Diabetes mellitus and incidence and mortality of kidney cancer: a meta-analysis

A population-based study on incidence trends of kidney and renal pelvis cancers in the United States over 2000-2020

Cancers of the kidney and renal pelvis are among the most prevalent types of urinary cancers. We aimed to outline the incidence trends of kidney and renal pelvis cancers by age, sex, race/ethnicity, and histology in the United States (US) from 2000 to 2020. The data was obtained from the Surveillance, Epidemiology, and End Results (SEER) 22 database. The identification of patients with kidney and renal pelvis cancers with morphologies of renal cell carcinoma, nephroblastoma, sarcoma, and neuroendocrine tumor was conducted utilizing the International Classification of Diseases for Oncology version 3. The average annual percent change (AAPC) were presented. All estimates were given in the form of counts and delayed age-standardized incidence rates (ASIRs) per 100,000 people. From 2000 to 2019, a total of 490,481 cases of kidney and renal pelvic cancer were recorded across all age groups in the US. The majority of them were among Non-Hispanic Whites (NHWs) (69.75%) and those aged 55-69 years (39.96%). The ASIRs per 100,000 for kidney and pelvis cancers were 22.03 for men and 11.14 for women. Non-Hispanic Black men had the highest ASIR (24.53 [24.24, 24.81]), and increase in ASIR over the 2000-2019 period (AAPC: 2.19% [1.84, 2.84]). There was a noticeable increase in incidence of kidney and renal pelvis cancers. Individuals aged 70-84 years had the highest ASIR for kidney and renal pelvis cancers. The COVID-19 era has resulted in a significant reduction in incidence rates across all demographics.

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.

Effect of chronic viral hepatitis and metabolic factors on renal cancer risk in a large cohort in Republic of Korea

PURPOSE

We investigated the association between hepatic and metabolic factors and renal cancer risk.

METHODS

This population-based cohort study included cancer-free individuals who underwent general health evaluation (January to December 2010) at the Korean National Health Insurance Service and followed-up through 2017. Hazard ratios (HR) and 95% confidence intervals (CI), determined by adjusted Cox regression analysis were used to investigate the effect of variables on renal cancer risk.

RESULTS

Among 4,518,704 subjects, 6531 patients developed renal cancer. Adjusted analyses of epidemiological factors and BMI (body mass index) (Model I) showed serum high-density lipoprotein cholesterol (HDL-C) ≥60 mg/dL (adjusted HR [aHR] 0.88, 95% CI, 0.81-0.95) reduced renal cancer risk comparing to low HDL-C, whereas hepatitis B virus (HBV) antigen (aHR 1.41, 95% CI 1.19-1.68) and chronic HBV infection (aHR 1.65, 95% CI 1.26-2.17) increased its risk. Higher BMI increased renal cancer risk in dose-dependent manner (P for trend <0.001). This association persisted after adjustment for epidemiological factors and waist circumference (Model II). Sex-specific analyses showed similar effect of HBV antigen and chronic HBV infection in both sexes. Normal (50-59 mg/dL in women) or high (≥60 mg/dL in men) HDL-C reduced renal cancer risk. Alcohol consumption increased kidney cancer risk in age ≥ 60 years, but it had no association with renal cancer in age < 60 years.

CONCLUSIONS

High serum HDL-C levels reduced and HBV antigen and chronic HBV infection increased renal cancer risk across different adjusted analysis models. This effect of low HDL-C and chronic HBV infection persisted in sex-based subanalysis.

Disparities and Trends in Genitourinary Cancer Incidence and Mortality in the USA

BACKGROUND

Previous studies have reported on incidence and mortality patterns for individual genitourinary cancers in the USA. However, these studies addressed individual cancer types rather than genitourinary cancers overall.

OBJECTIVE

To comprehensively examine disparities and trends in the incidence and mortality for the four major genitourinary cancers (bladder, kidney, prostate, and testis) in the USA.

DESIGN, SETTING, AND PARTICIPANTS

We obtained incidence data from the National Cancer Institute 22-registry Surveillance, Epidemiology and End Results (SEER) database and the US Cancer Statistics database (Centers for Disease Control and Prevention) and mortality data from the National Center for Health Statistics to examine cross-sectional and temporal trends in incidence and death rates stratified by sex, race/ethnicity, and county.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Age-adjusted incidence and death rates were calculated using SEER*Stat software. Temporal trends were analyzed using Joinpoint regression for a two-sided significance level of p < 0.05.

RESULTS AND LIMITATIONS

Incidence and mortality rates for bladder and kidney cancers were two to four times higher for men than for women. Among non-Hispanic White individuals, the highest incidence rates were found in the Northeast for bladder cancer and in Appalachia for kidney cancer, whereas the highest death rates for prostate cancer were found in the West. Incidence rates increased for cancers of the kidney and testis and for advanced-stage prostate cancer in almost all racial/ethnic populations and for bladder cancer in the American Indian/Alaska Native population. Death rates increased for testicular cancer in the Hispanic population and stabilized for prostate cancer among White and Asian American/Pacific Islander men after a steady decline since the early 1990s. Study limitations include misclassification of race/ethnicity on medical records and death certificates.

CONCLUSIONS

We found persistent sociodemographic disparities and unfavorable trends in incidence or mortality for all four major genitourinary cancers. Future studies should elucidate the reasons for these patterns.

PATIENT SUMMARY

In the USA, rates of cancer cases are increasing for kidney, testis, and advanced-stage prostate cancers in the overall population, and for bladder cancer in the American Indian/Alaska Native population. Differences in the rates by sex and race/ethnicity remain.

Recent Advances in the Management of Clear Cell Renal Cell Carcinoma: Novel Biomarkers and Targeted Therapies

Renal cell carcinoma (RCC) belongs to a heterogenous cancer group arising from renal tubular epithelial cells. Among RCC subtypes, clear cell renal cell carcinoma (ccRCC) is the most common variant, characterized by high aggressiveness, invasiveness and metastatic potential, features that lead to poor prognosis and high mortality rate. In addition, diagnosis of kidney cancer is incidental in the majority of cases, and this results in a late diagnosis, when the stage of the disease is advanced and the tumor has already metastasized. Furthermore, ccRCC treatment is complicated by its strong resistance to chemo- and radiotherapy. Therefore, there is active ongoing research focused on identifying novel biomarkers which could be useful for assessing a better prognosis, as well as new molecules which could be used for targeted therapy. In this light, several novel targeted therapies have been shown to be effective in prolonging the overall survival of ccRCC patients. Thus, the aim of this review is to analyze the actual state-of-the-art on ccRCC diagnosis, prognosis and therapeutic options, while also reporting the recent advances in novel biomarker discoveries, which could be exploited for a better prognosis or for targeted therapy.

Association of Metabolic Syndrome Components and Nutritional Status with Kidney Cancer in Young Adult Population: A Nationwide Population-Based Cohort Study in Korea

The aim of this study was to determine the association of metabolic syndrome (MetS) with kidney cancer and the impact of age and gender on such an association. Using the Korean National Health Insurance Service database, 9,932,670 subjects who had check-ups in 2009 were followed up until the diagnosis of kidney cancer or death or until 2019. Kidney cancer was significantly associated with MetS (HR 1.56). This association was higher in the younger age group (HR: 1.82, 1.5, and 1.37 in 20-39 years, 40-64 years, and ≥65 years, respectively). In terms of the association of kidney cancer with obesity and central obesity, young-aged males showed higher HR for kidney cancer than old-aged ones (HR of obesity: 1.96, 1.52, and 1.25; HR of central obesity: 1.94, 1.53, and 1.3 in 20-39 years, 40-64 years, ≥65 years, respectively), while young-aged females showed lower HR. Kidney cancer was associated with obesity and MetS. The association was higher in younger populations than in older ones. Regarding gender, MetS, obesity, and central obesity showed higher associations with kidney cancer in younger aged male population, while there was no significant difference in such associations according to age in the female population.

Post-transplant diabetes mellitus and renal cell cancer after renal transplantation

Background

Diabetes is a risk factor for cancer in the general population. However, few data are available on the association between post-transplant diabetes mellitus (PTDM) and cancer after transplantation.

Methods

We analyzed this issue in a Spanish cohort of patients without diabetes before transplantation. PTDM was diagnosed with consensus criteria at 12 months after transplantation and 12 months before the diagnosis of cancer. The association between PTDM and cancer (overall and specific types) was evaluated with regression analysis.

Results

During a follow-up of 12 years (interquartile range 8–14), 85 cases of 603 developed cancer (829/100 000/year) and 164 (27%) PTDM. The most frequent cancers were renal cell cancer (RCC) n = 15, 146/cases/100 000/year), lung (n = 12, 117/cases/100 000/year), colon (n = 9, 88/cases/100 000/year) and prostate (n = 9, 88/cases/100 000/year). In logistic regression, PTDM was not associated with cancer. Eight of the 164 patients with PTDM (4.9%) vs 7 of the 439 without PTDM developed RCC (1.6%) (P = .027). In multivariate analysis, PTDM was independently associated with RCC [odds ratio (OR) 2.92, confidence interval (CI) 1.03–8.27], adjusting for smoking (OR 4.020, 95% CI 1.34–12.02) and other covariates. PTDM was not associated with other types of cancer.

Conclusions

Patients with PTDM must be considered a population at risk for RCC and accordingly, the subject of active surveillance.

Prospective associations of hemoglobin A1c and c-peptide with risk of diabetes-related cancers in the Cancer Prevention Study-II Nutrition Cohort

Self-reported type 2 diabetes mellitus (T2DM) is a risk factor for many cancers, suggesting its pathology relates to carcinogenesis. We conducted a case-cohort study to examine associations of hemoglobin A1c (HbA1c) and c-peptide with cancers associated with self-reported T2DM. This study was drawn from a prospective cohort of 32,383 women and men who provided blood specimens at baseline: c-peptide and HbA1c were assessed in 3,000 randomly selected participants who were cancer-free-at-baseline and an additional 2,281 participants who were cancer-free-at-baseline and subsequently diagnosed with incident colorectal, liver, pancreatic, female breast, endometrial, ovarian, bladder, or kidney cancers. Weighted-Cox regression models estimated hazards ratios (HRs) and 95% confidence intervals (CI), adjusted for covariates. C-peptide was associated with higher risk of liver cancer (per standard deviation (SD) HR: 1.80; 95%CI: 1.32-2.46). HbA1c was associated with higher risk of pancreatic cancer (per SD HR: 1.21 95%CI 1.05-1.40) and with some suggestion of higher risks for all-cancers-of-interest (per SD HR: 1.05; 95%CI: 0.99-1.11) and colorectal (per SD HR: 1.09; 95%CI: 0.98-1.20), ovarian (per SD HR: 1.18; 95%CI 0.96-1.45) and bladder (per SD HR: 1.08; 95%CI 0.96-1.21) cancers. Compared to no self-reported T2DM and HbA1c <6.5% (reference group), self-reported T2DM and HbA1c <6.5% (i.e., T2DM in good glycemic control) was not associated with risk of colorectal cancer, whereas it was associated with higher risks of all-cancers-of-interest combined (HR: 1.28; 95%CI: 1.01-1.62), especially for breast and endometrial cancers. Additional large, prospective studies are needed to further explore the roles of hyperglycemia, hyperinsulinemia, and related metabolic traits with T2DM-associated cancers to better understand the mechanisms underlying the self-reported T2DM-cancer association and to identify persons at higher cancer risk.

Association Between Diabetes and the Risk of Kidney Cancer: Systematic Review and Meta-Analysis

Diabetes is a risk factor for several types of cancer, but the specific relationship between diabetes and kidney cancer is not well understood. We conducted a search strategy in scientific databases for case-control and cohort studies on this topic. We analyzed 17 studies and found that diabetes was significantly associated with the risk of developing kidney cancer and that this risk was slightly stronger for women and for people living in Asia. These findings were not influenced by obesity, cigarette smoking, or hypertension. We conclude that diabetes is an independent risk factor for the development of kidney cancer.

The association between diabetes and cancer in Mexico: Analysis using death certificate databases, 2009-2017

Context

Previous studies have shown that diabetes mellitus (DM) is a risk factor of some type-specific cancers. However, no data are available on the association between cancer and DM in Latin America.

Aims

The aim of this study is to determine which type-specific cancers are associated with DM using multiple cause of death data.

Settings and Design

Whole country of Mexico, cross-sectional design.

Materials and Methods

Analysis of all cancer deaths (2009-2017) using death certificate databases of Mexican adults aged ≥20 years.

Statistical Analysis Used

Multivariable logistic regression.

Results

There were 710,292 total cancer deaths. DM increased the risk of pancreatic (adjusted odds ratio [aOR] = 1.7), liver (aOR = 1.6), kidney (aOR = 1.4), gallbladder (aOR = 1.2) and endometrial (aOR = 1.1) cancers, all P < 0.05. Type 2 or unknown-type DM were associated with the same cancer types with little variation of estimates. Higher estimates were found in males than females (except for kidney cancer). Type 1 DM was associated with pancreatic cancer only (aOR = 1.9).

Conclusions

DM in Mexico is associated with gastrointestinal (pancreatic, liver, gallbladder), kidney and endometrial cancers. Dissemination of knowledge to both health-care workers and diabetics regarding potential cancer risks including adequate diet, regular exercise, weight reduction if obese/overweight, cessation of smoking, and good glucose control and medication compliance should be reinforced. Specific cancer preventative measures should be implemented for patients with DM.

Risk Prediction Models for Kidney Cancer: A Systematic Review

CONTEXT

Early detection of kidney cancer improves survival; however, low prevalence means that population-wide screening may be inefficient. Stratification of the population into risk categories could allow for the introduction of a screening programme tailored to individuals.

OBJECTIVE

This review will identify and compare published models that predict the risk of developing kidney cancer in the general population.

EVIDENCE ACQUISITION

A search identified primary research reporting or validating models predicting the risk of kidney cancer in Medline and EMBASE. After screening identified studies for inclusion, we extracted data onto a standardised form. The risk models were classified using the Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis (TRIPOD) guidelines and evaluated using the PROBAST assessment tool.

EVIDENCE SYNTHESIS

The search identified 15 281 articles. Sixty-two satisfied the inclusion criteria; performance measures were provided for 11 models. Some models predicted the risk of prevalent undiagnosed disease and others future incident disease. Six of the models had been validated, two using external populations. The most commonly included risk factors were age, smoking status, and body mass index. Most of the models had acceptable-to-good discrimination (area under the receiver-operating curve >0.7) in development and validation. Many models also had high specificity; however, several had low sensitivity. The highest performance was seen for the models using only biomarkers to detect kidney cancer; however, these were developed and validated in small case-control studies.

CONCLUSIONS

We identified a small number of risk models that could be used to stratify the population according to the risk of kidney cancer. Most exhibit reasonable discrimination, but a few have been validated externally in population-based studies.

PATIENT SUMMARY

In this review, we looked at mathematical models predicting the likelihood of an individual developing kidney cancer. We found several suitable models, using a range of risk factors (such as age and smoking) to predict the risk for individuals. Most of the models identified require further testing in the general population to confirm their usefulness.

Insulin Resistance and Cancer: In Search for a Causal Link

Insulin resistance (IR) is a condition which refers to individuals whose cells and tissues become insensitive to the peptide hormone, insulin. Over the recent years, a wealth of data has made it clear that a synergistic relationship exists between IR, type 2 diabetes mellitus, and cancer. Although the underlying mechanism(s) for this association remain unclear, it is well established that hyperinsulinemia, a hallmark of IR, may play a role in tumorigenesis. On the other hand, IR is strongly associated with visceral adiposity dysfunction and systemic inflammation, two conditions which favor the establishment of a pro-tumorigenic environment. Similarly, epigenetic modifications, such as DNA methylation, histone modifications, and non-coding RNA, in IR states, have been often associated with tumorigenesis in numerous types of human cancer. In addition to these observations, it is also broadly accepted that gut microbiota may play an intriguing role in the development of IR-related diseases, including type 2 diabetes and cancer, whereas potential chemopreventive properties have been attributed to some of the most commonly used antidiabetic medications. Herein we provide a concise overview of the most recent literature in this field and discuss how different but interrelated molecular pathways may impact on tumor development.

The biological and pharmacological connections between diabetes and various types of cancer

Diabetes and cancer incidence have risen tremendously over the years. Additionally, both cancer and diabetes share numerous risks, such as overweight, inactive lifestyles, older age, and smoking. Numerous methods have been suggested to connect obesity and diabetes to cancer advancements, such as increasing insulin/ Insulin-like growth factor I (IGF-1) signaling, lipid and glucose uptake and metabolism, shifts in the cytokine, chemokine, and adipokine profile also variations in the adipose tissue immediately adjacent to cancer spots. Diabetes has been found to have a complicated cancer-causing mechanism involving excessive reactive oxygen species (ROS) production, loss of critical macromolecules, chronic inflammation, and delayed repair, all of which contribute to carcinogenesis. Diabetes-associated epithelial-to-mesenchymal transition and endothelial-to-mesenchymal transition lead to the formation of cancer-associated fibroblasts in tumors by enabling tumor cells to extravasate via the endothelium and epithelium. This study aims to describe the correlation between diabetes and cancer, as well as summarize the molecular connections and shared pathways such as sex hormones, hyperglycemia, inflammation, insulin axis, metabolic symbiosis, and endoplasmic reticulum (ER) stress that exist between them.

Type 2 Diabetes and Cancer: An Umbrella Review of Observational and Mendelian Randomization Studies

BACKGROUND

Type 2 diabetes mellitus (T2DM) has been associated with an increased risk of developing several common cancers, but it is unclear whether this association is causal. We aimed to summarize the evidence on T2DM and cancer and evaluate the validity of associations from both observational and Mendelian randomization (MR) studies.

METHODS

We performed an umbrella review of the evidence across meta-analyses of observational studies that examined associations of T2DM with risk of developing or dying from site-specific cancers, and MR studies that explored the potential causal association of T2DM and associated biomarkers with cancer risk.

RESULTS

We identified eligible observational meta-analyses that assessed associations between T2DM and cancer incidence for 18 cancer sites, cancer mortality for seven sites, and cancer incidence or mortality for four sites. Positive associations between T2DM and six cancers reached strong or highly suggestive evidence. We found eight MR studies assessing the association of genetically predicted T2DM and seven and eight studies assessing the association of genetically predicted fasting insulin or fasting glucose concentrations, respectively, upon site-specific cancers. Positive associations were found between genetically predicted T2DM and fasting insulin and risk of six cancers. There was no association between genetically predicted fasting plasma glucose and cancer except for squamous cell lung carcinoma.

CONCLUSIONS

We found robust observational evidence for the association between T2DM and colorectal, hepatocellular, gallbladder, breast, endometrial, and pancreatic cancers.

IMPACT

Potential causal associations were identified for genetically predicted T2DM and fasting insulin concentrations and risk of endometrial, pancreas, kidney, breast, lung, and cervical cancers.

High circulating insulin-like growth factor-1 reduces the risk of renal cell carcinoma: a Mendelian randomization study

Insulin and insulin-like growth factors play important roles in carcinogenesis. Circulating insulin-like growth factor-1 (IGF-1) and insulin-like growth factor-binding protein-3 (IGFBP-3) have been linked to cancer susceptibility. The associations of circulating IGF-1 and IGFBP-3 with the risk of renal cell carcinoma (RCC) are inconsistent. Recent large genome-wide association studies have identified 413 single nucleotide polymorphisms (SNPs) associated with IGF-1 and 4 SNPs associated with IGFBP-3. In this large case-control study consisting of 2069 RCC patients and 2052 healthy controls of European ancestry, we used a two-sample Mendelian randomization (MR) approach to investigate the associations of genetically predicted circulating IGF-1 and IGFBP-3 with RCC risk. We used an individual level data-based genetic risk score (GRS) and a summary statistics-based inverse-variance weighting (IVW) method in MR analyses. We found that genetically predicted IGF-1 was significantly associated with RCC risk in both the GRS analysis [odds ratio (OR) = 0.43 per SD increase, 95% confidence interval (CI), 0.34-0.53] and the IVW analysis (OR = 0.46 per SD increase, 95% CI, 0.37-0.57). Dichotomized at the median GRS value of IGF-1 in controls, individuals with high GRS had a 45% reduced RCC risk (OR = 0.55, 95% CI, 0.48-0.62) compared with those with low GRS. Genetically predicted circulating IGFBP-3 was not associated with RCC risk. This is the largest RCC study of circulating IGF-1 and IGFBP-3 to date and our data suggest a strong inverse relationship between circulating IGF-1 level and RCC risk.

Short-Chain Fatty Acids: A Soldier Fighting Against Inflammation and Protecting From Tumorigenesis in People With Diabetes

Converging evidences showed that people with diabetes mellitus (DM) have significantly higher risk for different cancers, of which the exact mechanism underlying the association has not been fully realized. Short-chain fatty acids (SCFAs), the fermentation products of the intestinal microbiota, are an essential source for energy supply in gut epithelial cells. They have been reported to improve intestinal barrier integrity, prevent microbial translocation, and further dampen inflammation. Gut dysbiosis and reduction in SCFA-producing bacteria as well as SCFAs production in the intestine are commonly seen in metabolic disorders including DM and obesity. Moreover, inflammation can contribute to tumor initiation and progression through multiple pathways, such as enhancing DNA damage, accumulating mutations in tumor suppressor genes Tp53, and activating nuclear factor-kappa B (NF-κB) signaling pathways. Based on these facts, we hypothesize that lower levels of microbial SCFAs resulted from gut dysbiosis in diabetic individuals, enhance microbial translocation, and increase the inflammatory responses, inducing tumorigenesis ulteriorly. To this end, we will discuss protective properties of microbial SCFAs and explore the pivotal roles SCFAs played in the link of DM with cancer, so as to take early precautions to reduce the risk of cancer in patients with DM.

Increased kidney cancer risk in diabetes mellitus patients: a population-based cohort study in Lithuania

BACKGROUND

Diabetes is associated with increased risk of various cancers but its association with kidney cancer is unclear. The objective of this study was to evaluate the association between T2DM with or without metformin use and the risk of kidney cancer in a population-based national cohort in Lithuania.

METHODS

The cohort was composed of diabetic patients identified in the NHIF database during 2000-2012. Cancer cases were identified by record linkage with the national Cancer Registry. Standardized incidence ratios (SIRs) for kidney cancer as a ratio of observed number of cancer cases in diabetic patients to the expected number of cancer cases in the underlying general population were calculated.

RESULTS

T2DM patients (11,592) between 2000 and 2012 were identified. Overall, 598 cases of primary kidney cancer were identified versus 393.95 expected yielding an overall SIR of 1.52 (95% CI: 1.40-1.64). Significantly higher risk was found in males and females. Significantly higher risk of kidney cancer was also found in both metformin users and never-users' groups (SIRs 1.45, 95% CI: 1.33-1.60 and 1.78 95% CI: 1.50-2.12, respectively).

CONCLUSIONS

The patients with T2DM have higher risk for kidney cancer compared with the general Lithuanian population.

Modulation of Calcium Homeostasis May Be Associated with Susceptibility to Renal Cell Carcinoma in Diabetic Nephropathy Rats

Introduction

Clinical studies have indicated a relationship between diabetic nephropathy (DN) and the incidence and prevalence of renal cell carcinoma (RCC). However, the mechanism linking diabetic nephropathy and renal cell carcinoma has not yet to be identified.

Methods

In this study, a total of 42 male Sprague Dawley (SD) rats were randomly assigned to a DN group (n=35) and a control group (n=7). All animals in the DN group were unilaterally nephrectomized and treated with streptozotocin with the development of blood glucose levels >16.7mmol/L and dominant proteinuria and were compared to controls without such changes. Histopathologic alterations in the kidneys were examined by HE staining and Ki-67 immunohistochemistry. Differentially expressed genes were identified and validated by RNA-seq and PCR.

Results

As the results, except for two rats that failed to develop the DN model and were excluded from the analysis, 33 rats in the DN group with overt signs of DN demonstrated significantly higher food and water intake, urine production, and urine protein and urinary protein/creatinine ratio than controls. Overall, 15.2% (n=5/33) of DN animals developed RCC while none tumors were observed in the control group (n=0/7). RNA-seq analysis in these animals indicated different TRPV5 gene expression and calcium pathway expression in DN animals with developing tumors, when compared with animals with no obvious tumors. In addition, DN animals diagnosed with RCC showed increased expression of GLUT2 and c-met, when compared to controls and DN animals without tumors.

Discussion

In conclusion, the disordered calcium metabolism, especially disturbed TRPV5 mediated Ca²⁺ signal, may have been related to the development of RCC in DN rats. Further studies related to the detailed mechanism are still needed.

The Role of Metabolic Factors in Renal Cancers

An increasing number of evidence indicates that metabolic factors may play an important role in the development and progression of certain types of cancers, including renal cell carcinoma (RCC). This tumour is the most common kidney cancer which accounts for approximately 3-5% of malignant tumours in adults. Numerous studies indicated that concomitant diseases, including diabetes mellitus (DM) and hypertension, as well as obesity, insulin resistance, and lipid disorders, may also influence the prognosis and cancer-specific overall survival. However, the results of studies concerning the impact of metabolic factors on RCC are controversial. It appears that obesity increases the risk of RCC development; however, it may be a favourable factor in terms of prognosis. Obesity is closely related to insulin resistance and the development of diabetes mellitus type 2 (DM2T) since the adipocytes in visceral tissue secrete substances responsible for insulin resistance, e.g., free fatty acids. Interactions between insulin and insulin-like growth factor (IGF) system appear to be of key importance in the development and progression of RCC; however, the exact role of insulin and IGFs in RCC pathophysiology remains elusive. Studies indicated that diabetes increased the risk of RCC, but it might not alter cancer-related survival. The risk associated with a lipid profile is most mysterious, as numerous studies provided conflicting results. Even though large studies unravelling pathomechanisms involved in cancer growth are required to finally establish the impact of metabolic factors on the development, progression, and prognosis of renal cancers, it seems that the monitoring of health conditions, such as diabetes, low body mass index (BMI), and lipid disorders is of high importance in clear-cell RCC.

Incidence of Bladder Cancer in Type 2 Diabetes Mellitus Patients: A Population-Based Cohort Study

Background and objectives: Type 2 diabetes mellitus (T2DM) is becoming increasingly prevalent worldwide and is associated with increased incidence of kidney cancer and bladder cancer (BC). However, studies have produced conflicting results. Therefore, we retrospectively evaluated the incidence of BC in T2DM patients using the Taiwan National Health Insurance Research Database (NHIRD). Materials and Methods: We included 31,932 patients with a diagnosis of T2DM in the study group and 63,864 age- and sex-matched patients without T2DM at a ratio of 1:2 in the control group. The primary outcome was the diagnosis of BC. Cox proportional hazards regression was used to evaluate the incidence and adjusted hazard ratio (aHR) of BC in the multivariate model. Results: After a 16-year follow-up, we found that 67 BC cases occurred in the study group and 152 BC events in the non-T2DM group without a significantly higher risk (aHR: 0.842, 95% confidence interval: 0.627–1.13). Conclusions: T2DM patients do not have a higher risk of BC.

Diabetes and kidney cancer risk among post-menopausal women: The Iowa women's health study

BACKGROUND

Many studies have reported a positive association between diabetes and kidney cancer. However, it is unclear whether diabetes is a risk factor for kidney cancer independent of other risk factors, such as obesity and hypertension. We comprehensively examined the association of diabetes and its duration with incident kidney cancer in the prospective cohort Iowa Women's Health Study (1986-2011).

METHODS

Diabetes status was self-reported at baseline (1986) and on five follow-up questionnaires. Cox proportional hazards regression was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for the associations of baseline and time-dependent diabetes with the risk of incident kidney cancer.

RESULTS

During the 25 years of follow-up, 245 cases of kidney cancer occurred among 36,975 post-menopausal women. In an age-adjusted model, there was a significant association between time-dependent diabetes and the risk of kidney cancer [HR (95% CI) = 1.76 (1.26, 1.45)]; the association was attenuated after multivariable adjustment for age, body mass index (BMI), waist-to-hip ratio (WHR), hypertension, physical activity, diuretic use, pack-years of smoking, alcohol intake, and total caloric intake [HR = 1.35 (0.94, 1.94)]. However, among non-obese women or women with a waist circumference less than 34.6 in., diabetes was significantly associated with kidney cancer risk: for time-dependent diabetes, HRs (95% CIs) were 1.82 (1.10, 3.00) among those with BMI < 30 kg/m² and 2.18 (1.08, 4.38) among those with a waist circumference <34.6 in..

CONCLUSIONS

Our results suggest that diabetes is associated with kidney cancer risk among non-obese post-menopausal women.

The Role of Diet in Cancer Prevention and Chemotherapy Efficacy

Despite great advances in treatment, cancer remains a leading cause of death worldwide. Diet can greatly impact health, while caloric restriction and fasting have putative benefits for disease prevention and longevity. Strong epidemiological associations exist between obesity and cancer, whereas healthy diets can reduce cancer risk. However, less is known about how diet might impact cancer once it has been diagnosed and particularly how diet can impact cancer treatment. In the present review, we discuss the links between obesity, diet, and cancer. We explore potential mechanisms by which diet can improve cancer outcomes, including through hormonal, metabolic, and immune/inflammatory effects, and present the limited clinical research that has been published in this arena. Though data are sparse, diet intervention may reduce toxicity, improve chemotherapy efficacy, and lower the risk of long-term complications in cancer patients. Thus, it is important that we understand and expand the science of this important but complex adjunctive cancer treatment strategy.

Diabetes, Glycated Hemoglobin, and Risk of Cancer in the UK Biobank Study

BACKGROUND

Evidence suggest that diabetes and glycated hemoglobin (HbA1c) levels are associated with cancer risk. However, previous studies have been limited variably by failure to adjust for cancer-specific risk factors (e.g., body mass index), inattention to diabetes duration and use of antidiabetic medications, and failure to stratify by obesity.

METHODS

We examined the association between diabetes, HbA1c, and cancer risk in the UK Biobank, using data from 476,517 participants (54% women), followed for an average period of 7.1 years. Diabetes was defined on the basis of baseline self-reported diagnosis of diabetes and/or use of diabetes medication, while HbA1c measured at baseline was categorized as low (<31 mmol/mol), normal (31-<39 mmol/mol), increased risk (39-<48 mmol/mol), and high risk for diabetes (≥48 mmol/mol). Multivariable Cox proportional hazards models were used to estimate the association of diabetes and cancer at different anatomical sites, with adjustment for cancer-specific risk factors.

RESULTS

Diabetes was associated with increased risk of cancers of the stomach, liver, bladder, endometrium, and lung among smokers, and with decreased risk of prostate cancer. Compared with the normal HbA1c category, the increased risk category was positively associated with risk of cancers of the colon, liver, bladder, and lung among smokers, and the high-risk category was associated with increased risk of cancers of the esophagus, liver, pancreas, and bladder, and with decreased risk of prostate cancer.

CONCLUSIONS

These results suggest that both diabetes and/or elevated HbA1c are associated with risk of cancer at several anatomic sites.

IMPACT

The associations of diabetes and HbA1c levels with cancer suggest their importance in cancer prevention.

Type 2 diabetes mellitus predicts worse outcomes in patients with high-grade T1 bladder cancer receiving bacillus Calmette-Guérin after transurethral resection of the bladder tumor

OBJECTIVES

The aim of this multicenter study was to investigate the prognostic role of type 2 diabetes mellitus (T2DM) comorbidity in a large multi-institutional cohort of patients with primary T1HG/G3 non-muscle-invasive bladder cancer (NMIBC) treated with transurethral resection of the bladder (TURB).

MATERIALS AND METHODS

A total of 1,172 patients with primary T1 HG/G3 who had NMIBC on re-TURB and who received adjuvant intravesical bacillus Calmette-Guérin therapy with maintenance were included. Endpoints were recurrence-free survival and progression-free survival.

RESULTS

A total of 231 (19.7%) of patients had T2DM prior to TURB. Five-year recurrence-free survival estimates were 12.5% in patients with T2DM compared to 36% in patients without T2DM, P < 0.0001. Five-year PFS estimates were 60.5% in patients with T2DM compared to 70.2% in patients without T2DM, P = 0.003. T2DM was independently associated with disease recurrence (hazard ratio = 1.41; 95% confidence interval = 1.20-1.66, P < 0.001) and progression (hazard ratio = 1.27; 95% confidence interval = 0.99-1.63, P < 0.001), after adjusting for other known predictive factors such as tumor size, multifocality, T1G3 on re-TURB, body mass index, lymphovascular invasion, and neutrophil-to-lymphocytes ratio.

CONCLUSIONS

Given the potential implications for management, prospective validation of this finding along with translational studies designed to investigate the underlying biology of such an association are warranted.

Type 2 diabetes and colorectal cancer screening: Findings from the English Longitudinal Study of Ageing

Objectives

Type 2 diabetes has been identified as a risk factor for colorectal cancer, but little is known about whether it influences participation in colorectal cancer screening programmes. This study tested the extent to which Type 2 diabetes is negatively associated with colorectal cancer screening uptake.

Methods

We analysed individual data of screening eligible men and women aged 60–75 without cancer diagnosis from wave 6 of the English Longitudinal Study of Ageing (collected 2012–2013), to investigate whether Type 2 Diabetes influences colorectal cancer screening behaviour independently of demographic characteristics, body mass index, socio-economic status and other chronic diseases.

Results

Individuals who reported to have Type 2 diabetes or had glycated haemoglobin (HbA1c) levels of 48 mmol/mol or higher were less likely to have ever completed a screening test (faecal occult blood test; 62.8% vs. 75.8%, p < 0.01) or to be up-to-date with their biennial screening invitation (60.2% vs. 72.0%, p < 0.05). The negative associations of Type 2 diabetes on colorectal cancer screening were found both in unadjusted and adjusted regression models.

Conclusions

Future qualitative and quantitative research should identify reasons for this discrepancy, to inform interventions to increase screening uptake in this high-risk population.

Increased Risk of Site-Specific Cancer in People with Type 2 Diabetes: A National Cohort Study

A retrospective cohort design was used with the objective to evaluate cancer risk among people with type 2 diabetes mellitus (T2DM) in Lithuania. The cohort was established by identifying all patients with the first diagnosis of T2DM in the National Health Insurance Fund database during 2000-2012. Cancer cases were identified by record linkage with the Lithuanian Cancer Registry. Standardized incidence ratios (SIRs) were calculated. Of the 127,290 people that were included, 5959 cases of cancer in men and 6661 cancer cases in women with T2DM were observed. A statistically significant increase in risk for all cancer sites was observed in women, SIR 1.16 (95% CI 1.14-1.19), but not in men, SIR 1.00 (95% CI 0.98-1.03). Among males, a significant increase of liver (SIR 2.11, 95% CI 1.79-2.49]), pancreas (SIR 1.77, 95% CI 1.57-1.99), kidney (SIR 1.46 95% CI 1.31-1.62), thyroid (SIR 1.83, 95% CI 1.32-2.54), colorectal (SIR 1.23, 95% CI 1.14-1.31]), skin melanoma (SIR 1.40, 95% CI 1.11-1.76), and non-melanoma skin (SIR 1.14, 95% CI 1.05-1.23) cancer was observed. For females with T2DM, a significant increase in risk of cancer of the liver (SIR 1.45, 95% CI 1.17-1.79), pancreas (SIR 1.74, 95% CI 1.56-1.93), kidney (SIR = 1.43, 95% CI 1.28-1.60), thyroid (SIR = 1.40, 95% CI 1.22-1.62), breast (SIR = 1.24, 95% CI 1.17-1.31), and corpus uteri (SIR 2.07, 95% CI 1.93-2.21) was observed. In conclusion, people with T2DM in Lithuania had an increased risk of site-specific cancer.

Diabetes and kidney cancer survival in patients undergoing nephrectomy: A Canadian multi-center, propensity score analysis

INTRODUCTION

Diabetes has been associated with worse survival outcomes in various malignancies; however, there are conflicting data in kidney cancer. Determining whether diabetes is associated with survival in kidney cancer may help guide treatment in a comorbid patient population.

METHODS

We used the Canadian Kidney Cancer information system database to identify patients undergoing partial or radical nephrectomy between 1989 and 2017 for localized renal cell carcinoma at 16 institutions across Canada. We derived inverse probability of treatment weights (IPTW) from a propensity score model based on various clinical, surgical, and pathological characteristics. We used Cox proportional hazard models to evaluate the association between diabetes and cancer-specific and overall survival, in the sample weighted by the IPTW.

RESULTS

4828 patients met inclusion criteria, of whom 948 (19.6%) were diabetic. Median follow-up in those without death was 26.6 months (interquartile range 9.7-53.8). Among the entire cohort, 901 deaths were from any cause, and 299 deaths from kidney cancer. Before propensity score methods, diabetics were older, more likely to have comorbidities and clear cell histopathology. After propensity score adjustment, all characteristics were balanced between groups (standardized difference <0.10). IPTW-adjusted Cox proportional hazard models demonstrated no significant association between diabetes and cancer-specific (hazard ratio 1.13, 95% confidence interval 0.78-1.62), or overall survival (hazard ratio 1.14, 95% confidence interval 0.94-1.38).

CONCLUSIONS

Our multi-centre study found that diabetes and nondiabetics have similar survival following nephrectomy for kidney cancer.

Impact of diabetes mellitus on the prognostic value of the neutrophil-lymphocyte ratio in renal cell carcinoma

The aim of the present study was to evaluate the effect of diabetes mellitus (DM) on the neutrophil-lymphocyte ratio (NLR)-based prediction of the prognosis of patients with renal cell carcinoma (RCC). The data of 662 patients who had undergone nephrectomy for RCC between January 2004 and July 2014 were retrospectively reviewed. X-tile analysis was used to determine the optimal cutoff value for the NLR. Kaplan-Meier curves were drawn and the log-rank test was applied to determine the impact of the NLR (high vs. low) on the overall survival (OS) and metastasis-free survival (MFS). Univariate and multivariate Cox regression analyses were used to identify prognostic factors for OS and MFS. The median follow-up period after surgery was 50.35 months (range, 30.30–85.08 months). The optimal cutoff value of the NLR was determined to be 3.2 using X-tile software. In the analysis of total subjects, patients with a high NLR (≥3.2) had significantly worse OS and MFS rates than those with a low NLR (<3.2) (21.60% vs. 78.40%, P=0.001 for OS and 21.60% vs. 78.40%, P<0.0001 for MFS). In the non-DM subgroup, the OS and MFS rates of patients with a high NLR were significantly worse compared with those of patients with a low NLR (21.69% vs. 78.31%, P=0.003 for OS and 21.69% vs. 78.31%, P<0.001 for MFS). In the DM subgroup, although a high NLR was still associated with the MFS (NLR≥3.2, 21.43% vs. NLR<3.2, 78.57%; P=0.015), it was no longer associated with the OS (NLR≥3.2, 21.43% vs. NLR<3.2, 78.57%; P=0.192). Furthermore, multivariate analysis identified the NLR as a risk factor for OS and MFS in all patients [hazard ratio (HR)=1.77, 95% confidence interval (CI): 1.04–3.01, P=0.037; and HR=2.31, 95% CI: 1.45–3.70, P<0.001, respectively) and in the non-DM subgroup (HR=2.03, 95% CI: 1.05–3.93, P=0.036; and HR=2.57, 95% CI: 1.47–4.49, P=0.001, respectively), but not in the DM subgroup (P>0.05). In conclusion, DM is a factor that impairs the evaluation of the prognosis of RCC using NLR.

Role of DNA repair genes XRCC3 and XRCC1 in predisposition to type 2 diabetes mellitus and diabetic nephropathy

INTRODUCTION

Increasing number of experimental and clinical studies suggest a strong relationship between hyperglycemia, oxidative stress, DNA damage and diabetic nephropathy (DN). Also, epidemiologic studies remark an enhanced risk of cancer with type 2 diabetes. This research aims to assess whether the X-ray cross complementing group 3 (XRCC3) gene T241M polymorphism (rs861539) and X-ray cross complementing group 1 (XRCC1) gene A399G polymorphism (rs25487) are related with predisposition to type 2 diabetes mellitus (T2DM) and to diabetic nephropathy in Turkish population.

MATERIALS AND METHODS

Polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP) was performed to identify the distribution of genotypes and frequency of alleles of T241M polymorphism of the XRCC3 gene (XRCC3 T241M) and A399G polymorphism of the XRCC1 gene (XRCC1 A399G). The study population included 238 subjects residing in Istanbul, Turkey; 116 with T2DM, 50 with DN and 72 with normal glucose metabolism.

RESULTS AND CONCLUSION

Polymorphic Gln allele of XRCC1 gene was significantly related with T2DM and DN (OR 3.09, 95% CI 1.14-8.40 and OR 3.29 95% CI 1.23-8.80, respectively) however, there was no statistical association of XRCC3 T241M with T2DM or DN. The results of this study suggest that XRCC1 399Gln polymorphism is related with an increased susceptibility to T2DM and DN in the studied Turkish population.

Sex differences in the association between diabetes and cancer: a systematic review and meta-analysis of 121 cohorts including 20 million individuals and one million events

AIMS/HYPOTHESIS

Diabetes has been shown to be a risk factor for some cancers. Whether diabetes confers the same excess risk of cancer, overall and by site, in women and men is unknown.

METHODS

A systematic search was performed in PubMed for cohort studies published up to December 2016. Selected studies reported sex-specific relative risk (RR) estimates for the association between diabetes and cancer adjusted at least for age in both sexes. Random-effects meta-analyses with inverse-variance weighting were used to obtain pooled sex-specific RRs and women-to-men ratios of RRs (RRRs) for all-site and site-specific cancers.

RESULTS

Data on all-site cancer events (incident or fatal only) were available from 121 cohorts (19,239,302 individuals; 1,082,592 events). The pooled adjusted RR for all-site cancer associated with diabetes was 1.27 (95% CI 1.21, 1.32) in women and 1.19 (1.13, 1.25) in men. Women with diabetes had ~6% greater risk compared with men with diabetes (the pooled RRR was 1.06, 95% CI 1.03, 1.09). Corresponding pooled RRRs were 1.10 (1.07, 1.13) for all-site cancer incidence and 1.03 (0.99, 1.06) for all-site cancer mortality. Diabetes also conferred a significantly greater RR in women than men for oral, stomach and kidney cancer, and for leukaemia, but a lower RR for liver cancer.

CONCLUSIONS/INTERPRETATION

Diabetes is a risk factor for all-site cancer for both women and men, but the excess risk of cancer associated with diabetes is slightly greater for women than men. The direction and magnitude of sex differences varies by location of the cancer.

Cancer incidence among Finnish people with type 2 diabetes during 1989-2014

Diabetes and cancer are common diseases both with enormous impact on health burden globally. The increased risk of several types of cancer among people with type 2 diabetes mellitus has been indicated repeatedly. This study aimed at exploring and describing the association between type 2 diabetes and cancer incidence. A cohort of 428,326 people with type 2 diabetes was identified from the Finnish National Diabetes Register and followed up through a register linkage with the Finnish Cancer Registry for cancer incidence during 1988-2014. A total of 74,063 cases of cancer occurred in this cohort in 4.48 million person-years. This accounted for 16% more than the expected cancer incidence in the Finnish general population; the standardized incidence ratio (SIR) was 1.16 (95% confidence interval [CI] 1.15-1.16). There was a statistically significant excess of cancers of lip (SIR = 1.40, CI = 1.28-1.53), liver (SIR = 2.44, CI = 2.35-2.53), pancreas (SIR = 1.75, CI = 1.70-1.79), stomach (SIR = 1.22, CI = 1.18-1.26), colon (SIR = 1.22, CI = 1.19-1.25), gallbladder and bile ducts (SIR = 1.29, CI = 1.21-1.36), non-melanoma skin (SIR = 1.18, CI = 1.15-1.22), kidney (SIR = 1.42, CI = 1.37-1.47), bladder (SIR = 1.17, CI = 1.13-1.21), and thyroid (SIR = 1.22, CI = 1.12-1.31). There was a small statistically significant decrease in prostate cancer incidence (SIR = 0.95, CI = 0.93-0.96). This study showed an association between type 2 diabetes mellitus and the incidence of cancer at numerous sites in the Finnish population.

Epidemiology and screening for renal cancer

PURPOSE

The widespread use of abdominal imaging has affected the epidemiology of renal cell carcinoma (RCC). Despite this, over 25% of individuals with RCC have evidence of metastases at presentation. Screening for RCC has the potential to downstage the disease.

METHODS

We performed a literature review on the epidemiology of RCC and evidence base regarding screening. Furthermore, contemporary RCC epidemiology data was obtained for the United Kingdom and trends in age-standardised rates of incidence and mortality were analysed by annual percentage change statistics and joinpoint regression.

RESULTS

The incidence of RCC in the UK increased by 3.1% annually from 1993 through 2014. Urinary dipstick is an inadequate screening tool due to low sensitivity and specificity. It is unlikely that CT would be recommended for population screening due to cost, radiation dose and increased potential for other incidental findings. Screening ultrasound has a sensitivity and specificity of 82-83% and 98-99%, respectively; however, accuracy is dependent on tumour size. No clinically validated urinary nor serum biomarkers have been identified. Major barriers to population screening include the relatively low prevalence of the disease, the potential for false positives and over-diagnosis of slow-growing RCCs. Individual patient risk-stratification based on a combination of risk factors may improve screening efficiency and minimise harms by identifying a group at high risk of RCC.

CONCLUSION

The incidence of RCC is increasing. The optimal screening modality and target population remain to be elucidated. An analysis of the benefits and harms of screening for patients and society is warranted.

Epidemiological dimensions of the association between type 2 diabetes and cancer: A review of observational studies

Type 2 diabetes (T2D) is a major cause of complications and death in many countries. The possible causal relation between T2D and cancer has been the aim of many research investigations. In view of the importance of the topic we carried out a narrative review of observational studies to summarize the available evidence of the association between T2D and cancer. To deal with the problem of abundance of published studies, we reviewed up to December 2017, the literature of meta-analyses of observational studies first, then we reviewed cohort studies not reported in meta-analyses because of more recent publication. We found that the association of T2D with risk of colorectal cancer was robust, whereas the evidence of the associations with other cancer sites was lower. Some of the observed associations could be overestimated, due to publication bias, unmeasured confounders (such as obesity) and surveillance bias. In conclusion a probable causal association of T2D with risk of colorectal cancer was confirmed. A possible causal association with pancreatic, endometrial, hepatocellular and gallbladder carcinoma was also found. Substantial uncertainty exists for other cancer sites.

Diabetes induces fibrotic changes in the lung through the activation of TGF-β signaling pathways

In the long term, diabetes profoundly affects multiple organs, such as the kidney, heart, brain, liver, and eyes. The gradual loss of function in these vital organs contributes to mortality. Nonetheless, the effects of diabetes on the lung tissue are not well understood. Clinical and experimental data from our studies revealed that diabetes induces inflammatory and fibrotic changes in the lung. These changes were mediated by TGF-β-activated epithelial-to-mesenchymal transition (EMT) signaling pathways. Our studies also found that glucose restriction promoted mesenchymal-to-epithelial transition (MET) and substantially reversed inflammatory and fibrotic changes, suggesting that diabetes-induced EMT was mediated in part by the effects of hyperglycemia. Additionally, the persistent exposure of diabetic cells to high glucose concentrations (25 mM) promoted the upregulation of caveolin-1, N-cadherin, SIRT3, SIRT7 and lactate levels, suggesting that long-term diabetes may promote cell proliferation. Taken together, our results demonstrate for the first time that diabetes induces fibrotic changes in the lung via TGF-β1-activated EMT pathways and that elevated SMAD7 partially protects the lung during the initial stages of diabetes. These findings have implications for the management of patients with diabetes.

Type 2 Diabetes in Relation to the Risk of Renal Cell Carcinoma Among Men and Women in Two Large Prospective Cohort Studies

OBJECTIVE

We assessed whether type 2 diabetes is associated with renal cell carcinoma (RCC), independent of key potential confounders, in two large prospective cohorts with biennially updated covariate data.

RESEARCH DESIGN AND METHODS

A total of 117,570 women from the Nurses' Health Study (NHS) and 48,866 men from the Health Professionals Follow-Up Study (HPFS) were followed from 1976 and 1986, respectively, through 2014. Multivariable Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% CIs for associations between type 2 diabetes and pathology-confirmed RCC, overall and by stage, grade, and histologic subtype.

RESULTS

During 38 years of follow-up in the NHS, we confirmed 418 RCC case subjects, including 120 fatal cases. Over 28 years in the HPFS, we confirmed 302 RCC case subjects, including 87 fatal cases. Women with type 2 diabetes had a significantly increased risk of RCC compared with women without type 2 diabetes (multivariable HR 1.53; 95% CI 1.14-2.04), with some evidence that the association was stronger for ≤5 (HR 2.15; 95% CI 1.44-3.23) than >5 (HR 1.22; 95% CI 0.84-1.78) years' duration of type 2 diabetes (P_difference 0.03). Among men, type 2 diabetes was not associated with total RCC (HR 0.89; 95% CI 0.56-1.41) or with RCC defined by stage, grade, or subtype. Sample sizes for analyses by stage, grade, and subtype were limited.

CONCLUSIONS

We found that type 2 diabetes was independently associated with a greater risk of RCC in women but not in men.

Sex Differences in the Burden and Complications of Diabetes

PURPOSE OF THE REVIEW

To review the latest evidence on sex differences in the burden and complications of diabetes and discuss the potential explanations for the sex differences described.

RECENT FINDINGS

Diabetes is a strong risk factor for vascular disease, with compelling evidence that the relative risks of vascular diseases conferred by diabetes are considerably greater in women than men. The mechanisms underpinning women's excess relative risk of vascular disease from diabetes are unknown. Sex differences in the health care provided for the prevention, management, and treatment of diabetes and its complications could contribute to women's greater excess relative risks of diabetes complications. However, since the excess risk of vascular disease is not seen for other major vascular risk factors, inherent biological factors may be more likely to be involved. In addition to other cardiometabolic pathways, the sex dimorphism in body composition and fat distribution may be particularly important in explaining women's greater excess risk of the vascular complications of diabetes. There is strong evidence to suggest that diabetes is a stronger risk factor for vascular disease in women than men. Although several mechanisms may be involved, further research is needed to provide new and deeper insights into the mechanisms underpinning sex differences in the association between diabetes and vascular diseases. Such research will inform patients, health care professionals, and policy makers to ensure that women are not disproportionately affected by diabetes, and will help to reduce the burden in both sexes.

Diabetes mellitus and the risk of gastrointestinal cancer in women compared with men: a meta-analysis of cohort studies

Background

The increasing epidemic proportions of diabetes mellitus (DM) are a major cause of premature illness and death. However, whether DM confers the same excess risk of gastrointestinal cancer for women as it does for men remains controversial. The purpose of this study was to estimate the relation between DM and gastrointestinal cancer in women compared with men after accounting for other major risk factors based on cohort studies.

Methods

We performed a meta-analysis of cohort studies published through May 2017 from PubMed, Embase, and the Cochrane Library. Studies with cohort designs were stratified by sex and reported the relation between DM and esophageal cancer (EC), gastric cancer (GC), colorectal cancer (CRC), colon cancer (CC), rectal cancer (RC), hepatocellular carcinoma (HCC), or pancreatic cancer (PC) risk. The ratio of relative risk (RRR) between men and women was employed to measure the sex differences in the relation between DM and gastrointestinal cancer with a random effects model with inverse variance weighting.

Results

We included 38 cohort studies reporting data on 18,060,698 individuals. The pooled RRR indicated DM women was associated with an increased risk of GC (RRR: 1.14; 95%CI: 1.06–1.22; p < 0.001), while the risk of HCC was lower (RRR: 0.88; 95%CI: 0.79–0.99; p = 0.031) as compared with DM men. Further, there was no evidence of sex differences in the RRR between participants who had DM compared with those without DM for EC (p = 0.068), CRC (p = 0.618), and PC (p = 0.976). In addition, the pooled RRR showed a statistically significant association between DM and the risk of CC in women compared with men (RRR: 0.93; 95%CI: 0.86–1.00; p = 0.050), and there was no evidence of sex differences for RC among participants with DM compared to those without DM (p = 0.648). Finally, the sex differences of the comparison between DM and non-DM for gastrointestinal cancer risk at different sites were variable after stratification for different effect estimates.

Conclusions

The findings of this study suggested female-to-male RRR of DM was increased for GC, while reduced for HCC and CC. However, there were no sex differences for the relation between DM and the risk of EC, CRC, PC, and RC.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4351-4) contains supplementary material, which is available to authorized users.

Consumption of fruits and vegetables and risk of renal cell carcinoma: a meta-analysis of observational studies

Background

There have been inconsistent results about the association between consumption of fruits and vegetables and renal cell carcinoma (RCC) risk. We conducted a meta-analysis of the published observational studies to explore this association.

Results

Nineteen observational studies (4 cohort, 1 pooled and 14 case-control studies), involving 10,215 subjects with RCC were part of this meta-analysis. The SRR for the highest vs. the lowest intake of vegetables was 0.73 (95% CI: 0.63–0.85; P_{heterogeneity} = 0.004, I² = 53.5%), whereas for fruits it was 0.86 (95% CI: 0.75–0.98; P_{heterogeneity} = 0.012, I² = 47.4%). Linear dose-response analysis also showed similar results, e.g., for per 1 serving/day increment of vegetables, the SRR was 0.90 (95% CI: 0.84–0.96) and for fruits it was 0.97 (95% CI: 0.93–1.01). Nonlinear association was only observed for vegetables (P_nonlinearity = 0.001), but not for fruits (P_nonlinearity = 0.221).

Materials and Methods

Eligible studies up to August 31, 2016 were identified and retrieved by searching MEDLINE and EMBASE databases along with manual review of the reference list from the retrieved studies. Quality of included studies was evaluated using Newcastle-Ottawa Quality Assessment Scale (NOS). Random-effects model was used to calculate summary relative risk (SRR) and corresponding 95% confidence interval (CI).

Conclusions

This meta-analysis indicated a protective effect of consumption of vegetables and fruits on RCC risk. Further studies are warranted with prospective designs that use validated questionnaires and control for important confounders.

Association of daytime napping with prediabetes and diabetes in a Chinese population: Results from the baseline survey of the China Health and Retirement Longitudinal Study

BACKGROUND

Only a few studies have investigated the effects of daytime napping on diabetes, and these studies have reported conflicting results. The aim of the present study was to examine whether daytime napping is associated with a higher risk of prediabetes and diabetes.

METHODS

The present cross-sectional study of napping duration in relation to prediabetes and diabetes was conducted in 12 277 participants. Data from the first wave (2011) of the China Health and Retirement Longitudinal Study were used. Daytime napping was divided into four groups: no napping (reference) and napping for 1-30, 31-90, and >90 min. Multinomial logistic regression was used to obtain odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Individuals who reported taking daily afternoon naps accounted for 53.39% of all participants. Nappers had a higher prevalence of prediabetes and diabetes than non-nappers. Compared with the reference group, the weighted fully adjusted ORs (95% CI) were 1.36 (1.10-1.68) and 1.61 (1.22-2.13) for napping >90 min in prediabetic and diabetic patients, respectively.

CONCLUSIONS

Long daytime napping duration was positively associated with prediabetes and diabetes. Further physiological and cohort studies are needed to confirm these results and elucidate potential mechanisms.

Diabetes in midlife and risk of cancer in late life: A nationwide Swedish twin study

The association between diabetes and cancer risk remains controversial. Hence, we examined whether midlife diabetes is related to the risk of cancer in late-life, and whether genetic and early-life environmental factors play a role in this association. This study included 25,154 twin individuals born in 1958 or earlier from the Swedish Twin Registry. Information on cancer diagnosis in late life (aged ≥ 65) during 1998-2014, was derived from the National Patient and Cancer Registries. Diabetes was ascertained based on self- or informant-reported history, patient registry and antidiabetic medication use. Midlife diabetes was defined when diabetes was diagnosed before 65 years. Data were analyzed following two strategies: (i) unmatched case-control analysis for all participants using generalized estimating equation (GEE) models, and (ii) co-twin control analysis for cancer-discordant twin pairs using conditional logistic regression. Overall, 1,766 (7.0%) had midlife diabetes and 5,293 (21.0%) had cancer in late-life. In multiadjusted GEE models, the odds ratios (95% CIs) of diabetes were 10.55 (2.95-37.67) for pharynx cancer, 5.78 (1.72-19.40) for small intestine cancer, 2.37 (1.14-4.91) for liver cancer and 0.48 (0.35-0.67) for prostate cancer. In people with diabetes, diabetes duration was dose-dependently associated with cancer risk. In conditional logistic regression analysis of 176 prostate cancer-discordant twin pairs, the association between midlife diabetes and prostate cancer in later life became stronger. Midlife diabetes increases the risk of pharynx, small intestine and liver cancers, but reduces prostate cancer risk in late life. Genetic and early-life environmental factors may partially contribute to the diabetes-prostate cancer association.

Association of body mass index with mortality and postoperative survival in renal cell cancer patients, a meta-analysis

Obesity is one of the major risk factors of cancer. However, how body mass index (BMI) influences the prognosis of renal cell cancer (RCC) patient is unclear. In this work, we have performed a meta-analysis to elucidate the role of abnormal weight in RCC mortality and postoperative survival. Articles related to BMI and RCC mortality as well as postoperative survival has been identified by searching PUBMED and ENBASE. Totally, 19 articles have been selected for this meta-analysis, 5 articles for RCC mortality and 14 for postoperative survival. Compared to normal weight, the estimated relative risks of RCC mortality are 0.71 (95% CI: 0.34–1.49), 1.19 (95% CI: 1.05–1.35) and 1.71 (95% CI: 1.27–2.00) respectively for the underweight, overweight and obesity patients. The risk of RCC mortality increase 5% for each 1 kg/m² increment of BMI. However, the estimated hazard ratios of cancer specific postoperative survival are 2.62 (95% CI: 1.67–4.11), 0.72 (95% CI: 0.63–0.83) and 0.66 (95% CI: 0.49–0.89) respectively for underweight, overweight and obesity RCC patients. The risk of hazard ratio decrease 5% for each 1 kg/m² increment of BMI. In addition, the hazard ratios of postoperative overall survival show a similar tendency. These results indicate an opposite association of BMI with mortality and postoperative survival in renal cell cancer patients.

Differences in risk factors of malignancy between men and women with type 2 diabetes: A retrospective case-control study

BACKGROUND

The aim of this multicenter, retrospective, case-control study was to identify differences in risk factors of malignancy between men and women with type 2 diabetes.

RESULTS

Among women the most prevalent malignancies were: breast and uterine cancers (35.6% and 14.4% respectively), while among men there were: colorectal and prostate cancers (24.5% and 13.3% respectively). In both gender metformin use was associated with lower cancer risk. Obesity and insulin treatment in dose-dependent and time-varying manner were associated with significantly increased risk of malignancy in females. In men, unexpectedly, cardiovascular disease was more prevalent in control group. Other variables did not show significant association with malignancy risk.

MATERIALS AND METHODS

118 women and 98 men with type 2 diabetes mellitus who developed cancer after diagnosis of diabetes and the same number of strictly age matched controls with type 2 diabetes and without malignancy were included into the study. Diabetes duration, antidiabetic medications use, glycated hemoglobin level, body mass index, smoking habits, occupation, presence of comorbidities and aspirin use were included into analyses.

CONCLUSIONS

Metformin demonstrated protective effect against cancer in both sexes. Obesity and insulin treatment seem to have greater impact on cancer risk among women.

Diabetes as a risk factor of hospitalization in the surgical ward due to cancer in the elderly and middle-aged population

INTRODUCTION

Diabetes can be considered as a risk factor of several types of malignancy. Surgery is one of the primary methods of cancer treatment. The objective of this study was to evaluate the association between diabetes and hospital admissions to the surgery unit due to malignancy among elderly and middle-aged people.

MATERIAL AND METHODS

Data for analysis were taken from the medical records of 7,694 patients aged > 45, hospitalized in the General Surgery Ward in the Specialist District Hospital in Stalowa Wola in the Subcarpathian (Podkarpacie) Province, Poland, in the years 2010-2013. Among them malignancy was diagnosed in 652 patients and diabetes in 370 subjects. Ninety-three patients suffered from both diabetes and cancer.

RESULTS

Diabetes was associated with significantly elevated risk of hospitalization due to malignancy compared with the non-diabetic population, odds ratio (OR) 4.051 (95% confidence interval: 3.154-5.203), p < 0.001. Among people with diabetes, elderly patients (> 65 years) had higher risk of hospital admission due to cancer compared with the middle-aged population, OR = 5.238 (2.873-9.550), p < 0.001. Also, urban residents had higher risk compared with rural inhabitants, OR = 2.272 (1.375-3.752), p = 0.002.

CONCLUSIONS

Patients with diabetes, especially elderly and urban inhabitants, are at high risk of hospital admission due to malignancy. This indicates the need for oncological vigilance in such patients for early detection and treatment of cancers common in this population.

Association between type 2 diabetes and risk of cancer mortality: a pooled analysis of over 771,000 individuals in the Asia Cohort Consortium

AIMS/HYPOTHESIS

The aims of the study were to evaluate the association between type 2 diabetes and the risk of death from any cancer and specific cancers in East and South Asians.

METHODS

Pooled analyses were conducted of 19 prospective population-based cohorts included in the Asia Cohort Consortium, comprising data from 658,611 East Asians and 112,686 South Asians. HRs were used to compare individuals with diabetes at baseline with those without diabetes for the risk of death from any cancer and from site-specific cancers, including cancers of the oesophagus, stomach, colorectum, colon, rectum, liver, bile duct, pancreas, lung, breast, endometrium, cervix, ovary, prostate, bladder, kidney and thyroid, as well as lymphoma and leukaemia.

RESULTS

During a mean follow-up of 12.7 years, 37,343 cancer deaths (36,667 in East Asians and 676 in South Asians) were identified. Baseline diabetes status was statistically significantly associated with an increased risk of death from any cancer (HR 1.26; 95% CI 1.21, 1.31). Significant positive associations with diabetes were observed for cancers of the colorectum (HR 1.41; 95% CI 1.26, 1.57), liver (HR 2.05; 95% CI 1.77, 2.38), bile duct (HR 1.41; 95% CI 1.04, 1.92), gallbladder (HR 1.33; 95% CI 1.10, 1.61), pancreas (HR 1.53; 95% CI 1.32, 1.77), breast (HR 1.72; 95% CI 1.34, 2.19), endometrium (HR 2.73; 95% CI 1.53, 4.85), ovary (HR 1.60; 95% CI 1.06, 2.42), prostate (HR 1.41; 95% CI 1.09, 1.82), kidney (HR 1.84; 95% CI 1.28, 2.64) and thyroid (HR 1.99; 95% CI 1.03, 3.86), as well as lymphoma (HR 1.39; 95% CI 1.04, 1.86). Diabetes was not statistically significantly associated with the risk of death from leukaemia and cancers of the bladder, cervix, oesophagus, stomach and lung.

CONCLUSIONS/INTERPRETATION

Diabetes was associated with a 26% increased risk of death from any cancer in Asians. The pattern of associations with specific cancers suggests the need for better control (prevention, detection, management) of the growing epidemic of diabetes (as well as obesity), in order to reduce cancer mortality.

Association between diabetes mellitus and subsequent ovarian cancer in women: A systematic review and meta-analysis of cohort studies

Epidemiologic studies have suggested that diabetes mellitus (DM) might be associated with risk of ovarian cancer; however, the results have been inconsistent. The aim of this study was to determine the relationship between DM and the incidence of ovarian cancer on the basis of cohort studies.Relevant studies from PubMed, Embase, and the Cochrane Library until September 2016 were collected. The summary risk ratio (RR) was used as the effect measure in a random effects model. Sensitivity analysis, subgroup analysis, and calculation of publication bias were conducted.Thirteen articles including 14 cohorts comprising a total of 3708, 313 women and reporting 5534 cases of ovarian cancer were included. The summary RR suggested that patients with DM had a higher risk of ovarian cancer than patients without DM (RR: 1.19; 95% confidence interval: 1.06-1.34; P = .004), and no evidence of publication bias was found. The subgroup analysis indicated a higher incidence of ovarian cancer in patients with DM in studies published after 2010, studies not conducted in Europe or the United States, studies that did not adjust for body mass index or smoking status, and studies with lower Newcastle-Ottawa Scale scores.The present findings indicated that DM is a risk factor for ovarian cancer, and future large-scale epidemiologic studies should be performed to evaluate this relation in specific populations.

Diabetes and kidney cancer outcomes: a propensity score analysis

There is conflicting evidence whether diabetes is associated with survival outcomes in patients undergoing a nephrectomy for renal cell carcinoma. We performed a retrospective review of 1034 patients undergoing nephrectomy for unilateral, M0, renal cell carcinoma between 2000 and 2016 at a tertiary academic center. Inverse probability of treatment weights were derived from a propensity score model based on various clinical, surgical, and pathological characteristics. We used Cox proportional hazard models to evaluate the association between diabetes and disease-free survival, cancer-specific survival, and overall survival in the sample weighted by the inverse probability of treatment weights. Furthermore, to evaluate whether severity of diabetes was associated with survival outcomes, we performed separate analyses where inverse probability of treatment weights were computed based on the probability of having diabetes that was controlled by medication. Of the 1034 patients, 180 (17 %) had diabetes. Of these, 139 (77 %) patients required medications for diabetes control while the remaining 41 (23 %) had diet controlled diabetes. Median follow-up was 50 months (IQR 17-86). Diabetes at the time of surgery was not significantly associated with disease-free survival (HR 1.11, 95 % CI 0.64 -1.91), cancer-specific survival (HR 0.96, 95 % CI 0.49-1.91), or overall survival (HR 1.28, 95 % CI 0.84-1.95). We found similar results when we compared diabetics controlled with medication vs. non-diabetics or diet controlled diabetics. In summary, we found no significant association between diabetes and survival outcomes in patients undergoing nephrectomy for M0 renal cell carcinoma. These results suggest that diabetics should be treated and followed in a similar manner to non-diabetics.