Does beer, wine or liquor consumption correlate with the risk of renal cell carcinoma? A dose-response meta-analysis of prospective cohort studies

Effect of smoking, hypertension and lifestyle factors on kidney cancer - perspectives for prevention and screening programmes

Renal cell carcinoma (RCC) incidence has doubled over the past few decades. However, death rates have remained stable as the number of incidental renal mass diagnoses peaked. RCC has been recognized as a European health care issue, but to date, no screening programmes have been introduced. Well-known modifiable risk factors for RCC are smoking, obesity and hypertension. A direct association between cigarette consumption and increased RCC incidence and RCC-related death has been reported, but the underlying mechanistic pathways for this association are still unclear. Obesity is associated with an increased risk of RCC, but interestingly, improved survival outcomes have been reported in obese patients, a phenomenon known as the obesity paradox. Data on the association between other modifiable risk factors such as diet, dyslipidaemia and physical activity with RCC incidence are conflicting, and potential mechanisms underlying these associations remain to be elucidated.

Alcohol consumption and socioeconomic status associated with the risk of kidney cancer in a large Australian cohort study

PURPOSE

Studies have shown an inverse association between alcohol consumption and kidney cancer risk. We postulate that this inverse association may be further influenced by other risk factors.

METHODS

We used an Australian cohort, the 45 and Up Study recruited between 2005-2009 to investigate the association between alcohol consumption, and other potential risk factors and kidney cancer incidence. The median follow up was 5.4 years.

RESULTS

Of the 267 357 participants aged ≥45 years living in New South Wales, 497 were diagnosed with kidney cancer. There was a significant inverse association between alcohol consumption and risk of kidney cancer (p = 0.027), and a significant inverse dose-response relationship (p=0.011). There was significant interaction between alcohol consumption and socioeconomic status (p interaction = 0.001). Participants residing in higher socioeconomic areas (the two most advantaged quintiles) who consumed 8-10 drinks or >10 drinks per week, respectively, had a lower risk of kidney cancer compared to the group who consumed 1-4 drinks per week (HR 0.34, 95% CI 0.15-0.76, HR 0.51, 95% CI 0.31-0.83) with a dose-response trend of HR 0.62 (95% CI 0.42-0.93) per 7 drink increase in weekly alcohol consumption.

CONCLUSION

There could be an inverse association between alcohol consumption and risk in those residents in higher socioeconomic areas.

DATA AVAILABILITY

The data that support the findings of this study are available from the Sax Institute (https://www.saxinstitute.org.au/our-work/45-up-study/).

Epidemiology and Prevention of Renal Cell Carcinoma

With 400,000 diagnosed and 180,000 deaths in 2020, renal cell carcinoma (RCC) accounts for 2.4% of all cancer diagnoses worldwide. The highest disease burden developed countries, primarily in Europe and North America. Incidence is projected to increase in the future as more countries shift to Western lifestyles. Risk factors for RCC include fixed factors such as gender, age, and hereditary diseases, as well as intervening factors such as smoking, obesity, hypertension, diabetes, diet and alcohol, and occupational exposure. Intervening factors in primary prevention, understanding of congenital risk factors and the establishment of early diagnostic tools are important for RCC. This review will discuss RCC epidemiology, risk factors, and biomarkers involved in reducing incidence and improving survival.

Alcohol Consumption: Medical Implications, the Liver and Beyond

Alcohol consumption represents a major factor of morbidity and mortality, with a wide range of adverse medical implications that practically affect every organ system. It is the fifth major cause of deaths in men and women and causes up to 139 million disability-adjusted life years. Solid evidence places the risk as undoubtedly correlated to the length of time and amount of alcohol consumption. While alcohol-related liver disease represents one of the most studied and well-known consequences of alcohol use, the term itself embodies a wide spectrum of progressive disease stages that are responsible for almost half of the liver-related mortality worldwide. We discuss the staged alcohol-related fatty liver, alcohol-related steatohepatitis and, finally, fibrosis and cirrhosis, which ultimately may end up in a hepatocellular carcinoma. Other comorbidities such as acute and chronic pancreatitis; central nervous system; cardiovascular, respiratory and endocrine system; renal disease; urological pathologies; type 2 diabetes mellitus and even infectious diseases are reviewed in their relation to alcohol consumption. This article reviews the impact of alcohol use on different systems and organs, summarizing available evidence regarding its medical implications. It examines current basic and clinical data regarding mechanisms to highlight factors and processes that may be targetable to improve patient outcomes. Although alcohol use is a part of many cultural and social practices, as healthcare providers we must identify populations at high risk of alcohol abuse, educate patients about the potential alcohol-related harm and provide appropriate treatment.

Alcohol and Health Outcomes: An Umbrella Review of Meta-Analyses Base on Prospective Cohort Studies

An umbrella review of meta-analyses was performed to summarize the evidence of associations between alcohol consumption and health outcomes and to assess its credibility. Meta-analyses of prospective cohort studies reporting the associations of alcohol consumption with health outcomes were identified. We recalculated the random-effects summary effect size and 95% confidence interval, heterogeneity, and small-study effect for each meta-analysis and graded the evidence. Fifty-nine publications reporting 224 meta-analyses of prospective cohort studies with 140 unique health outcomes were included, in which there were 49 beneficial associations and 25 harmful associations with nominally statistically significant summary results. But quality of evidence was rated high only for seven beneficial associations (renal cell carcinoma risk, dementia risk, colorectal cancer mortality, and all-cause mortality in patients with hypertension for low alcohol consumption; renal cell carcinoma risk, cardiovascular disease (CVD) risk in patients with hypertension and all-cause mortality in patients with hypertension for moderate consumption) and four harmful associations (cutaneous basal cell carcinoma risk for low alcohol consumption; cutaneous basal cell carcinoma risk and cutaneous squamous cell carcinoma risk for moderate alcohol consumption; hemorrhagic stroke risk for high alcohol consumption). In this umbrella review, only 11 health outcomes (5 in low alcohol consumption, 5 in moderate alcohol consumption and 1 in high alcohol consumption) with statistically significant showed high quality of epidemiologic evidence. More robust and larger prospective studies are needed to verify our results.

The role of diet in renal cell carcinoma incidence: an umbrella review of meta-analyses of observational studies

BACKGROUND

Evidence associating diet with the incidence of renal cell carcinoma (RCC) is inconclusive. We aimed to summarize evidence associating dietary factors with RCC incidence and assess the strength and validity of this evidence.

METHODS

We conducted an umbrella review of systematic reviews or meta-analyses (SRoMAs) that assessed the association between diet and RCC incidence. Through April 2021, PubMed, Web of Science, Embase, The Cochrane Library, Scopus, and WCRF were searched. Two independent reviewers selected studies, extracted data, and appraised the quality of SRoMAs. According to credibility assessment criteria, evidence can be divided into five categories: convincing (class I), highly suggestive (class II), suggestive (class III), weak (class IV), and nonsignificant (class V).

RESULTS

Twenty-nine meta-analyses were obtained after screening. After excluding 7 overlapping meta-analyses, 22 meta-analyses including 502 individual studies and 64 summary hazard ratios for RCC incidence were included: dietary patterns or dietary quality indices (n = 6), foods (n = 13), beverages (n = 4), alcohol (n = 7), macronutrients (n =15), and micronutrients (n =19). No meta-analyses had high methodological quality. Five meta-analyses exhibited small study effects; one meta-analysis showed evidence of excess significance bias. No dietary factors showed convincing or highly suggestive evidence of association with RCC in the overall analysis. Two protective factors had suggestive evidence (vegetables (0.74, 95% confidence interval 0.63 to 0.86) and vitamin C (0.77, 0.66 to 0.90)) in overall analysis. One protective factor had convincing evidence (moderate drinking (0.77, 0.70 to 0.84)) in Europe and North America and one protective factor had highly suggestive evidence (cruciferous vegetables (0.78, 0.70 to 0.86)) in North America.

CONCLUSIONS

Although many meta-analyses have assessed associations between dietary factors and RCC, no high-quality evidence exists (classes I and II) in the overall analysis. Increased intake of vegetables and vitamin C is negatively associated with RCC risk. Moderate drinking might be beneficial for Europeans and North Americans, and cruciferous vegetables might be beneficial to North Americans, but the results should be interpreted with caution. More researches are needed in the future.

TRIAL REGISTRATION

PROSPERO CRD42021246619.

Associations between Low to Moderate Consumption of Alcoholic Beverage Types and Health Outcomes: A Systematic Review

Aims

There is limited research comparing light to moderate wine, beer and spirits consumption and their impact on long-term health. This systematic review aims to investigate the studies published in the past 10 years and qualitatively assess the similarities and differences between the three main beverages, when consumed at a low to moderate level, for their associations with various health outcomes.

Methods

A systematic search was conducted for comparative studies published in English language (2010 to mid-2021) of beverage-specific low to moderate alcohol consumption associated with all-cause mortality, cancer, cardiovascular disease and diabetes mellitus type II.

Results

The search yielded a total of 24 studies (8 meta-analyses; 15 prospective studies and 1 pooled analysis). Overall, most studies showed similar associations of different alcoholic beverages with chronic conditions, including all-cause mortality, many types of cancer, cardiovascular disease and diabetes mellitus type II. Not all data are consistent. Some studies show more beneficial or detrimental effects of wine than other beverage types, whereas other studies show such effects for other beverages.

Conclusion

Moderate consumption of one specific alcoholic beverage (wine, beer or spirits) may not be consistently associated with higher or lower risks for common health outcomes as compared with moderate consumption of any of the other alcoholic beverages.

Comorbidity and frailty assessment in renal cell carcinoma patients

PURPOSE

Renal cell carcinoma (RCC) incidence has considerably increased during the last decades without any real impact on age-standardized mortality. It questions the relevance of aggressive treatments carrying potential side effects. Conservative management should be considered for frail patients. Comorbidity and frailty assessment in RCC patients is paramount before engaging a treatment.

METHODS

Narrative, non-systematic review based on PubMed and EMBASE search with the terms "renal neoplasm", "elderly, frail", "comorbidities", "active surveillance", "metastatic". The selection was restricted to articles written in English.

RESULTS

Comorbidity and frailty assessment go along with the cancer-specific aggressivity and intervention risks assessment. In localized disease, several standardized algorithms offer patient health evaluation to define how suitable the patient would be for curative treatment. The pre-operative American Society of Anesthesiologists and the age-adjusted Charlson's scores are the most widely used. At the metastatic stage, drug combinations based on immunotherapies and targeted therapies improved cancer outcomes at the price of significant toxicities. Frail patients are not always suitable for such strategies. Commonly used scores like the International Metastatic RCC Database Consortium or Memorial Sloan Kettering Cancer Center integrate features to define patients' risk groups, more specifically the Karnofsky Performance Score is an easy way to document the frailty.

CONCLUSIONS

Comorbidity and frailty have to be assessed at any stage of the RCC disease based on a standardized scoring system to define the most suitable treatment strategy ranging from surveillance to aggressive treatment.

A Global Trend Analysis of Kidney Cancer Incidence and Mortality and Their Associations with Smoking, Alcohol Consumption, and Metabolic Syndrome

BACKGROUND

Kidney cancer is a major urological disease globally, with more than 400 000 new cases diagnosed every year.

OBJECTIVE

To investigate incidence and mortality trends for kidney cancer and their associations with modifiable risk factors for kidney cancer.

DESIGN, SETTING, AND PARTICIPANTS

The most up-to-date figures on kidney cancer incidence and mortality were collected from the GLOBOCAN database and the Cancer Incidence in Five Continents (CI5). Data on total alcohol consumption and the prevalence of smoking, overweight, diabetes, and hypertension were extracted from the World Health Organization Global Health Observatory data repository.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Age-standardized rates (ASRs) for incidence and mortality and their correlations with potential risk factors for kidney cancer were investigated. Multivariable linear regression analysis was also conducted. The 10-yr temporal patterns for incidence are presented as the average annual percent change with 95% confidence interval using joinpoint regression analysis.

RESULTS AND LIMITATIONS

Globally, there is wide variation in kidney cancer incidence and mortality. There were positive correlations between rates of smoking, alcohol consumption, and overweight and ASRs of kidney cancer incidence and mortality. Multivariable regression analysis revealed that alcohol consumption and overweight were significant risk factors for kidney cancer incidence, while smoking and alcohol consumption were significant risk factors for kidney cancer mortality. There was an increasing trend for the incidence of kidney cancer globally, with a particularly prominent trend for European countries. Of note, increasing incidence of kidney cancer is evident even for younger individuals aged <50 yr. However, cancer registries vary by country and period and there is a lack of data regarding the severity of risk factors and disease characteristics such as the distribution of histological groups, tumor grading, and staging.

CONCLUSIONS

There is an increasing trend for kidney cancer incidence globally, particularly in European countries and the younger population. Modifiable risk factors for kidney cancer incidence and mortality have been identified. The increasing incidence of kidney cancer among younger individuals is worrying and warrants early action on possible preventive measures.

PATIENT SUMMARY

The incidence of kidney cancer has been increasing globally, particularly in European countries and the younger population. Risk factors include smoking, alcohol consumption, overweight, and hypertension, and these factors are all modifiable.

[Differential health effects of alcoholic beverages: an umbrella review of observational studies.]

BACKGROUND

There is great controversy about whether the consumption of different types of alcoholic beverages has different effects on health. The objective was to carry out an umbrella review of the studies that described the association between the consumption of different types of alcoholic beverages and various health indicators.

METHODS

Search through PubMed (from January 2000 to February 2019) of systematic reviews and meta-analysis that reported quantitative results of the association between the consumption of different types of alcoholic beverages and health effects. 26 studies were identified: 21 related to cancer, three to cardiometabolic diseases, two to neurodegenerative diseases, and one to general mortality.

RESULTS

The results were heterogeneous. The great methodological differences in the estimation of alcohol intake, control of confounding variables, and the evaluation of statistical difference between types of beverages, made it very difficult to conclude whether they cause an unequal effect on health. In general mortality and cardiometabolic diseases, it was suggested that beer and spirits appear to have a greater negative effect than wine, but the differences were not statistically significant. Regarding cancer, in those types where the causal evidence is totally consistent: oropharynx, colorectal and breast (women), the reviews did not show a differentiated effect according to the type of alcoholic beverages. Regarding neurodegenerative diseases, the available information did not allow clear conclusions to be drawn.

CONCLUSIONS

The reviewed evidence does not allow to conclude that the consumption of wine, beer or spirits, has a differential effect on cardiometabolic, cancer or neurodegenerative diseases.

Alcohol consumption, drinking patterns and cancer incidence in an Australian cohort of 226,162 participants aged 45 years and over

BACKGROUND

Although overall alcohol consumption is known to increase the risk of a number of cancers internationally, evidence for Australia and evidence regarding the pattern of drinking and cancer risk is limited.

METHODS

Adjusted hazard ratios (HR) and 95% confidence intervals (CI) for cancer risk in relation to overall alcohol consumption (drinks/week) and pattern of drinking were calculated using Cox proportional hazard regressions for 226,162 participants aged ≥45 years (2006-2009) in the 45 and Up Study, an Australian prospective cohort study. Incident primary cancer cases were ascertained by linkage to the New South Wales Cancer Registry to 2013 by the Centre for Health Record Linkage.

RESULTS

Over a median of 5.4 years, 17,332 cancers were diagnosed. Increasing levels of alcohol intake were associated with increased risk of cancers of the upper aerodigestive tract (1.19; 1.10-1.29), mouth and pharynx (1.18; 1.08-1.29), oesophagus (1.22; 1.04-1.43), colorectum (1.09; 1.04-1.15), colon (1.13; 1.06-1.20), liver (1.22; 1.04-1.44) and breast (1.11; 1.02-1.21). Breast cancer risk was marginally associated with drinking pattern, with higher risk when intake was concentrated on 1-3 days/week compared to the same amount spread over 4-7 days (P_interaction = 0.049).

CONCLUSIONS

Alcohol consumption confers a significant risk of cancer, and drinking pattern may be independently related to breast cancer risk.

Etiologic heterogeneity of clear-cell and papillary renal cell carcinoma in the Netherlands Cohort Study

At present, mostly case‐control and retrospective studies have investigated the association between etiologic risk factors and the development of histologic subtypes of renal cell carcinoma (RCC). Therefore, we assessed the heterogeneity between body mass index (BMI), cigarette smoking, alcohol consumption and hypertension across clear‐cell RCC (ccRCC) and papillary RCC (pRCC) risk in the prospective Netherlands Cohort Study on diet and cancer. In 1986, 120 852 participants aged 55 to 69 completed a self‐administered questionnaire on diet and other risk factors for cancer. Participants were followed up for cancer through record linkage. Tumor histology was assessed through centralized revision by two experienced uropathologists. After 20.3 years of follow‐up, 384 histologically verified RCC cases, including 315 ccRCC and 46 pRCC cases and 4144 subcohort members were eligible for case‐cohort analysis. Hazard ratios and 95% confidence intervals were estimated by multivariable‐adjusted proportional hazards models. Overall, BMI was associated positively with ccRCC risk, but inversely with pRCC risk. Cigarette smoking was associated with an increased ccRCC, but a decreased pRCC risk. Alcohol consumption was inversely associated with both ccRCC and pRCC risk. Hypertension was associated with an increased risk of both ccRCC and pRCC. Statistically significant etiologic heterogeneity was observed for BMI, BMI change since age 20, and smoking duration in current smokers across ccRCC and pRCC risk. In conclusion, we observed potential heterogeneity for BMI, BMI change and smoking duration across ccRCC and pRCC risk.

What's new?

Etiologic risk factors for clear cell renal cell carcinoma (ccRCC) and papillary renal cell carcinoma (pRCC) include alcohol consumption, body mass index (BMI), cigarette smoking, and hypertension. Little is known, however, about variability in how these factors affect the development of RCC histologic subtypes. In this population‐based prospective cohort study, examination of variability in associations between established etiologic factors and RCC histologic subtypes revealed significant heterogeneity between BMI and ccRCC and pRCC risk and between risk of these subtypes and smoking duration in current smokers. The findings provide novel insight into relationships between etiologic heterogeneity and mechanisms of RCC development.

Alcohol Consumption Can be a "Double-Edged Sword" for Chronic Kidney Disease Patients

Excessive drinking of alcohol is becoming a worldwide problem, and people have recognized that there exists a close relationship between chronic kidney disease (CKD) and alcohol consumption. However, there are many inconsistencies between experimental and clinical studies on alcohol consumption and kidney damage. The possible reason for this contradictory conclusion is the complex drinking pattern of humans and some bioactivators in wine. In addition, the design itself of the clinical studies can also produce conflicting interpretations of the results. Considering the benefits of light-to-moderate alcohol consumption, we recommend that CKD patients continue light-to-moderate drinking, which is beneficial to them. Because alcohol consumption can lead to adverse events, we do not advise non-drinkers to start to drink. Although light-to-moderate alcohol consumption may not pose a risk to patients with CKD, the patients’ condition needs to be considered. Consumption of even small amounts of alcohol can be associated with increased death risk. Additional clinical and experimental studies are needed to clarify the effect of alcohol on the kidneys and alcohol consumption on CKD patients.

Alcohol Drinking and the Risk of Chronic Kidney Damage: A Meta-Analysis of 15 Prospective Cohort Studies

The relationship between alcohol drinking and chronic kidney damage, mainly including declined glomerular filtration rate (GFR), proteinuria, and end-stage renal disease, was conflicting. Thus, a meta-analysis was conducted to investigate their potential associations. PubMed and Web of Science were searched to identify prospective studies assessing the associations between alcohol drinking and chronic kidney damage published up to March 2019. Random-effects model was employed to pool the relative risks (RR) with 95% confidence intervals (CIs). Subgroup meta-analyses stratified by the basic characteristics of subjects were performed. A total of 15 cohort studies were included in the present study, with 268,723 participants and 31,766 incident cases. Participants with low (<13 g/d), moderate (13 to 26 g/d), and high (26 to 60 g/d) dose of alcohol drinking had 12% (RR: 0.88, 95% CI: 0.83 to 0.93), 24% (RR: 0.76, 95% CI: 0.70 to 0.83), and 21% (RR: 0.79, 95% CI: 0.71 to 0.88) lower risk of chronic kidney damage compared with the reference group (non- or occasional drinkers), respectively. The lower risk for chronic kidney damage remained significant for the declined GFR, or in men, or for participants aged less than 55 yrs, or studies with longer than 8 yrs of follow-up, while severe alcohol drinking (≥60 g/d) insignificantly increased 7% risk of chronic kidney damage (RR: 1.07, 95% CI: 0.53 to 2.15). No obvious heterogeneity and no publication bias were observed. Based on our meta-analysis, participants with alcohol drinking less than 60 g/d were at lower risk of declined GFR, especially in men or participants aged less than 55 yrs. Much more prospective cohort studies are required to confirm our present findings.

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) (pinteraction  = 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 posteriori dietary patterns and risk of pancreatic and renal cancers

Purpose

Dietary patterns have been used to explore the association between dietary factors and risk of pancreatic cancer (PC) and renal cancer (RC); however, the association remains unclear. The purpose of this paper is to comprehensively review these associations.

Design/methodology/approach

Pertinent studies published prior to March 2016 were systematically searched and retrieved through PubMed and Scopus databases. Adjusted risk estimates were derived by comparing the highest with the lowest categories of dietary pattern scores and were combined by using the fixed-effects model when no substantial heterogeneity was observed; otherwise, the random-effects model was used.

Findings

A total of nine studies, five for PC (including 2,059 cases and 41,774 participants/controls) and four for RC (with 1,327 cases and 53,007 participants/controls), were included in this meta-analysis. A decreased risk of PC was shown for the highest compared with the lowest categories of the healthy dietary pattern (OR = 0.72, 95 per cent CI = 0.51-0.94, random effects (p-value for heterogeneity = 0.004)), whereas no significant association with Western dietary was observed (OR = 1.16, 95 per cent CI = 0.87-1.44, fixed effects). In the overall analysis, a significant association was found between the healthy dietary pattern and reduced risk of RC (OR = 0.59, 95 per cent CI = 0.48-0.71, fixed effects (p-value for heterogeneity = 0.459)), whereas the Western pattern was positively associated with risk of RC (OR = 1.42, 95 per cent CI = 1.14-1.69, fixed effects). For both cancers, the reduced risk associated with the healthy pattern was restricted to case-control, but not cohort, studies. Furthermore, drinking pattern was significantly related to reduced risk of RC (OR = 0.68, 95 per cent CI = 0.42-0.94).

Originality/value

To the authors’ knowledge, the present study is the first English document to summarize systematically the findings from observational studies in response to this question whether a posteriori dietary patterns are associated with susceptibility to the risk of renal and ovarian cancers.

Renal cell carcinoma: links and risks

This review provides an overview of the incidence of renal cell carcinoma (RCC) and a summary of the most commonly associated risk factors. A literature review was performed with a focus on recent studies with a high level of evidence (large prospective cohort studies and meta-analyses). The incidence rate of RCC varies globally, with the rate rising rapidly in more developed regions, demonstrating the effects of increased use of diagnostic imaging and prevalence of modifiable risk factors. Based on the current evidence, cigarette smoking, obesity, and hypertension are the most well-established risk factors for sporadic RCC worldwide. Acquired cystic kidney disease is also a significant risk factor, specifically in dialysis patients. There is increasing evidence for an inverse association between RCC risk and moderate alcohol consumption. Certain analgesics and occupational exposure have been linked to an increased risk of RCC, although data are limited. Diets rich in fruits and vegetables may provide a protective effect.

A meta-analysis including dose-response relationship between night shift work and the risk of colorectal cancer

A meta-analysis was conducted to quantitatively evaluate the correlation between night shift work and the risk of colorectal cancer. We searched for publications up to March 2015 using PubMed, Web of Science, Cochrane Library, EMBASE and the Chinese National Knowledge Infrastructure databases, and the references of the retrieved articles and relevant reviews were also checked. OR and 95% CI were used to assess the degree of the correlation between night shift work and risk of colorectal cancer via fixed- or random-effect models. A dose-response meta-analysis was performed as well. The pooled OR estimates of the included studies illustrated that night shift work was correlated with an increased risk of colorectal cancer (OR = 1.318, 95% CI 1.121-1.551). No evidence of publication bias was detected. In the dose-response analysis, the rate of colorectal cancer increased by 11% for every 5 years increased in night shift work (OR = 1.11, 95% CI 1.03-1.20). In conclusion, this meta-analysis indicated that night shift work was associated with an increased risk of colorectal cancer. Further researches should be conducted to confirm our findings and clarify the potential biological mechanisms.