated with increased risk of renal cell carcinoma (RCC), but less is known about the association to other metabolic factors. In the Metabolic Syndrome and Cancer project (Me-Can) data on body mass index (BMI, kg/m2), blood pressure, and circulating levels of glucose, cholesterol, and triglycerides were collected from 560,388 men and women in cohorts from Norway, Austria, and Sweden. By use of Cox proportional hazard models, hazard ratios (HR) were calculated for separate and composite metabolic exposures. During a median follow-up of 10 years, 592 men and 263 women were diagnosed with RCC. Among men, we found an increased risk of RCC for BMI, highest vs. lowest quintile, (HR = 1.51, 95% CI 1.13–2.03), systolic blood pressure, (HR = 3.40, 95% CI 1.91–6.06), diastolic blood pressure, (HR = 3.33, 95% CI 1.85–5.99), glucose, (HR = 3.75, 95% CI 1.46–9.68), triglycerides, (HR = 1.79, 95% CI 1.00–3.21) and a composite score of these metabolic factors, (HR = 2.68, 95% CI 1.75–4.11). Among women we found an increased risk of RCC for BMI, highest vs. lowest quintile, (HR = 2.21, 95% CI 1.32–3.70) and the composite score, (HR = 2.29, 95% CI 1.12–4.68). High levels of the composite score were also associated with risk of death from RCC among both men and women. No multiplicative statistical or biological interactions between metabolic factors on risk of RCC were found. High levels of BMI, blood pressure, glucose and triglycerides among men and high BMI among women were associated with increased risk of RCC.

Energy balance, polymorphisms in the mTOR pathway, and renal cell carcinoma risk

BACKGROUND

The interplay between obesity, physical activity, weight gain, and genetic variants in the mTOR pathway has not been studied in renal cell carcinoma (RCC). We examined the associations between obesity, weight gain, physical activity, and RCC risk. We also analyzed whether genetic variants in the mTOR pathway could modify the association.

METHODS

Incident RCC case subjects and healthy control subjects were recruited from the University of Texas MD Anderson Cancer Center in Houston, Texas. Case subjects and control subjects were frequency matched. Epidemiologic data were collected by in-person interview. One hundred ninety single nucleotide polymorphisms (SNPs) from 22 genes in the mTOR pathway were extracted from previous genome-wide association studies. Logistic regression and regression spline were performed to obtain odds ratios (ORs). All statistical tests were two-sided.

RESULTS

A total of 577 non-Hispanic white case subjects and 593 healthy control subjects were included. Obesity at age 20 years (OR = 1.92, 95% confidence interval [CI] = 1.05 to 3.50; P = .03) and age 40 years (OR = 2.03, 95% CI = 1.38 to 2.98; P < .001) and moderate (OR = 1.46, 95% CI = 1.02 to 2.09; P = .04) and massive weight gain (OR = 1.62, 95% CI = 1.10 to 2.39; P = .01) from age 20 to 40 years were each statistically significantly associated with increased RCC risk. Low physical activity was associated with a 4.08-fold increased risk. Among 190 SNPs in the mTOR pathway, six SNPs located in the AKT3 gene were statistically significantly associated with increased risk, and those with three or more unfavorable genotypes had a 1.72-fold increased risk of RCC.

CONCLUSION

Obesity, weight gain, physical activity, and genetic variants in the mTOR pathway may individually and jointly influence susceptibility to RCC.

Dietary intake of nitrate and nitrite and risk of renal cell carcinoma in the NIH-AARP Diet and Health Study

BACKGROUND

Nitrate and nitrite are present in many foods and are precursors of N-nitroso compounds, known animal carcinogens and potential human carcinogens. We prospectively investigated the association between nitrate and nitrite intake from dietary sources and risk of renal cell carcinoma (RCC) overall and clear cell and papillary histological subtypes in the NIH-AARP Diet and Health Study.

METHODS

Nitrate and nitrite intakes were estimated from a 124-item food frequency questionnaire. Over a mean follow-up of 9 years, we identified 1816 RCC cases (n=498, clear cell; n=115, papillary cell) among 491 841 participants. Cox proportional hazard regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Individuals in the highest quintile of nitrite intake from animal sources compared with those in the lowest quintile, had an increased risk of total RCC and clear cell subtype (HR=1.28, 95% CI, 1.10-1.49 and HR=1.68, 95% CI, 1.25-2.27, respectively). Nitrite from processed meats and other animal sources were associated with increased clear cell adenocarcinoma risk (HR=1.33, 95% CI, 1.01-1.76 and HR=1.78, 95% CI, 1.34-2.36, respectively). We found no association for nitrite intake from plant sources or nitrate intake overall.

CONCLUSION

Our findings suggest that nitrite from animal sources may increase the risk of RCC, particularly clear cell adenocarcinomas.

Racial disparity in renal cell carcinoma patient survival according to demographic and clinical characteristics

BACKGROUND

Patients with renal cell carcinoma (RCC) who are black tend to have poorer prognosis than similar patients who are white. This study examined whether the racial disparity in RCC patient survival varies by demographic and clinical characteristics.

METHODS

Nearly 40,000 patients (4359 black and 34,991 white) diagnosed with invasive RCC from 1992 to 2007 were identified from 12 registries in the National Cancer Institute Surveillance, Epidemiology, and End Results program, covering approximately 14% of the US population. Relative survival rates through 2008 were computed using the actuarial method.

RESULTS

Proportionally more blacks than whites were diagnosed with RCC under age 50 and with localized cancer. Overall, the 5-year relative survival rates were 72.6% (95% confidence interval 72.0%-73.2%) for white and 68.0% (66.2%-69.8%) for black patients. Survival was higher among women than men and among younger than older patients. Survival decreased with advancing tumor stage and, within each stage, decreased with increasing tumor size. Patients with clear cell RCC, a more common form among whites, had poorer prognosis than patients with papillary or chromophobe subtypes, which are more common among blacks. Survival for patients who received no surgical treatment (10.5% of white patients and 14.5% of black patients) was substantially lower than for patients treated with nephrectomy, with similar survival among whites and blacks. In all other demographic and clinical subgroups of patients, whites consistently had a survival advantage over blacks.

CONCLUSIONS

Patients with RCC who are white consistently have a survival advantage over those RCC patients who are black, regardless of age, sex, tumor stage or size, histological subtype, or surgical treatment.

The CASP8 -652 6N insertion/deletion promoter polymorphism is associated with renal cell carcinoma risk and metastasis

PURPOSE

Caspase-8 is a key regulator of apoptosis. Its cancer cell antigen induced cell death activity is strongly impacted by the insertion/deletion promoter polymorphism CASP8 -652 6N ins/del (rs3834129). We studied the association of this polymorphism with renal cell carcinoma risk and pathology.

MATERIALS AND METHODS

In this hospital based case-control study 500 Austrian patients were genotyped, including 250 with renal cell carcinoma, and 250 age and gender matched healthy controls. Polymerase chain reaction amplified genomic DNA was evaluated by restriction fragment length polymorphism analysis and automatic sequencing. We assessed associations with renal cell carcinoma risk and pathological factors, and performed a meta-analysis of the literature.

RESULTS

The CASP8 -652 6N ins/del polymorphism was significantly linked to renal cell carcinoma (chi-square for trend = 9.50, p = 0.002). Compared with ins/ins, del/del was associated with a 57% decreased risk of the disease (OR 0.43, 95% CI 0.26-0.73, p = 0.002). Furthermore, del/del was associated with a lower risk of distant metastases (p <0.05) but not with T stage, N stage or grade. On meta-analysis the CASP8 -652 6N ins/del polymorphism was associated with renal cell carcinoma risk (p <0.001).

CONCLUSIONS

The del/del genotype of the CASP8 -652 6N ins/del promoter polymorphism decreases the overall risk of renal cell carcinoma. It may be associated with a decreased risk of metastasis. Larger studies are warranted to validate our findings.

Identification of PCAG1 as a novel prostate cancer-associated gene

The aim of the present study was to identify a new prostate cancer‑associated gene and analyze its expression pattern. Comprehensive expression analysis of expressed sequence tags (ESTs) and microarray data and serial analysis of gene expression (SAGE) were conducted to screen in silico for candidate prostate cancer‑associated genes. Reverse transcription (RT)-PCR was performed to validate prostate cancer specificity. Prostate cancer‑associated gene 1 (PCAG1) was identified. The expression of PCAG1 mRNA and protein was evaluated in common human normal tissues, common malignant tumors, prostate adenocarcinoma and paired adjacent normal prostate tissues. An immunofluorescence assay was conducted to determine the subcellular location of PCAG1. PCAG1 mRNA was absent in the 15 pooled normal tissues (including normal prostate tissue) but registered at low levels in the spleen tissue (+). By contrast, PCAG1 mRNA was significantly higher than in the adjacent normal tissues in each of the 14 cases of prostate cancer, with ~50% scoring a high degree of expression (+++). Of the 32 types of normal tissues, 29 (including normal prostate tissue) demonstrated negative PCAG1 protein staining while the remaining tissues of the adrenal gland, parathyroid gland and liver expressed low levels. While 18/20 cases of prostate adenocarcinoma showed positive expression results, PCAG1 protein expression in the remaining types of cancer was scarce when present at all; only 41/380 other cancer cases demonstrated positive results at a low level. The most substantial PCAG1-positive expression results were identified by cytoplasmic staining in 36/38 prostate adenocarcinoma cases, with 10 cases showing high expression levels, 20 showing medium levels and 6 showing low levels. In the paired adjacent normal prostate tissues, only 3/38 cases showed low level positive staining, while 35/38 cases were negative. Immunofluorescent staining of the human prostate cancer PC3 cell line showed positive PCAG1 expression results in the mitochondria. The present study demonstrated that while PCAG1 mRNA was highly expressed in prostate cancer tissues, it was almost absent in all common normal tissues and paired adjacent normal prostate tissues. Furthermore, PCAG1 protein was also highly expressed in prostate cancer tissues, while few common normal tissues, other common malignant tumors and paired adjacent normal prostate tissues had even low levels of expression. Clarification of the function and transcriptional mechanism of PCAG1 may aid the elucidation of the mechanisms of carcinogenesis and progression of prostate cancer. The unique expression pattern of PCAG1 suggests its potential in certain clinical applications.

The association between chronic renal failure and renal cell carcinoma may differ between black and white Americans

PURPOSE

In the United States, renal cell carcinoma (RCC) incidence is higher among blacks than among whites. Risk of RCC is elevated among end-stage renal disease patients, although no studies have looked at differences by race in the relationship between chronic renal failure and RCC.

METHODS

We investigated RCC risk in relation to chronic renal failure in a population-based case-control study of blacks and whites in Chicago and Detroit. Data, including information on kidney disease, were collected from interviews with 1,217 RCC cases (361 blacks, 856 whites) and 1,235 controls (523 blacks, 712 whites). Odds ratios (OR) and 95 % confidence intervals (CI) were estimated using unconditional logistic regression.

RESULTS

Risk of RCC was increased in relation to chronic renal failure (OR 4.7, 95 % CI 2.2-10.1) and dialysis (OR 18.0, 95 % CI 3.6-91). The association remained after defining exposure as those who had chronic renal failure ≥10 years prior to RCC diagnosis. Chronic renal failure was more strongly associated with RCC among blacks than among whites (OR 8.7, 95 % CI 3.3-22.9 and 2.0, 0.7-5.6, respectively; p (interaction) = 0.03) and among those without a history of diabetes relative to diabetic subjects (OR 8.3, 95 % CI 3.1-22.7 and 1.9, 0.6-5.9, respectively; p (interaction) = 0.03).

CONCLUSIONS

These results suggest that chronic renal failure is a strong risk factor for RCC, particularly among black and non-diabetic subjects. Our findings of differences in risk estimates by race, to our knowledge the first such report, require replication.

A functional insertion/deletion polymorphism (-94 ins/del ATTG) in the promoter region of the NFKB1 gene is related to the risk of renal cell carcinoma

OBJECTIVE

Activated nuclear factor-ĸB is associated with the pathogenesis of numerous malignancies, including renal cell carcinoma (RCC). This study aimed to clarify the influence of a common insertion/deletion polymorphism (-94 ins/del ATTG, rs28362491) in the NFKB1 promoter on RCC susceptibility.

METHODS

We genotyped the NFKB1 -94 ins/del ATTG promoter polymorphism by the TaqMan method and assessed the association with RCC risk, clinicopathological parameters in a case-control study of 1,027 cases and 1,094 controls.

RESULTS

The genotype frequencies were significantly different between RCC cases and controls (p = 0.046). Compared with individuals carrying the ins/del + del/del genotypes, those with the ins/ins genotype had an increased RCC risk [p = 0.036, adjusted odds ratio (OR) = 1.23, 95% confidence interval (CI) = 1.02-1.48], particularly in the subgroup of younger age (p = 0.005, adjusted OR = 1.42, 95% CI = 1.11-1.83) and never smokers (p = 0.013, adjusted OR = 1.34, 95% CI = 1.07-1.69). Furthermore, the polymorphism was significantly associated with the risk of developing localized stage RCC (p = 0.020, OR = 1.26, 95% CI = 1.04-1.53).

CONCLUSIONS

The functional NFKB1 promoter polymorphism is associated with an increased risk of RCC.

Molecular grading of tumors of the upper urothelial tract using FGFR3 mutation status identifies patients with favorable prognosis

Background

Mutations in FGFR3 have been shown to occur in tumors of the upper urothelial tract and may be indicative of a good prognosis. In bladder tumors, the combination of FGFR3 mutation status and Ki-67 level has been used to define a tumor’s molecular grade and predict survival. Pathological evaluation of upper urothelial tumors is currently the best predictor of prognosis, but suffers from variability in pathological assessments. This study investigated the association with prognosis of FGFR3 mutations alone and in combination with Ki-67 in this patient population.

Methods

Genomic DNA was isolated from tumor samples of 80 patients with upper urothelial cancer. The presence of mutation in FGFR3 was evaluated using real-time polymerase chain reaction. Ki-67 protein expression was determined by immunohistochemistry. Kaplan–Meier survival analysis evaluated the relationship of FGFR3 mutations and Ki-67 levels with survival.

Results

FGFR3 mutations were identified in 40% of tumors and were predominantly associated with noninvasive tumors. Overall survival was higher in patients with FGFR3 mutant tumors (P = 0.02) and in molecular grade 1 tumors as determined by FGFR3 and Ki-67 (P = 0.02).

Conclusion

In this study, we confirm the occurrence of FGFR3 mutations in tumors of the upper urothelial tract and its association with a good prognosis. Both FGFR3 and molecular grading are predictors of overall survival. Molecular grading can help to assess the prognosis of patients with upper urinary tract cancer and may represent a new tool for managing this population of patients.

A possible role for microRNA-141 down-regulation in sunitinib resistant metastatic clear cell renal cell carcinoma through induction of epithelial-to-mesenchymal transition and hypoxia resistance

PURPOSE

We identified microRNA driven mechanisms in clear cell renal cell carcinoma associated with the tumor response to the multitargeted receptor tyrosine kinase inhibitor sunitinib.

MATERIALS AND METHODS

We performed screening genome-wide microRNA real-time quantitative polymerase chain reaction on 20 freshly frozen clear cell renal cell carcinoma tissue samples of patients who received sunitinib as first line targeted therapy. Nine patients with progressive disease within 6 months after initiating therapy were considered poor responders and 11 with at least 1-year progression-free survival were considered good responders. We studied microRNA-141 function in vitro by stable up-regulation of microRNA-141, quantification of target gene expression and cell viability in normoxic and hypoxic conditions. Relative expression in clinical and cell line samples was determined by real-time quantitative polymerase chain reaction. Localization of microRNA-141 and its targets was assessed by microRNA in situ hybridization and immunohistochemistry. Hypoxia induced cytotoxicity was assessed by a luminescence adenosine triphosphate detection assay.

RESULTS

Compared to good responders, microRNA-141 was significantly down-regulated in tumors of poor responders to sunitinib. This seemed spatially linked to epithelial-to-mesenchymal transition in vivo. Reintroduction of microRNA-141 in vitro reversed epithelial-to-mesenchymal transition and decreased cell viability in hypoxic conditions.

CONCLUSIONS

In our study microRNA-141 down-regulation driven epithelial-to-mesenchymal transition in clear cell renal cell carcinoma was linked to an unfavorable response to sunitinib therapy. Reintroduction of microRNA-141 in vitro led to epithelial-to-mesenchymal transition reversal and increased sensibility to a hypoxic environment. Future experiments should be done in vivo to see whether microRNA-141 driven reversal of epithelial-to-mesenchymal transition could affect the efficacy of sunitinib treatment.

A functional variant in the MTOR promoter modulates its expression and is associated with renal cell cancer risk

BACKGROUND

The mTOR signaling pathway plays a crucial role in the carcinogenesis of renal cell cancer (RCC). We sought to investigate the influence of genetic variations in the mTOR pathway-related genes on the risk of RCC.

METHODS

We genotyped 8 potentially functional polymorphisms in AKT1, AKT2, PTEN and MTOR genes using the TaqMan method in a case-control study of 710 RCC patients and 760 cancer-free subjects. Unconditional logistic regression, adjusted for potential confounding factors, was used to assess the risk associations. We then examined the functionality of the important polymorphisms.

RESULTS

Of the 8 polymorphisms, after adjusting for multiple comparisons, we found a significant association between one variant (rs2295080) in the promoter of MTOR and reduced RCC risk (P = 0.005, OR = 0.74, 95%CI = 0.59-0.91, TG/GG vs. TT). Another variant (rs701848) in the 3'UTR region of PTEN was associated with increased RCC risk (P = 0.014, OR = 1.45, 95%CI = 1.08-1.96, CC vs. TT); however, the association was not significant after adjusting for multiple comparisons. Furthermore, we observed lower MTOR mRNA levels in the presence of the rs2295080G allele in normal renal tissues. The luciferase reporter assay showed that the rs2295080G allele significantly decreased luciferase activity. No other significant association between the selected polymorphisms and RCC risk was observed.

CONCLUSIONS

Our results suggest that the functional MTOR promoter rs2295080 variant affects RCC susceptibility by modulating the endogenous MTOR expression level. The risk effects and the functional impact of the MTOR rs2295080 variant need further validation.

Common variation at 2q22.3 (ZEB2) influences the risk of renal cancer

Genome-wide association studies (GWASs) of renal cell cancer (RCC) have identified four susceptibility loci thus far. To identify an additional RCC common susceptibility locus, we conducted a GWAS and performed a meta-analysis with published GWASs (totalling 2215 cases and 8566 controls of European background) and followed up the most significant association signals [nine single nucleotide polymorphisms (SNPs) in eight genomic regions] in 3739 cases and 8786 controls. A combined analysis identified a novel susceptibility locus mapping to 2q22.3 marked by rs12105918 (P = 1.80 × 10(-8); odds ratio 1.29, 95% CI: 1.18-1.41). The signal localizes to intron 2 of the ZEB2 gene (zinc finger E box-binding homeobox 2). Our findings suggest that genetic variation in ZEB2 influences the risk of RCC. This finding provides further insights into the genetic and biological basis of inherited genetic susceptibility to RCC.

Brief smoking cessation intervention: a prospective trial in the urology setting

PURPOSE

Urologists have an important role in the treatment of tobacco related diseases, such as kidney and bladder cancer. Despite this role, urologists receive little training in promoting tobacco cessation. We prospectively evaluated a brief smoking cessation intervention offered by a urologist at an outpatient clinic.

MATERIALS AND METHODS

Between 2009 and 2011 adult smokers from a single institution urology clinic were enrolled in a prospective, brief intervention trial or in usual care as controls. All patients were assessed by the validated Fagerström test for nicotine dependence and the readiness to quit questionnaire. Trial patients received a 5-minute brief smoking cessation intervention. The primary outcome was abstinence at 1 year and the secondary outcome was the number of attempts to quit. Multivariate logistic regression was used to identify factors associated with the quit rate and quit attempts.

RESULTS

A total of 179 patients were enrolled in the study, including 100 in the brief smoking cessation intervention, 41 in the brief smoking cessation intervention plus nicotine replacement therapy and 38 usual care controls. Of the participants 81.0% were 40 years old or older with a mean ± SD 11.26 ± 7.23 pack-year smoking history. Mean readiness to quit and tobacco dependence scores were similar in the 2 arms (p = 0.25 and 0.92, respectively). The 1-year quit rate in the brief smoking cessation intervention group was 12.1% vs 2.6% in the usual care group (OR 4.44, p = 0.163) Adding nicotine replacement therapy increased the quit rate to 19.5% (vs usual care OR 9.91, p = 0.039). Patients who received the brief smoking cessation intervention were significantly more likely to attempt to quit (OR 2.31, p = 0.038). Increased readiness scores were associated with an increased quit rate and increased quit attempts.

CONCLUSIONS

Urologists can successfully implement a brief smoking cessation intervention program. Our study highlights the role of the urologist in providing smoking cessation assistance and the significant impact of brief, simple advice about quitting smoking on the smoker quit rate.

Kidney cancer in Sweden: a decrease in incidence and tumour stage, 1979 - 2001

OBJECTIVE

In the Western world the incidence of renal cell carcinoma (RCC) has been increasing for several decades. In Sweden the incidence has decreased since 1980. This may reflect better health of the population. Another possible explanation could be a decrease in incidentally diagnosed RCC. Since these tumours are smaller, relatively more advanced tumours would then enter the cancer registry. The aim of this study was to compare methods of detection of RCC, tumour characteristics and survival from three periods over a timespan of more than 20 years.

MATERIAL AND METHODS

Adult patients (n = 515) with RCC were identified in a well-defined population-based area with the same incidence of RCC as the rest of Sweden. Patient data from three periods, 1979 - 1981 (A), 1989 - 1991 (B) and 1999 - 2001 (C), were collected for gender, age, tumour side, method of detection, tumour size, tumour type, metastasis, T stage and Fuhrman grade at the time of diagnosis. Using the Swedish Cause-of-Death Register, cause-specific survival was calculated. When available, tissue was reanalysed according to modern standards by an experienced pathologist.

RESULTS

The frequency of ultrasound and computed tomography increased and autopsy and intravenous pyelography decreased with time as the first detection method. There was a significant change towards smaller tumours and less severe stages and grades in more recent periods. Metastatic disease was most common in the first period. The distribution between the different histological tumour types did not change over time. Five-year cause-specific survival increased significantly from 41% to 63%. Subgroup analysis found significantly increased survival for patients with no metastases or with low-grade tumours.

CONCLUSION

The data support a true decrease in the incidence of RCC over time in Sweden with a migration towards lower tumour stages but no change in distribution between the different histological subtypes over time.

Body mass index and renal cell cancer: the influence of race and sex

BACKGROUND

Obesity is a risk factor for renal cell (or renal) cancer. The increasing prevalence of obesity may be contributing to the rising incidence of this cancer over the past several decades. The effects of early-age obesity and change in body mass index (BMI) on renal cancer have been studied less thoroughly, and the influence of race has never been formally investigated.

METHODS

Using data gathered as part of a large case-control study of renal cancer (1214 cases and 1234 controls), we investigated associations with BMI at several time points, as well as with height. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were computed using logistic regression modeling. Race- and sex-stratified analyses were conducted to evaluate subgroup differences.

RESULTS

Obesity (BMI ≥ 30 kg/m) early in adulthood (OR = 1.6 [95% CI = 1.1 to 2.4]) and 5 years before diagnosis (1.6 [1.1 to 2.2]) was associated with renal cancer. The association with early-adult obesity was stronger among whites than blacks (test for interaction, P = 0.006), whereas the association with obesity near diagnosis was marginally stronger in women than men (test for interaction, P = 0.08). The strongest association with renal cancer was observed for obese whites both in early adulthood and before interview (2.6 [1.5 to 4.4]); this association was not present among blacks. Estimates of the annual excess rate of renal cancer (per 100,000 persons) attributed to both overweight and obesity (BMI > 25 kg/m) ranged from 9.9 among black men to 5.6 among white women.

CONCLUSION

Obesity, both early and later in life, is associated with an increased risk of renal cancer. The association with early obesity seems to be stronger among whites than blacks.

Specific Roles of MicroRNAs in Their Interactions with Environmental Factors

MicroRNAs (miRNAs) have emerged as critical regulators of gene expression by modulating numerous target mRNAs expression at posttranscriptional level. Extensive studies have shown that miRNAs are critical in various important biological processes, including cell growth, proliferation, differentiation, development, and apoptosis. In terms of their importance, miRNA dysfunction has been associated with a broad range of diseases. Increased number of studies have shown that miRNAs can functionally interact with a wide spectrum of environmental factors (EFs) including drugs, industrial materials, virus and bacterial pathogens, cigarette smoking, alcohol, nutrition, sleep, exercise, stress, and radiation. More importantly, the interactions between miRNAs and EFs have been shown to play critical roles in determining abnormal phenotypes and diseases. In this paper, we propose an outline of the current knowledge about specific roles of miRNAs in their interactions with various EFs and analyze the literatures detailing miRNAs-EFs interactions in the context of various of diseases.

A genetic variant in pre-miR-27a is associated with a reduced renal cell cancer risk in a Chinese population

BACKGROUND

MicroRNAs (miRNAs) are a class of small non-coding RNAs to regulate cell differentiation, proliferation, development, and apoptosis. The single nucleotide polymorphism (SNP) rs895819 is located at the terminal loop of pre-miR-27a. Here, we aimed to investigate whether SNP rs895819 was associated with the development of renal cell cancer (RCC) in a Chinese population.

METHODS

In this case-control study, we recruited 594 RCC patients and 600 cancer-free controls with frequency matched by age and sex. We genotyped this polymorphism using the TaqMan assay and assessed the effect of this polymorphism on RCC survival. Logistic regression model was used to assess the genetic effects on the development of RCC and interactions between rs895819 polymorphism and risk factors.

RESULTS

Compared with AA homozygote, individuals carrying AG/GG genotypes had a statistically significant reduced susceptibility to RCC (adjusted OR = 0.71, 95% CI = 0.56-0.90). Furthermore, AG/GG genotypes were associated with reduced RCC susceptibility in localized clinical stage (adjusted OR = 0.71, 95% CI = 0.55-0.91), and similar effects were observed in well differentiated and poorly differentiated RCC (adjusted OR = 0.71, 95% CI = 0.55-0.93 for well differentiated, adjusted OR = 0.51, 95% CI = 0.28-0.93 for poorly differentiated). We also observed that rs895819 had multiplicative interactions with age and hypertension. However, the polymorphism did not influence the survival of RCC.

CONCLUSION

Our results suggest that the pre-miR-27a rs895819 polymorphism can predict RCC risk in a Chinese population. Larger population-based prospective studies should be used to validate our findings.

Prediagnostic circulating adipokine concentrations and risk of renal cell carcinoma in male smokers

Despite a well-established link between obesity and renal cell carcinoma (RCC), the mechanism through which obesity acts to increase cancer risk is unclear. Adiponectin, leptin and resistin are adipocyte-secreted peptide hormones that may influence RCC development through their demonstrated effects on inflammation, insulin resistance and cell growth and proliferation. We conducted a nested case-control study to evaluate whether prediagnostic serum adiponectin, leptin and resistin levels are associated with RCC risk. This case-control study (273 cases and 273 controls) was nested within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study cohort of Finnish male smokers. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were estimated using conditional logistic regression models, with analyte levels modeled continuously and categorically (defined using quartiles among controls). High adiponectin levels were significantly associated with reduced RCC risk (Quartile 4 versus Quartile 1: OR = 0.52, 95% CI = 0.30-0.88; P trend = 0.01). This association remained upon additional adjustment for body mass index at blood collection and exclusion of cases diagnosed within the first 2 years of follow-up. In addition, model adjustment for adiponectin resulted in a substantial attenuation of the association between BMI and RCC (OR per 5 kg/m(2) changed from 1.19 to 1.05). No clear associations with RCC were observed for leptin or resistin. Our results suggest that elevated levels of circulating adiponectin are associated with decreased subsequent risk of RCC. These findings provide the strongest evidence to date, suggesting that the association between obesity and RCC is mediated at least in part through the effects of low adiponectin.

[Incidence, prevalence and mortality of kidney cancer in Spain: estimates and projections for the 1998-2022 period]

OBJECTIVE

To estimate kidney cancer incidence and prevalence in Spain, based on mortality and survival data from the period 1998-2007, and to provide projections of incidence, prevalence and mortality until the year 2022.

MATERIAL AND METHODS

All-cause and kidney-cancer mortality rates were obtained from the National Statistics Institute and survival data were obtained from the EUROCARE study. Estimations were carried out using the MIAMOD program. The Joinpoint program was used to quantify the expected annual change in the projections.

RESULTS

An increase in the incidence rate is expected in men from, this going from 11.92 (Adjusted Rate - AR=8.66) per 100,000 inhabitants/year to 15.7 (AR=9.55). Prevalence would increase from 72.84 (AR=51.62) to 94.47 (AR=59.57), and mortality would increase from 5.77 (AR=7.29) to 7.29 (AR=4.56). The incidence rate in women would increase from 5.56 (AR=3.86) to 26.77 (AR=16.4). Prevalence would increase from 24.6 (AR=17.28) to 133.69 (81.37), and for mortality, the expected increase would be from 2.46 (AR=1.54) to 11.65 (AR=6.56) cases per 100.000 inhabitants/year.

CONCLUSION

The projections indicate that kidney cancer in Spain follows an increasing trend in incidence, mortality and prevalence. This needs to be considered in order to plan more effective prevention and treatment measures.

Metabolism of kidney cancer: from the lab to clinical practice

CONTEXT

There is increasing evidence for the role of altered metabolism in the pathogenesis of renal cancer.

OBJECTIVE

This review characterizes the metabolic effects of genes and signaling pathways commonly implicated in renal cancer.

EVIDENCE ACQUISITION

A systematic review of the literature was performed using PubMed. The search strategy included the following terms: renal cancer, metabolism, HIF, VHL.

EVIDENCE SYNTHESIS

Significant progress has been made in the understanding of the metabolic derangements present in renal cancer. These findings have been derived through translational, in vitro, and in vivo studies. To date, the most well-characterized metabolic features of renal cancer are linked to von Hippel-Lindau (VHL) loss. VHL loss and the ensuing increase in the expression of hypoxia-inducible factor affect several metabolic pathways, including glycolysis and oxidative phosphorylation. Collectively, these changes promote a glycolytic metabolic phenotype in renal cancer. In addition, other histologic subtypes of renal cancer are also notable for metabolic derangements that are directly related to the causative genes.

CONCLUSIONS

Current knowledge of the genetics of renal cancer has led to significant understanding of the metabolism of this malignancy. Further studies of the metabolic basis of renal cell carcinoma should provide the foundation for the development of new treatment approaches and development of novel biomarkers.

Prediction of disease-related interactions between microRNAs and environmental factors based on a semi-supervised classifier

Accumulated evidence has shown that microRNAs (miRNAs) can functionally interact with a number of environmental factors (EFs) and their interactions critically affect phenotypes and diseases. Therefore, in-silico inference of disease-related miRNA-EF interactions is becoming crucial not only for the understanding of the mechanisms by which miRNAs and EFs contribute to disease, but also for disease diagnosis, treatment, and prognosis. In this paper, we analyzed the human miRNA-EF interaction data and revealed that miRNAs (EFs) with similar functions tend to interact with similar EFs (miRNAs) in the context of a given disease, which suggests a potential way to expand the current relation space of miRNAs, EFs, and diseases. Based on this observation, we further proposed a semi-supervised classifier based method (miREFScan) to predict novel disease-related interactions between miRNAs and EFs. As a result, the leave-one-out cross validation has shown that miREFScan obtained an AUC of 0.9564, indicating that miREFScan has a reliable performance. Moreover, we applied miREFScan to predict acute promyelocytic leukemia-related miRNA-EF interactions. The result shows that forty-nine of the top 1% predictions have been confirmed by experimental literature. In addition, using miREFScan we predicted and publicly released novel miRNA-EF interactions for 97 human diseases. Finally, we believe that miREFScan would be a useful bioinformatic resource for the research about the relationships among miRNAs, EFs, and human diseases.

Urothelial carcinoma of the upper urinary tract diagnosed via FGFR3 mutation detection in urine: a case report

Background

Upper urinary tract cancer is typically diagnosed with urine cytology and imaging techniques. These assays can be limited by sensitivity, specificity, or technical issues making some diagnoses difficult.

Case presentation

A 73-year old man presented to the clinic with a right renal pelvis filling defect that was detected by a CT-scan performed for unrelated reasons. Urine cytology was negative. Cystoscopy, retrograde pyelogram, and partial ureteroscopy were unable to visualize the lesion resulting in an indeterminate diagnosis. A subsequent CT scan confirmed the renal lesion which appeared to have become larger and was consistent with urothelial carcinoma. A urine based genetic assay was used to test for the presence of urothelial carcinoma. This assay evaluates the presence of mutations in fibroblast growth factor receptor 3 (FGFR3). Mutations in FGFR3 are known to be associated with urothelial carcinoma and have a positive predictive value of 95% when detected in patients with no history of TCC. A mutation in exon 10 (Y375C) of FGFR3 was identified. Nephroureterectomy was performed and the subsequent pathology confirmed urothelial carcinoma. In addition, PCR analysis on isolated tumor tissue indicated the tumor carried the same FGFR3 mutation as that of the DNA isolated from urine, consistent with the tumor being the origin of the mutant DNA.

Conclusion

This study indicates that the FGFR3 urine assay, which was originally developed to monitor bladder cancer, is also a useful tool for diagnosing upper urinary tract cancer in a real-life setting.

LncRNAs expression signatures of renal clear cell carcinoma revealed by microarray

Background

Long noncoding RNAs (lncRNAs) are an important class of pervasive genes involved in a variety of biological functions. They are aberrantly expressed in many types of cancers. In this study, we described lncRNAs profiles in 6 pairs of human renal clear cell carcinoma (RCCC) and the corresponding adjacent nontumorous tissues (NT) by microarray.

Methodology/Principal Findings

With abundant and varied probes accounting 33,045 LncRNAs in our microarray, the number of lncRNAs that expressed at a certain level could be detected is 17157. From the data we found there were thousands of lncRNAs that differentially expressed (≥2 fold-change) in RCCC tissues compared with NT and 916 lncRNAs differentially expressed in five or more of six RCCC samples. Compared with NT, many lncRNAs were significantly up-regulated or down-regulated in RCCC. Our data showed that down-regulated lncRNAs were more common than up-regulated ones. ENST00000456816, X91348, BC029135, NR_024418 were evaluated by qPCR in sixty-three pairs of RCCC and NT samples. The four lncRNAs were aberrantly expressed in RCCC compared with matched histologically normal renal tissues.

Conclusions/Significance

Our study is the first one to determine genome-wide lncRNAs expression patterns in RCCC by microarray. The results displayed that clusters of lncRNAs were aberrantly expressed in RCCC compared with NT samples, which revealed that lncRNAs differentially expressed in tumor tissues and normal tissues may exert a partial or key role in tumor development. Taken together, this study may provide potential targets for future treatment of RCCC and novel insights into cancer biology.

Acute doxorubicin insult in the mouse ovary is cell- and follicle-type dependent

Primary ovarian insufficiency (POI) is one of the many unintended consequences of chemotherapy faced by the growing number of female cancer survivors. While ovarian repercussions of chemotherapy have long been recognized, the acute insult phase and primary sites of damage are not well-studied, hampering efforts to design effective intervention therapies to protect the ovary. Utilizing doxorubicin (DXR) as a model chemotherapy agent, we defined the acute timeline for drug accumulation, induced DNA damage, and subsequent cellular and follicular demise in the mouse ovary. DXR accumulated first in the core ovarian stroma cells, then redistributed outwards into the cortex and follicles in a time-dependent manner, without further increase in total ovarian drug levels after four hours post-injection. Consistent with early drug accumulation and intimate interactions with the blood supply, stroma cell-enriched populations exhibited an earlier DNA damage response (measurable at 2 hours) than granulosa cells (measurable at 4 hours), as quantified by the comet assay. Granulosa cell-enriched populations were more sensitive however, responding with greater levels of DNA damage. The oocyte DNA damage response was delayed, and not measurable above background until 10-12 hours post-DXR injection. By 8 hours post-DXR injection and prior to the oocyte DNA damage response, the number of primary, secondary, and antral follicles exhibiting TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling)-positive granulosa cells plateaued, indicating late-stage apoptosis and suggesting damage to the oocytes is subsequent to somatic cell failure. Primordial follicles accumulate significant DXR by 4 hours post-injection, but do not exhibit TUNEL-positive granulosa cells until 48 hours post-injection, indicating delayed demise. Taken together, the data suggest effective intervention therapies designed to protect the ovary from chemotherapy accumulation and induced insult in the ovary must act almost immediately to prevent acute insult as significant damage was seen in stroma cells within the first two hours.

Polymorphisms in the IL-13 and IL-4R genes are associated with the development of renal cell carcinoma

BACKGROUND

Cytokines are the important modulators that bind to their relevant receptors in response to some stimuli to mediate the homeostasis. It has been suggested that the imbalance of immune system of the host might affect the generation of diseases, including cancers.

PATIENTS AND METHODS

We investigated the association between six functional polymorphisms of IL-4, IL-13, and IL-4R genes and susceptibility to renal cell cancer in a hospital-based study, including 620 renal cell carcinoma (RCC) patients and 623 controls. Logistic regression model was used to assess the genetic effects on the development of RCC.

RESULTS

Overall, individuals with IL-4R Ile50Val CT/TT genotypes had a 0.34-fold significantly decreased RCC risk (CT/TT versus CC), and the T variant allele was associated with a decreased risk of RCC in a dose-response manner (Ptrend=0.009). In addition, we also observed that IL-13 C-1055T and Arg130Gln polymorphisms could decrease the risk of RCC [TT versus

CC/CT

odds ratio=0.36, 95% confidence interval (CI)=0.16-0.78; AA versus GG/GA: 0.66, 0.44-0.97, respectively]. Furthermore, a multiplicative interaction association between the combined IL-4R Ile50Val and IL-13 C-1055T genotypes was observed to decrease the risk of RCC (P=0.036).

CONCLUSION

IL-13 and IL-4R may play an important role in the etiology of RCC.

Non-clear cell renal cell carcinoma: does the mammalian target of rapamycin represent a rational therapeutic target?

Non-clear cell renal cell carcinomas (nccRCCs) comprise a heterogenous and poorly characterized group of tumor types for which few treatments have been approved. Although targeted therapies have become the cornerstones of systemic treatment for metastatic renal cell carcinoma, patients with nccRCC have been excluded from many pivotal clinical trials. As such, robust clinical evidence supporting the use of these agents in patients with nccRCC is lacking. Here, we review the disparate nccRCC subtypes, the criteria for diagnosis, and the prognoses associated with each subtype, in addition to evaluating the potential use of mammalian target of rapamycin (mTOR) inhibitors in treating patients with nccRCC. Both genetic analyses and preclinical research indicate a central role for mTOR in nccRCC; a therapy that targets this ubiquitous regulator of cellular signaling could prove efficacious across various tumor subtypes. Results from recent studies exploring targeted therapies as both monotherapy and combination therapy have provided early indications of efficacy in patients with nccRCC. Exploratory analyses support further research with the mTOR inhibitors everolimus and temsirolimus in patients with nccRCC. Current clinical practice guidelines support the use of mTOR inhibitors in patients with nccRCC; however, these recommendations are based on low levels of evidence. Further results from randomized, controlled clinical trials are needed to determine the optimal choice of therapy for patients with nccRCC. Results from ongoing clinical trials of mTOR inhibitors and other agents in nccRCC, as well as their impact on the nccRCC treatment paradigm, are eagerly awaited.

Characterization of N-diethylnitrosamine-initiated and ferric nitrilotriacetate-promoted renal cell carcinoma experimental model and effect of a tamarind seed extract against acute nephrotoxicity and carcinogenesis

Renal cell carcinoma (RCC), the commonest malignancy in adult kidney, lacks of early signs, resulting often in metastasis at first diagnosis. N-Diethylnitrosamine (DEN)-initiated and ferric nitrilotriacetate (FeNTA)-promoted RCC may be a useful experimental model, but it is not well characterized. In this study, histological alterations and oxidative stress markers were analyzed at different times throughout RCC development, histological subtype was re-evaluated in the light of current classification, and a tamarind seed extract (TSE) effect was examined. Male Wistar rats experimental groups were control, TSE, DEN, DEN+FeNTA, and TSE+DEN+FeNTA. TSE was given 2 weeks before DEN administration (200 mg/kg) and throughout the experiment. Fourteen days after DEN treatment, two FeNTA doses (9 mg Fe/kg) for acute nephrotoxicity study, and increasing FeNTA doses (3-9 mg Fe/kg) twice a week for 16 weeks for carcinogenesis protocol, were administered. In acute study, necrosis and renal failure were observed and TSE ameliorated them. Throughout carcinogenesis protocol, preneoplastic lesions were observed since 1 month of FeNTA treatment, which were more evident at 2 months, when also renal cysts and RCC were already detected. RCC tumors were obtained without changes in renal function, and clear cell histological subtype was identified in all cases. 4-Hydroxy-2-nonenal and 3-nitro-L: -tyrosine levels increased progressively throughout protocol. TSE decreased both oxidative stress markers and, although there was no statistical difference, it delayed RCC progress and decreased its incidence (21 %). This study brings an insight of the time course events in this carcinogenesis model, identifies clear cell subtype and establishes TSE renoprotective effects.

Identifying patients with suspected renal tract cancer in primary care: derivation and validation of an algorithm

BACKGROUND

Earlier diagnosis of renal tract cancer could help improve survival so better tools are needed to help this.

AIM

To derive and validate an algorithm to estimate the absolute risk of renal tract cancer in patients with and without symptoms in primary care.

DESIGN

Cohort study using data from 375 UK QResearch® general practices for development and 189 for validation.

METHOD

Included patients were aged 30-84 years free at baseline of a diagnosis of renal tract cancer (bladder, kidney, ureter, or urethra) and without haematuria, abdominal pain, appetite loss, or weight loss in previous 12 months. The primary outcome was incident diagnosis of renal tract cancer recorded in the next 2 years. Risk factors examined were age, body mass index, smoking, alcohol, deprivation, treated hypertension, renal stones, structural kidney problems, diabetes, previous diagnosis of cancer apart from renal tract cancer, haematuria, abdominal pain, appetite loss, weight loss, diarrhoea, constipation, tiredness, and anaemia. Cox proportional hazards models were used to develop separate risk equations in males and females. Measures of calibration and discrimination assessed performance in the validation cohort.

RESULTS

There were 2878 incident cases of renal tract cancer from 4.1 million person-years in the derivation cohort. Independent predictors in both males and females were age, smoking status, haematuria, abdominal pain, weight loss, and anaemia. A history of prior cancer other than renal tract cancer, and appetite loss were predictors for females only. On validation, the algorithms explained 75% of the variation in females and 76% in males. The receiver operating curve statistics were 0.91 (females) and 0.95 (males). The D statistic was 3.53 (females) and 3.60 (males). The 10% of patients with the highest predicted risks contained 87% of all renal tract cancers diagnosed over the next 2 years.

CONCLUSION

The algorithm has good discrimination and calibration and could potentially be used to identify those at highest risk of renal tract cancer, to facilitate more timely referral and investigation.

Diet-induced obesity alters dendritic cell function in the presence and absence of tumor growth

Obesity is a mounting health concern in the United States and is associated with an increased risk for developing several cancers, including renal cell carcinoma (RCC). Despite this, little is known regarding the impact of obesity on antitumor immunity. Because dendritic cells (DC) are critical regulators of antitumor immunity, we examined the combined effects of obesity and tumor outgrowth on DC function. Using a diet-induced obesity (DIO) model, DC function was evaluated in mice bearing orthotopic RCC and in tumor-free controls. Tumor-free DIO mice had profoundly altered serum cytokine and chemokine profiles, with upregulation of 15 proteins, including IL-1α, IL-17, and LIF. Tumor-free DIO mice had elevated percentages of conventional splenic DC that were impaired in their ability to stimulate naive T cell expansion, although they were phenotypically similar to normal weight (NW) controls. In DIO mice, intrarenal RCC tumor challenge in the absence of therapy led to increased local infiltration by T cell-suppressive DC and accelerated early tumor outgrowth. Following administration of a DC-dependent immunotherapy, established RCC tumors regressed in normal weight mice. The same immunotherapy was ineffective in DIO mice and was characterized by an accumulation of regulatory DC in tumor-bearing kidneys, decreased local infiltration by IFN-γ-producing CD8 T cells, and progressive tumor outgrowth. Our results suggest that the presence of obesity as a comorbidity can impair the efficacy of DC-dependent antitumor immunotherapies.

Environmental and modifiable risk factors in renal cell carcinoma

OBJECTIVES

Prevention of disease requires a firm understanding of the relevant environmental and modifiable risk factors. We present a comprehensive review of these factors in renal cell carcinoma.

MATERIALS AND METHODS

A literature search of the PubMed database was performed to identify clinical studies examining the relationship between environmental and modifiable factors in the development of renal cell carcinoma (terms utilized: kidney cancer; renal cell carcinoma; risk factors; environment; obesity; hypertension; trichloroethylene). An emphasis was placed on more recent studies.

RESULTS

Case control and large cohort studies have examined the relationship of numerous environmental and modifiable factors and the risk of renal cell carcinoma. Of particular note are dose-dependent increases in smokers, the obese, and hypertensive patients.

CONCLUSIONS

Environmental and modifiable risk factors contribute significantly to the risk of sporadic renal cell carcinoma. Emphasis should be placed on smoking cessation and hypertension control. Emerging evidence would suggest that dietary intake and quality impact renal cell carcinoma risk.

Alcohol intake and renal cell cancer risk: a meta-analysis

BACKGROUND

An inverse association between alcoholic beverage intake and risk of renal cell cancer has been suggested in recent studies.

METHODS

We examined the association between alcoholic beverages and renal cell cancer risk in a meta-analysis. We identified relevant studies by searching the database of PubMed, EMBASE, and MEDLINE published through August 2011. We combined the study-specific relative risks (RRs) using a random-effects model.

RESULTS

A total of 20 case-control studies, 3 cohort studies, and 1 pooled analysis of cohort studies were included in the meta-analysis. We observed that alcoholic beverage intake was associated with a lower risk of renal cell cancer in combined analysis of case-control and cohort studies; for total alcoholic beverage intake, combined RRs (95% confidence intervals) comparing top with bottom categories were 0.76 (0.68-0.85) in case-control studies, and 0.71 (0.63-0.78) in cohort studies (P for difference by study design=0.02). The inverse associations were observed for both men and women and for each specific type alcoholic beverage (beer, wine, and liquor). Also, we found that one drink per day of alcoholic beverage conferred the reduction in renal cell cancer risk, but further drinking above that level did not add benefit.

CONCLUSION

The findings from our meta-analysis support the hypothesis that alcoholic beverage intake is inversely associated with a lower risk of renal cell cancer, with moderate consumption conferring the protection and higher consumption conferring no additional benefits.

Acute activation of β2-adrenergic receptor regulates focal adhesions through βArrestin2- and p115RhoGEF protein-mediated activation of RhoA

β(2)-Adrenergic receptors (β(2)ARs) regulate cellular functions through G protein-transduced and βArrestin-transduced signals. β(2)ARs have been shown to regulate cancer cell migration, but the underlying mechanisms are not well understood. Here, we report that β(2)AR regulates formation of focal adhesions, whose dynamic remodeling is critical for directed cell migration. β(2)ARs induce activation of RhoA, which is dependent on βArrestin2 but not G(s). βArrestin2 forms a complex with p115RhoGEF, a guanine nucleotide exchange factor for RhoA that is well known to be activated by G(12/13)-coupled receptors. Our results show that βArrestin2 forms a complex with p115RhoGEF in the cytosol in resting cells. Upon β(2)AR activation, both βArrestin2 and p115RhoGEF translocate to the plasma membrane, with concomitant activation of RhoA and formation of focal adhesions and stress fibers. Activation of RhoA and focal adhesion remodeling may explain, at least in part, the role of β(2)ARs in cell migration. These results suggest that βArrestin2 may serve as a convergence point for non-G(12/13) and non-G(q) protein-coupled receptors to activate RhoA.

Association of Ku70 A-31G polymorphism and risk of renal cell carcinoma in a Chinese population

The DNA repair gene Ku70 plays a key role in the DNA double-strand breaks (DSBs) repair system. Defects in DSBs repair capacity can lead to genomic instability. We hypothesized that the Ku70 A-31G polymorphism (rs132770) was associated with the risk of renal cell carcinoma (RCC). In a hospital-based case-control study of 620 RCC patients and 623 cancer-free controls frequency matched by age and sex, we genotyped the functional polymorphism Ku70 A-31G (rs132770). Thirty-eight normal renal tissue samples with different genotypes were tested to estimate the Ku70 mRNA expression by real-time quantitative reverse transcription. Compared with the GG genotype, the GA and GA/AA genotypes had a significantly decreased risk of RCC [adjusted odds ratio (OR) = 0.62, 95% confidence interval (CI) = 0.44-0.87 for GA, and OR = 0.62, 95% CI = 0.45-0.86 for GA/AA]. The in vivo experiments with normal renal tissues revealed that a statistically significantly higher Ku70 mRNA expression was identified in samples with GA/AA genotypes compared with those with GG genotypes (p = 0.001). These results suggested that the Ku70 A-31G polymorphism is involved in the etiology of RCC and, thus, may be a marker for genetic susceptibility to RCC in the Chinese populations.

Cigarette smoking and renal cell carcinoma risk among black and white Americans: effect modification by hypertension and obesity

BACKGROUND

Incidence of kidney cancer has been increasing over the past three decades, with more rapid increases and higher incidence rates among blacks than whites in the United States. An association between cigarette smoking and renal cell carcinoma (RCC), the most common form of kidney cancer, has been reported for whites, but the association in blacks is less clear.

METHODS

The association between smoking and RCC was examined in 1,217 incident cases and 1,235 population controls frequency-matched on age, race, gender, and study site in the Kidney Cancer Study in Detroit, MI, and Chicago, IL.

RESULTS

In white individuals, increasing duration and number of pack-years of both were associated with increased risk of RCCs after adjusting for age, gender, education, study site, body mass index (BMI) and history of hypertension (P(trend) = 0.0002 and P(trend) = 0.002, respectively). Among black individuals, RCC risk increased with duration of smoking (P(trend) = 0.02) but not other measures. Compared with current smokers, RCC risk decreased with increasing years of smoking cessation among both whites and blacks (P(trend) = 0.01 and 0.02, respectively). When examining risk according to hypertension history, associations between smoking and RCC risk were observed only among individuals who reported never having been diagnosed with hypertension. Similarly, cigarette smoking was associated with increased risk of RCCs among nonobese individuals but not among those with BMI ≥ 30 kg/m(2).

CONCLUSION

Our observation that smoking is associated with RCC only in nonobese individuals and those with no history of hypertension are novel findings.

IMPACT

The complex relationships between RCCs, smoking, hypertension, and obesity require additional confirmation.

The chromosome 2p21 region harbors a complex genetic architecture for association with risk for renal cell carcinoma

In follow-up of a recent genome-wide association study (GWAS) that identified a locus in chromosome 2p21 associated with risk for renal cell carcinoma (RCC), we conducted a fine mapping analysis of a 120 kb region that includes EPAS1. We genotyped 59 tagged common single-nucleotide polymorphisms (SNPs) in 2278 RCC and 3719 controls of European background and observed a novel signal for rs9679290 [P = 5.75 × 10(-8), per-allele odds ratio (OR) = 1.27, 95% confidence interval (CI): 1.17-1.39]. Imputation of common SNPs surrounding rs9679290 using HapMap 3 and 1000 Genomes data yielded two additional signals, rs4953346 (P = 4.09 × 10(-14)) and rs12617313 (P = 7.48 × 10(-12)), both highly correlated with rs9679290 (r(2) > 0.95), but interestingly not correlated with the two SNPs reported in the GWAS: rs11894252 and rs7579899 (r(2) < 0.1 with rs9679290). Genotype analysis of rs12617313 confirmed an association with RCC risk (P = 1.72 × 10(-9), per-allele OR = 1.28, 95% CI: 1.18-1.39) In conclusion, we report that chromosome 2p21 harbors a complex genetic architecture for common RCC risk variants.

Prognostic significance of diabetes mellitus in localized renal cell carcinoma

OBJECTIVE

We investigated whether diabetes mellitus is associated with the cancer-related outcomes in patients with localized clear cell renal cell carcinoma treated with radical or partial nephrectomy.

METHODS

We reviewed data from 950 patients who received radical or partial nephrectomy for localized clear cell renal cell carcinoma from 1988 to 2009. We analyzed potential association of patients' diabetic status and various clinicopathologic features. Univariate and multivariate analyses were performed to identify independent predictors of cancer-specific survival, overall survival and non-cancer-related survival.

RESULTS

Of 950 patients, 108 (11.4%) reported having diabetes mellitus pre-operatively. Patients with and without diabetes mellitus demonstrated no significant differences regarding various clinicopathologic features except for age (P < 0.001), pre-existing hypertension (P < 0.001), pre-existing cardiovascular disease (P < 0.001) and performance status (P = 0.019). In terms of cancer-specific, overall and non-cancer-related survival, the Kaplan-Meier curves showed that non-diabetic patients had superior survival rates than diabetics (P = 0.012, <0.001 and <0.001, respectively). Meanwhile, although diabetes mellitus was shown to be an independent predictor of overall survival (P = 0.022) and non-cancer-related survival (P = 0.034), it was not observed to be a significant predictor of cancer-specific survival (P = 0.234) in multivariate analyses.

CONCLUSIONS

Diabetes mellitus may not be directly associated with disease-specific outcome in patients who receive surgical management for localized renal cell carcinoma. However, since diabetes mellitus was observed to be associated with overall survival in such patients, diabetic patients undergoing surgery for localized renal cell carcinoma should be counseled on the potential impact of diabetes mellitus. Institutional review board (IRB) approval number H-1106-062-366.

Modest improvement in 20 years of kidney cancer care in the Netherlands

AIM

For an evaluation of the progress achieved in the field of kidney cancer care in the Netherlands in the last decades, we described trends in incidence, treatment, mortality and relative survival.

METHODS

All adult patients newly diagnosed with kidney cancer between 1989 and 2009 (N=32,545) were selected from the Netherlands Cancer Registry. Age-standardised incidence and mortality rates were calculated. Follow-up was completed until January 2010. In order to assess trends estimated annual percentages of change (EAPC) were estimated.

RESULTS

The incidence of kidney cancer has been fairly stable between 1989 and 2001 with a European Standardised Rate of approximately 11 per 100,000 person years (PY). Since 2001 the incidence increased to 13 per 100,000 PY in 2009 (EAPC: 2.4%; 95%confidence interval (CI): 1.5 to 3.4%). The mortality rate decreased slightly over time, from 6.2 per 100,000 PY in 1989 to 5.6 in 2010. No changes in treatment were observed, except for the introduction of targeted therapies for stage IV disease, since 2005. The 5-year relative survival improved from 51% in 1989-1994 to 58% in 2005-2009 (EAPC: 0.9%; 95%CI 0.7 to 1.2%). Improvement in survival was especially seen in males, younger age groups and low stages.

CONCLUSIONS

The incidence of kidney cancer has increased slightly, and survival improved modestly, resulting in a decreasing mortality. A positive effect of the introduction of targeted therapies for metastatic kidney cancer was observed in 1-year relative survival. For progress in kidney cancer care, effective prevention strategies and new therapies remain warranted.