Epidemiology of Renal Cell Carcinoma

CONTEXT

Despite the improvement in renal cell carcinoma (RCC) diagnosis and management observed during the last 2 decades, RCC remains one of the most lethal urological malignancies. With the expansion of routine imaging for many disorders, an increasing number of patients who harbour RCC are identified incidentally.

OBJECTIVE

To summarise and compare RCC incidence and mortality rates, analyse the magnitude of risk factors, and interpret these epidemiological observations in the context of screening and disease management.

EVIDENCE ACQUISITION

The primary objective of the current review was to retrieve and describe worldwide RCC incidence/mortality rates. Secondly, a narrative literature review about the magnitude of the known risk factors was performed. Finally, data retrieved from the first two steps were elaborated to define the clinical implications for RCC screening.

EVIDENCE SYNTHESIS

RCC incidence and mortality significantly differ among individual countries and world regions. Potential RCC risk factors include behavioural and environmental factors, comorbidities, and analgesics. Smoking, obesity, hypertension, and chronic kidney disease represent established risk factors. Other factors have been associated with an increased RCC risk, although selection biases may be present and controversial results have been reported.

CONCLUSIONS

Incidence of RCC varies worldwide. Within the several RCC risk factors identified, smoking, obesity, and hypertension are most strongly associated with RCC. In individuals at a higher risk of RCC, the cost effectiveness of a screening programme needs to be assessed on a country-specific level due to geographic heterogeneity in incidence and mortality rates, costs, and management implications. Owing to the low rates of RCC, implementation of accurate biomarkers appears to be mandatory.

PATIENT SUMMARY

The probability of harbouring kidney cancer is higher in developed countries and among smokers, obese individuals, and individuals with hypertension.

Alcohol consumption, variability in alcohol dehydrogenase genes and risk of renal cell carcinoma

Alcohol consumption has been associated inversely with renal cell carcinoma (RCC) risk; however, no study has examined effect modification by germline variation in alcohol-metabolizing genes. We investigated whether the association between alcohol intake and RCC risk is modulated by germline variants in alcohol dehydrogenase genes in a large case-control study. Data from 652 RCC cases and 1,366 non-cancer controls were analyzed. Alcohol intake was assessed using a standardized risk factor questionnaire. Three previously genotyped polymorphisms in ADH6 and ADH7 with the TaqMan assay were examined. Odds ratios (ORs) and 95% confidence interval (CI) were calculated using logistic regression, adjusting for covariates. Compared to non-drinkers, ever consumption of alcohol was associated with lower RCC risk (OR = 0.52, 95% CI = 0.42-0.65). Analysis with cubic spline regression curve showed a "J-shaped" relationship between alcohol drinks/day and RCC risk, such that there was no added benefit against RCC for consumption of more than two drinks/day. We observed effect modification by variation in rs1154454 (ADH7) (p_interaction  = 0.007); a per unit increase in alcohol drink/day was associated with 35% lower RCC risk among non-minor allele carriers, a 27% lower risk among those who carry one copy of the minor allele, but no association was observed among those with two copies of the minor allele. These findings indicate that alcohol consumption is associated with lower RCC risk. Consuming more than two drinks a day does not confer additional protection against RCC. The association between alcohol intake and RCC risk appears to be modulated by inter-individual germline variation in alcohol-metabolizing genes.

A prospective study of alcohol consumption and renal cell carcinoma risk

Recent epidemiological studies suggest that alcohol consumption may reduce renal cell carcinoma (RCC) risk, although inconsistent findings have been reported by sex and alcoholic beverage type. To better understand the relationship between alcohol consumption and RCC risk, we conducted an analysis within the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. We followed up participants in the analytic cohort (N = 107,998) through 2010 for incident RCC (N = 408), and computed hazard ratios (HRs) and 95% confidence intervals (CIs) for alcohol intake using Cox regression with adjustment for age, sex, race, study center, hypertension, body mass index, and smoking status. In this study population increasing alcohol consumption was associated with reduced RCC risk compared to non-drinkers (>9.75 g day(-1) : HR, 0.67; 95%CI, 0.50 to 0.89; p trend = 0.002). We observed similar patterns of association for men and women as well as by alcohol beverage type. In analyses stratified by smoking status, the inverse association with consumption was apparent for ever smokers (HR, 0.51; 95%CI, 0.36 to 0.73; p trend<0.0001) but not among never smokers (HR, 1.08; 95%CI, 0.66 to 1.76; P trend = 0.78; p interaction = 0.01). Our study findings offer further support that alcohol consumption is associated with reduced RCC risk, regardless of sex or alcoholic beverage type. The finding of interaction with smoking is novel and requires confirmation.

Alcohol drinking and risk of renal cell carcinoma: results of a meta-analysis

BACKGROUND

The role of alcohol consumption in relation with renal cell carcinoma is still unclear; a few studies have reported a beneficial effect of moderate levels of alcohol consumption, whereas it remains still under debate whether there is a dose-response association.

MATERIALS AND METHODS

Twenty observational studies (4 cohort, 1 pooled and 15 case-control) reporting results on at least three levels of alcohol consumption were selected through a combined search with PubMed and EMBASE of articles published before November 2010. Overall relative risks (RRs) and 95% confidence intervals (CIs) were estimated using random-effects models, and both second-order fractional polynomials and random effect meta-regression models were implemented for the study of dose-risk relation.

RESULTS

The estimated RRs were 0.85 (95% CI: 0.80-0.92) for any alcohol drinking, 0.90 (95% CI: 0.83-0.97) for light drinking (0.01-12.49 g/day), 0.79 (95% CI: 0.71-0.88) for moderate drinking (12.5-49.9 g/day) and 0.89 (95% CI: 0.58-1.39) for heavy drinking (≥50 g/day), respectively.

CONCLUSION

Our meta-analysis supports the hypothesis of a negative effect of moderate alcohol consumption on the risk of renal cell cancer.

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.

Alcohol and kidney damage: a Janus-faced relationship

It has been known for a long time that excessive consumption of alcohol has adverse effects, including adverse impact on kidneys and kidney disease. Recently, observational evidence has been provided that moderate alcohol consumption is associated with less cardiovascular and renal risk. These issues had been summarized and discussed at the recent congress of the European Society for Biomedical Research and Alcoholism in Vienna.

Alcohol intake and risk of renal cell carcinoma: a meta-analysis of published case-control studies

INTRODUCTION

While some studies have indicated that alcohol intake is associated with a decreased risk of renal cell carcinoma, others have not. We conducted a meta-analysis of case-control studies to provide a quantitative assessment of the association between alcohol intake and the risk of renal cell carcinoma.

MATERIAL AND METHODS

We identified studies by a literature search of PubMed and review of references of relevant articles. Both the fixed and random-effects models were used to obtain the summary risk estimates associated with the highest versus the lowest consumption categories depending on the heterogeneity of effects among studies. Dose-response meta-analysis was performed for studies reporting categorical risk estimates for a series of exposure levels.

RESULTS

Fifteen studies were included in this meta-analysis. An inverse association between alcohol consumption and renal cell carcinoma was observed in both the overall alcohol intake group (OR 0.67, 95% CI 0.62-0.73) and subgroups stratified by sex, study design, geographical region, specific beverages and alcohol assessment. The dose-response meta-analysis showed that an increase in alcohol consumption of 12 g of ethanol per day was associated with a 5% statistically significant decreased risk of renal cell cancer.

CONCLUSIONS

High alcohol consumption exhibits a preventive effect for renal cell carcinoma in a dose-response manner. Further efforts should be made to clarify the underlying biological mechanisms.

Alcohol consumption and risk of renal cell cancer: the NIH-AARP diet and health study

Background:

The effect of moderate to heavy drinking (>15 g per day) on renal cell cancer (RCC) risk is unclear.

Method:

The relationship between alcohol consumption and RCC was examined in the NIH-AARP Diet and Health Study (n=49 2187, 1814 cases).

Results:

Compared with >0 to <5 g per day of alcohol consumption, the multivariate relative risk (95% confidence intervals) for 15 to <30 and ⩾30 g per day was, 0.75 (0.63–0.90) and 0.71 (0.59–0.85), respectively, in men and 0.67 (0.42–1.07) and 0.43 (0.22–0.84), respectively, in women.

Conclusion:

Alcohol consumption was inversely associated with RCC in a dose–response manner. The inverse association may be extended to ⩾30 g per day of alcohol intake.

Glycemic index, glycemic load and renal cell carcinoma risk

BACKGROUND

The risk of renal cell carcinoma (RCC) has been related to refined cereals and starchy foods, but the association has not been studied in terms of glycemic index (GI) and glycemic load (GL). To provide information on this issue, we analyzed data from an Italian multicentric case-control study.

MATERIALS AND METHODS

Cases were 767 patients with histologically confirmed, incident RCC. Controls were 1534 subjects admitted to the same hospitals as cases for a wide spectrum of acute, non-neoplastic conditions, unrelated to known risk factors for RCC. Information on dietary habits was derived through a food-frequency questionnaire. Multivariate odds ratios (ORs) and 95% confidence intervals (CIs) for GI and GL intake were adjusted for major relevant covariates.

RESULTS

Compared with the lowest quintile, the ORs for the highest quintile were 1.43 (95% CI 1.05-1.95) for GI and 2.56 (95% CI 1.78-3.70) for GL, with significant trends in risk. Compared with the lowest quintile, the risk of RCC for all subsequent levels of GL was higher in never drinkers than in ever drinkers.

CONCLUSIONS

We found direct relations between dietary levels of GI and GL and RCC risk. This can be related to mechanisms linked to insulin resistance and sensitivity.