Cancer in patients admitted to hospital with diabetes mellitus aged 30 years and over: record linkage studies

Role of Insulin Use and Social Determinants of Health on Non-melanoma Skin Cancer: Results From the Behavioral Risk Factor Surveillance System

BACKGROUND

Non-melanoma skin cancer (NMSC) is a frequent type of malignancy with a steadily increasing incidence rate worldwide. Although NMSC was shown to be associated with diabetes, no studies have addressed the extent to which insulin use influences the risk of NMSC in light of social determinants of health (SDOH). We conducted a quantitative study that examined the interplay between insulin use, SDOH, additional covariates, and NMSC among individuals with diabetes.

METHODS

We based our analysis on the 2020 Behavioral Risk Factor Surveillance System (BRFSS), a national survey conducted yearly in the US. We performed weighted chi-squared test, logistic regression, and survival analyses on 8685 eligible participants with diabetes enrolled in the BRFSS.

RESULTS

Kaplan Meier survival curves showed higher probability of NMSC event-free survival for participants with diabetes using insulin compared to participants with diabetes not using insulin (log-rank test P < .001). Significant associations were detected between insulin use and reduced odds of NMSC (OR .56; 95% CI: .38-.82), and decreased hazard (HR .36; 95% CI: .21-.62), along with indices of SDOH.

CONCLUSIONS

Our findings suggest that socioeconomic differences related to the healthcare system and behavioral patterns are linked to discrepancies in the use of insulin and the development of NMSC.

Hospital admissions among people with diabetes: A systematic review

OBJECTIVE

To describe the reasons for hospital admission among people with diabetes.

METHODS

We searched Emcare, Embase, Medline and Google Scholar databases for population-based studies describing the causes of hospitalisation among people with diabetes. We included articles published in English from 1980 to 2022. For each study, we determined the most frequent reasons for admission. Studies were assessed for quality using the Newcastle Ottawa quality assessment tool.

RESULTS

6920 research articles were retrieved from the search of all sources. After screening the titles and abstracts of these, we reviewed the full text of 135 papers and finally included data from 42 studies. Admissions among the total diabetes were reported in 25 papers: 5 articles reported type 1 diabetes alone, 10 articles reported type 2 diabetes alone and the remaining 2 articles reported type 1 and type 2 diabetes separately. Among the 25 total and type 2 diabetes studies that reported the distribution of hospitalisations in broad categories, cardiovascular diseases (CVD) were the leading cause of admission in 19/25 (76%) of studies. Among the 19 studies that reported CVD admissions by subcategories, ischaemic or coronary heart disease was the leading subtype of CVD in 58% of studies. The other common causes of admissions were infections, renal disorders, endocrine, nutritional, metabolic and immunity disorders. In people with type 1 diabetes, acute diabetes complications were the leading cause of admission.

CONCLUSION

CVD are the leading cause of hospital admission for people with diabetes, with ischaemic or coronary heart disease as the predominant subtype.

Total Prostate Specific Antigen in Prostate Cancer Screening in Hyperglycemic Individuals

AIM

In this study, it was aimed to investigate the reliability of total prostate-specific antigen (t-PSA) in prostate cancer screening in hyperglycemic (≥126 mg/dL) individuals.

METHODS

This research was planned as a cross-sectional retrospective study. Three hundred eleven cases which underwent biopsy with the suspicion of prostate cancer in the hospital were included in the study. Prostate cancer risk groups were categorized as low, intermediate and high. Those with fasting blood glucose (FBG) levels lower than 126 mg/dL were considered as the normoglycemia group.

RESULTS

It was determined that the t-PSA measurement was higher in the patient group with cancer (P < .001). It was determined that the median t-PSA levels of the intermediate and high cancer groups were higher than the low cancer group (P < .001 and P = .001, respectively). t-PSA was found to be associated with increased cancer risk in cases with FBG <126. However, an increase in t-PSA values in cases with FBG ≥126 was not associated with increased prostate cancer. There is no relationship between FBG measurement and t-PSA measurement (rs=0.05, P = .446). In addition, it was determined that the t-PSA measurements of patients with FBG ≥126 and FBG<126 did not differ (P = .962).

CONCLUSIONS

As a contribution to literature, we found that the t-PSA test lost its sensitivity in cases with plasma glucose levels above normal. Loss of sensitivity may result in underdiagnosis in prostate cancer and this, in turn, results in diagnosis of the cancer at a later stage. In the future, it may be necessary to adopt a different approach in prostate cancer screening in hyperglycemic cases.

Metabolic disorders and the risk of head and neck cancer: a protocol for a systematic review and meta-analysis

INTRODUCTION

Head and neck cancer squamous cell carcinoma (HNSCC) is the sixth most common cancer internationally. Established risk factors include smoking, alcohol and presence of human papillomavirus (HPV). The incidence rate of new disease continues to rise, despite falls in alcohol consumption and a reduction in smoking, the rising rates are unlikely to be solely attributed to HPV status alone. Obesity and its associated conditions such as type 2 diabetes (T2D) are implicated in the risk and progression of a variety of cancers, but there is paucity of evidence regarding its role in HNSCC.

METHODS AND ANALYSIS

A systematic review of cohort studies, reporting a risk of incident HNSCC, will be included. A systematic search strategy has been developed, multiple databases will be searched from January 1966 to November 2021, including Cochrane Library, OVID SP versions of Medline and EMBASE. The primary outcome will be incident HNSCC based on exposures of T2D, obesity, dyslipidaemia and hypertension as defined by the WHO. A combined risk effect across studies will be calculated using meta-analysis, although depending on the heterogeneity in study design, exposure and outcome reporting this may not be possible.

ETHICS AND DISSEMINATION

No ethical approval is required for this systematic review. The review will be published in a relevant peer-review journal and findings will be presented at scientific meetings in both poster and oral presentation form.

PROSPERO REGISTRATION NUMBER DETAILS

This study has been registered with the International Prospective Register of Systematic Reviews (PROSPERO) with study registration number CRD42021250520. This protocol has been developed in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols guidance statement.

Assessing the association of diabetes with lung cancer risk

BACKGROUND

Diabetes is a well-established risk factor for many cancers, but its relationship with lung cancer incidence remains unclear. In this study, we aimed to assess if diabetes is independently associated with lung cancer risk and histology subtype among participants in a screening study.

METHODS

In a retrospective cohort study using data from the Prostate, Lung, Colorectal, and Ovarian (PLCO) study, we assessed the association of self-reported diabetes with lung cancer incidence using Poisson regression while adjusting for other established risk factors in the PLCOM2012, a validated lung cancer prediction model. The adjusted association of diabetes and lung cancer cell type was evaluated using nominal regression. Stratified analyses were also conducted according to sex, smoking history, and body mass index categories.

RESULTS

Overall, 140,395 participants were included in our analysis. Diabetes was not significantly associated with lung cancer incidence [incidence rate ratio (IRR): 1.03, 95% confidence interval (CI): 0.91-1.17]. Similarly, stratified analyses also did not show significant associations between diabetes and lung cancer risk (all P values >0.05). We found no significant difference in the distribution of lung cancer histology in participants with vs. without diabetes (P=0.30).

CONCLUSIONS

Diabetes was not an independent risk factor for lung cancer in a large cohort of PLCO participants. We did not observe differences in histology according to diabetes status. These results suggest that patients with diabetes do not need more aggressive lung cancer screening. Future research including more detailed metabolic parameters may further elucidate the relationship between metabolic disease and lung cancer risk.

Obesity-Independent Association between Glycemic Status and the Risk of Hematologic Malignancy: A Nationwide Population-Based Longitudinal Cohort Study

There have been conflicting results regarding the association between diabetes and the risk of hematologic malignancies, and its interaction with obesity is unknown. This study determined the risk of hematologic malignancies according to the glycemic status in a population-based study involving health screening 9,774,625 participants. The baseline glycemic status of the participants was categorized into no diabetes, impaired fasting glucose (IFG), newly detected diabetes, diabetes duration <5 years, and diabetes duration ≥5 year groups. The risks of overall and specific hematologic malignancies were estimated using a Cox regression analysis. During a median follow up of 7.3 years, 14,733 hematologic malignancies developed. The adjusted hazard ratio (aHR) for the risk of all the hematologic malignancies was 0.99 (95% confidence interval (CI) 0.95-1.02) for IFG, 0.99 (95% CI 0.91-1.08) for newly detected diabetes, 1.03 (95% CI 0.96-1.11) for diabetes duration <5 years, and 1.11 (95% CI 1.03, 1.20) for diabetes duration ≥5 year groups. The association was independent from obesity. The risk of non-Hodgkin's lymphoma (NHL) increased according to the progression of dysglycemia towards a longer diabetes duration, while Hodgkin's lymphoma did not. This study in Korea demonstrated diabetes to be associated with an increased risk of hematologic malignancies independent of obesity. The NHL risk increased with the diabetes duration.

A molecular link between diabetes and breast cancer: Therapeutic potential of repurposing incretin-based therapies for breast cancer

Female breast cancer recently surpassed lung cancer and became the most commonly diagnosed cancer worldwide. As per the recent data from WHO, breast cancer accounts for one out of every 8 cancer cases diagnosed among an estimated 2.3 million new cancer cases. Breast cancer is the most prevailing cancer type among women causing the highest number of cancer-related mortality. It has been estimated that in 2020, 68,5000 women died due to this disease. Breast cancers have varying degrees of molecular heterogeneity; therefore, they are divided into various molecular clinical sub types. Recent reports suggest that type 2 diabetes (one of the common chronic diseases worldwide) is linked to the higher incidence, accelerated progression, and aggressiveness of different cancers; especially breast cancer. Breast cancer is hormone-dependent in nature and has a cross-talk with metabolism. A number of antidiabetic therapies are known to exert beneficial effects on various types of cancers, including breast cancer. However, only a few reports are available on the role of incretin-based antidiabetic therapies in cancer as a whole and in breast cancer in particular. The present review sheds light on the potential of incretin based therapies on breast cancer and explores the plausible underlying mechanisms. Additionally, we have also discussed the sub types of breast cancer as well as the intricate relationship between diabetes and breast cancer.

Type 2 diabetes mellitus and risk of head and neck cancer subtypes: a systematic review and meta-analysis of observational studies

AIMS

The association between type 2 diabetes mellitus (T2DM) and risk of head and neck cancer (HNC) remains unclear. This study aims to perform a system review and meta-analysis to explore this relationship.

METHODS

PubMed, Web of Science, and Embase databases were searched for studies published up to July 31, 2020, regarding the association between T2DM and HNC risk. A random-effects model was utilized to calculate summary relative risks (RRs) with corresponding 95% confidence intervals (CIs).

RESULTS

Fourteen case-control studies and thirteen cohort studies were included in our analysis. We observed a weak association between T2DM and risk of HNC overall, but there was no statistical significance (RR, 1.04; 95% CI, 0.88-1.23; I² = 83.2%). Interestingly, there was a strong association in East Asia (RR, 1.46; 95% CI, 1.21-1.77; I² = 36.6%). For HNC subtypes, T2DM conferred a significantly elevated risk in oral cancer (RR, 1.22; 95% CI, 1.01-1.47; I² = 89.0%). However, in subgroup analyses of smoking, alcohol use, and body mass index (BMI)/obesity adjustments, the association between T2DM and oral cancer risk became insignificant. In addition, T2DM was not associated with a statistically elevated risk of pharyngeal cancer (RR, 1.18; 95% CI, 0.94-1.49; I² = 72.9%) and laryngeal cancer (RR, 1.03; 95% CI, 0.88-1.22; I² = 71.2%).

CONCLUSIONS

This meta-analysis indicates that T2DM is associated with an increased risk of HNC in East Asia. As for site-specific cancer types, the risk of oral cancer was significantly increased in T2DM patients, which appear to be mediated or confounded by smoking, alcohol use, or BMI/obesity.

The association between type 1 and 2 diabetes mellitus and the risk of leukemia: a systematic review and meta-analysis of 18 cohort studies

Diabetes mellitus (DM) is widely considered to be associated with the risk of diverse cancers; however, the association between DM and the risk of leukemia is still controversial. Thus, a detailed meta-analysis of cohort studies was conducted to elucidate this association. Eligible studies were screened through the electronic searches in PubMed, Web of Science, and Embase from their inception to August 11, 2020. Summary relative risks (RRs) and 95% confidence intervals (CIs) were computed through the random-effects model. Eighteen articles involving 10,516 leukemia cases among a total of 4,094,235 diabetic patients were included in this meta-analysis. Overall, twenty-five RRs were synthesized for type 2 diabetes mellitus (T2DM) and yielded a summary RR of 1.33 (95%CI, 1.21-1.47; p < 0.001). For type 1 diabetes mellitus (T1DM), 7 RRs were combined, however, the pooled RR was insignificant (RR, 1.08; 95%CI, 0.87-1.34; p = 0.48). Interestingly, the summary RR for East Asia (RR, 1.83, 95%CI, 1.63-2.06) was significantly higher than that for Europe (RR, 1.11, 95%CI, 1.06-1.15), Western Asia (RR, 1.40, 95%CI, 1.25-1.54), North America (RR, 1.14, 95%CI, 1.08-1.20), and Australia (RR, 1.47, 95%CI, 1.25-1.71). Moreover, we found that patients with a shorter T2DM duration (1-5 years) had a higher risk of leukemia compared to those with a longer duration (5.1-10 years). Overall, this meta-analysis suggests there is a moderately increased risk of leukemia among T2DM patients, but not in T1DM patients. Further investigation is warranted.

Diabetes mellitus and the risk of ovarian cancer: a systematic review and meta-analysis of cohort and case-control studies

OBJECTIVE

Emerging evidence from observational studies (cohort and case-control studies) suggests that a history of diabetes mellitus (DM) has been linked to increased risk of ovarian cancer (OC), but the association between them remains inconclusive. The aim of this systematic review and meta-analysis of observational studies was to clarify this association.

DESIGN

Systematic review and meta-analysis.

METHODS

We searched PubMed, Embase and the Cochrane library databases published from the inception through 9 April 2020 without language restriction. Observational studies that evaluated the correlation between DM and the incidence of OC were included in our study. Relative risk (RR) with 95% CI was pooled by use of a random-effects model.

RESULTS

A total of 36 epidemiological articles, including 9 case-control and 27 cohort studies, were finally enrolled, consisting of 14 496 incident cases of OC. Synthesised RRs of developing OC by history of DM were 1.20 (95% CI=1.10 to 1.31) for all eligible studies, 1.08 (95% CI=0.77 to 1.53) for case-control studies and 1.22 (95% CI=1.11 to 1.33) for cohort studies. The above-mentioned positive association persisted across most of subgroup analyses, whereas it was not significant among studies from North American and European countries, level of unadjusted, and patients with low-quality and gestational DM group. The cumulative meta-analysis and sensitivity analysis showed pooled effect was stable and reliable, and no apparent publication bias was identified in this study.

CONCLUSIONS

Our study found weaker but still association between DM and OC risk. However, further well-designed prospective studies that control for potential confounders are warranted.

Reduced risk of prostate cancer in a cohort of Lithuanian diabetes mellitus patients

BACKGROUND

During the past decade, a huge interest was devoted to the type-2 diabetes mellitus and their associations with prostate cancer development.

OBJECTIVES

The aim of this study was to determine whether type 2 diabetes mellitus and treatment with metformin is associated with prostate cancer risk.

MATERIALS AND METHODS

The cohort was composed of diabetic male patients identified in the National Health Insurance Fund database during 2000-2016 and cancer cases in national Cancer Registry. We calculated standardized incidence ratios (SIR) for prostate cancers as a ratio of observed number of cancer case in people with diagnosis of diabetes to the expected number of cancer cases in the underlying general population.

RESULTS

2754 prostate cancers were observed versus 3111.26 expected within the period of observation entailing an SIR of 0.89 (95% CI: 0.85-0.92). Significantly lower risk of prostate cancer was found in diabetes patients in all age groups, also was in metformin-users and never-users' groups, with higher risk reduction in metformin-users (SIR 0.71, 95% CI: 0.68-0.75) than in diabetes patients never-users (SIR 0.88, 95% CI: 0.80-0.96).

CONCLUSION

In this large population-based study, we found a significantly decreased risk of prostate cancer among men with diabetes and metformin-users.

Incidence of human papillomavirus-related anogenital precancer and cancer in women with diabetes: A nationwide registry-based cohort study

In this register-based cohort study, we estimated the incidence of human papillomavirus (HPV)-related anogenital precancer and cancer in women with diabetes compared with women without diabetes. We followed all women living in Denmark born 1916 to 2001 (n = 2 508 321) for individual-level information on diabetes (Type 1 or 2 [T1D or T2D]), diagnoses of cervical, vaginal, vulvar and anal intraepithelial neoplasia Grade 2 or 3 (IN2/3) and cancer and other covariates from nationwide registries. We used Poisson regression to model the incidence rates of anogenital IN2/3 and cancer as a function of diabetes status, age, HPV vaccination, education, calendar year, and cervical cancer screening status. Incidence rate ratios (IRRs) were estimated for diabetes overall, and separately for T1D and T2D, compared with women without diabetes. Women with diabetes had higher rates of vulvar IN2/3 (IRR = 1.63; 95% confidence interval [CI]: 1.41-1.88), vulvar cancer (IRR = 1.61; 95% CI: 1.36-1.91) and vaginal cancer (IRR = 1.79; 95% CI: 1.27-1.91) than women without diabetes. Similar patterns were observed for anal IN2/3, anal cancer and cervical cancer, although not statistically significant. In contrast, women with diabetes had lower rates of cervical IN2/3 (IRR = 0.74; 95% CI: 0.69-0.79) than women without diabetes. Patterns were generally similar in women with T1D and T2D, although cancer rates were higher in women with T2D. In conclusion, the incidence of most anogenital precancers and cancers were increased in women with diabetes. However, women with diabetes had lower incidence of cervical precancer. Our findings could be explained by biological mechanisms and/or behavioral factors, such as smoking and less frequent cervical screening participation.

Association between diabetes mellitus and lung cancer: Meta-analysis

BACKGROUND

This study aimed to summarize the association between diabetes mellitus (DM) and the incidence of lung cancer using a meta-analysis of cohort studies.

MATERIALS AND METHODS

We systematically searched PubMed, Embase and the Cochrane Library to identify potential cohort studies. Relative risk (RR) was used to calculate the association between DM and the risk of lung cancer. Subgroup analysis, sensitivity analysis and test for publication bias were performed. Twenty cohort studies were selected.

RESULTS

The participants with DM showed little or no significant effect on the risk of lung cancer (RR: 1.10; 95% CI: 0.99-1.23; P = .087). DM was not associated with the risk of lung cancer in men (RR: 1.11; 95%CI: 0.92-1.35; P = .270), but a significant association was observed in women (RR: 1.18; 95%CI: 1.10-1.28; P < .001). Subgroup analysis suggested that smoker status was confounding variables that could bias the relationship between DM and the incidence of lung cancer.

CONCLUSIONS

This meta-analysis suggests that DM has no significant impact on the incidence of lung cancer in men but has a harmful effect on women.

Type 2 diabetes mellitus does not increase the risk of multiple myeloma: a systematic review and meta-analysis

Background

Epidemiological studies have shown that patients with type 2 diabetes mellitus (T2DM) are at a higher risk of secondary tumors. However, no consensus has been made about whether T2DM can increase the risk of multiple myeloma (MM).

Methods

We searched the databases of PubMed, Cochrane Library and EMBASE and cross-checked the bibliography. Data quality was assessed using the Newcastle-Ottawa scale (NOS). Heterogeneity was calculated as the odds ratio (OR) using a random-effects model. Data were analyzed using Stata version 12.0 software.

Results

A total of 13 articles were selected into this meta-analysis. Initially, we found that diabetic patients had a higher risk of myeloma than non-diabetic patients (OR =1.60, 95% CI: 1.13–2.26, I²=98%, P=0.000). But the data in these articles were highly heterogeneous (I²>75%). Therefore, eight of the included articles showed a moderate heterogeneity (I²=71.6%). We used Galbraith heterogeneity map to analyze the causes of heterogeneity. Two articles with high heterogeneity were excluded. Then, we found the heterogeneity of the left six articles was reduced from moderate to mild (I²=45.9%, P=0.100). The final results of this meta-analysis showed that T2DM was not a risk factor for increased incidence of MM (OR =1.05, 95% CI: 0.83–1.33, I²=45.9%, P=0.100). Also, the subgroup analysis (case-control studies vs. cohort studies) showed no statistical difference (OR =1.19, 95% CI: 0.76–1.85, I²=1%, P=0.364; OR =1.00, 95% CI: 0.75–1.33, I²=71.2%, P=0.031; respectively).

Conclusions

T2DM is not a risk factor for the increased incidence of MM, a finding that should be validated with more strictly designed randomized controlled trials (RCTs).

Association of diabetes mellitus with non-Hodgkin lymphoma risk: a meta-analysis of cohort studies

Background: Diabetes mellitus (DM) is considered to be a risk factor in the prognosis of many types of cancer, but the effect of DM on the risk of non-Hodgkin lymphoma (NHL) is still under dispute. We performed this study to examine the association between DM and subsequent NHL risk. Methods: A systematically search had been performed in PubMed, EmBase, and the Cochrane Library to identify eligible studies from inception to September 2018. Results: Thirteen cohort studies were included, with a total of 9024761 participants. The results showed that DM was associated with an increased risk of NHL (RR = 1.15, 95%CI: 1.02, 1.30, P = .03). Subgroup analyses suggested that DM was significantly associated with patients aged less than 60 years old (RR = 1.65, 95%CI: 1.31, 2.09, P < .0001), follow-up duration within 8 years (RR = 1.23, 95%CI: 1.02, 1.48, P = .03), and studies adjusted for body mass index (RR = 1.35, 95%CI: 1.01, 1.79, P = .04). The analyses within DM patients indicated that DM men were more likely to develop NHL than DM women (RR = 1.31, 95%CI: 1.04, 1.65, P = .02). Conclusions: These results indicated that DM patients have significantly increased risk of NHL compared nondiabetics. Male DM patients were more likely to develop NHL compared with female. However, further large-scale studies are required to eliminate miscellaneous factors in all included studies.

Comparison of tumour and serum specific microRNA changes dissecting their role in pancreatic ductal adenocarcinoma: a meta-analysis

Background

Pancreatic ductal adenocarcinoma (PDAC) is considered as one of the most aggressive cancers lacking efficient early detection biomarkers. Circulating miRNAs are now being considered to have potency to be used as diagnostic and prognostic biomarkers in different diseases as well as cancers. In case of cancer, a fraction of the circulating miRNAs is actually derived from the tumour tissue. This fraction would function as stable biomarker for the disease and also would contribute to the understanding of the disease development. There are not many studies exploring this aspect in pancreatic cancer and even there is not much overlap of results between existing studies.

Methods

In order to address that gap, we performed a miRNA microarray analysis to identify differentially expressed circulating miRNAs between PDAC patients and normal healthy individuals and also found two more similar datasets to perform a meta-analysis using a total of 182 PDAC patients and 170 normal, identifying a set of miRNAs significantly altered in patient serum. Next, we found five datasets studying miRNA expression profile in tumour tissues of PDAC patients as compared to normal pancreas and performed a second meta-analysis using data from a total of 183 pancreatic tumour and 47 normal pancreas to detect significantly deregulated miRNAs in pancreatic carcinoma. Comparison of these two lists and subsequent search for their target genes which were also deregulated in PDAC in inverse direction to miRNAs was done followed by investigation of their role in disease development.

Results

We identified 21 miRNAs altered in both pancreatic tumour tissue and serum. While deciphering the functions of their target genes, we characterized key miR-Gene interactions perturbing the biological pathways. We identified important cancer related pathways, pancreas specific pathways, AGE-RAGE signaling, prolactin signaling and insulin resistance signaling pathways among the most affected ones. We also reported the possible involvement of crucial transcription factors in the process.

Conclusions

Our study identified a unique meta-signature of 21 miRNAs capable of explaining pancreatic carcinogenesis and possibly holding the potential to act as biomarker for the disease detection which could be explored further.

Association between type 1 and type 2 diabetes and risk of non-Hodgkin's lymphoma: A meta-analysis of cohort studies

AIM

Diabetes mellitus (DM) is thought to be associated with an increased risk of non-Hodgkin's lymphoma (NHL), although the evidence so far remains inconsistent. Thus, our study aimed to further assess this association.

METHODS

Electronic searches were performed of the PubMed, Web of Science and Embase databases up to 11 March 2019. A random-effects model was used to calculate summary relative risks (RRs) with corresponding 95% confidence intervals (CIs).

RESULTS

A total of 20 articles including data from 35 cohort studies matched our inclusion criteria, and 31 RRs were calculated for type 2 DM; the summary RR was 1.20 (95% CI: 1.12-1.30, I² = 84.7%). Also, four RRs were calculated for type 1 DM, and the result was significant (RR: 1.55, 95% CI: 1.15-2.08, I² = 0.0%). The results of subgroup analyses demonstrated that the association between DM and NHL was much more substantial in an Asian population, while sensitivity analyses suggested the robustness of a positive association between DM and NHL risk. In addition, the RR of NHL correlated negatively with duration of DM, with the highest risk found in patients within 1-2 years of DM diagnosis.

CONCLUSION

Our study findings suggest a moderate increase in risk of NHL in type 1 and 2 DM patients. Future studies should investigate the effects of duration of DM and antidiabetes interventions on NHL risk.

Actinic keratosis and diabetes complications: A nationwide population-based study in South Korea (2009-2015)

AIM

As the associations between actinic keratosis (AK) and diabetes complications in patients with diabetes mellitus (DM) have never been investigated, this study aimed to evaluate any such associations in patients with DM.

METHODS

This retrospective cohort study analyzed clinical data for DM patients aged>40 years who had undergone the health examination recommended by the South Korea National Health Insurance Program between 2009 and 2012 (n=2,056,580). All of these patients were classified according to the presence of diabetic retinopathy (DR), end-stage renal disease (ESRD) and history of DVD; myocardial infarction, stroke, transient ischaemic attacks. Newly diagnosed AK was identified using claims data from baseline to the date of diagnosis or 31 December 2015, whichever came first.

RESULTS

Of the 2,056,580 patients with DM, 6404 (0.31%) developed AK. Those patients in the DR, ESRD and CVD groups were more likely to be diagnosed with AK (P<0.001, by log-rank test). After adjusting for age and gender, the risks for AK were significantly higher in the DR, ESRD and CVD groups: HR (95% CI): 1.29 (1.21-1.39), HR: 4.24 (3.28-5.47) and HR: 1.22 (1.13-1.31), respectively.

CONCLUSION

This study has revealed that the incidence of AK is higher in diabetes patients with ocular, renal and cardiovascular complications.

The association between metabolic syndrome and bladder cancer susceptibility and prognosis: an updated comprehensive evidence synthesis of 95 observational studies involving 97,795,299 subjects

Background

The association between metabolic syndrome (MS) and bladder cancer (BC) was not fully investigated, and most primary studies and pooled analyses were only focused on certain specific components.

Objective

To further investigate this issue and obtain more precise findings, we conducted this updated evidence synthesis of published studies, which involved not only MS components but also the MS in its entirety.

Materials and methods

We searched the PubMed, EMBASE, and Web of Science databases for observational studies on the association between BC susceptibility and/or mortality, and MS and its components. We extracted data from included studies, evaluated heterogeneity, and performed meta-analytic quantitative syntheses.

Results

A total of 95 studies with 97,795,299 subjects were included in the present study. According to the results, MS significantly increased the risk of BC (risk ratio [RR]=1.11, 95% CI=1.00–1.23); diabetes significantly increased the risk of BC (RR=1.29, 95% CI=1.19–1.39) and associated with poor survival (RR=1.24, 95% CI=1.08–1.43). Excessive body weight was associated with increased susceptibility (RR=1.07, 95% CI=1.02–1.12), recurrence (RR=1.46, 95% CI=1.18–1.81), and mortality (RR=1.17, 95% CI=1.00–1.37). As indicated by cumulative meta-analysis, sample size was inadequate for the association between BC susceptibility and MS, the association between BC recurrence and excessive body weight, and the association between BC survival and diabetes. The sample size of the meta-analysis was enough to reach a stable pooled effect for other associations.

Conclusion

Diabetes and excessive body weight as components of MS are associated with increased susceptibility and poor prognosis of BC. Uncertainty remains concerning the impact of overall MS, hypertension, and dyslipidemia on BC susceptibility and prognosis, for which further investigations are needed.

Factors pertaining to long-term mortality following emergency visits for head and neck cancer

Background/purpose

Avoiding mortality has been the ultimate goal in the management of head and neck cancer (HNC) patients with emergency department (ED) visits, however, risk factors and causes of mortality are not well studied. The objective of the present study is to verify the factors associated with long-term mortality of patients with HNC who visited ED.

Materials and methods

We retrospectively collected data of 1660 HNC patients who made ED visits from the Longitudinal Health Insurance Database 2000 during 2000–2012 in Taiwan. The multivariate Cox proportional hazard model was used to measure the mortality-associated risk factors in HNC patients who made ED visits.

Results

The prognostic factors associated with mortality risk were age (≥65 vs. < 65 y; HR = 1.58, p < 0.0001), geographic region (central vs. northern; HR = 1.20, p = 0.0384; southern vs. northern; HR = 1.38, p = 0.0001), surgery (yes vs. no; HR = 0.61, p < 0.0001), radiotherapy (yes vs. no; HR = 1.80, p < 0.0001), chemotherapy (yes vs. no; HR = 1.68, p < 0.0001), acute myocardial infarction (yes vs. no; HR = 2.01, p = 0.0303), diabetes mellitus (yes vs. no; HR = 1.60, p < 0.0001), chronic obstructive pulmonary (yes vs. no; HR = 1.51, p = 0.0002), number of ED visits (≥4 vs. 1; HR = 0.69, p = 0.0003), and number of admissions (1 vs. 0; HR = 1.54, p < 0.0001; ≥2 vs. 0; HR = 1.48, p = 0.0002).

Conclusion

Higher mortality was associated with older age, living in southern Taiwan, not having undergone surgery, having received radiotherapy and chemotherapy, comorbidities, and more hospital admissions. A coordinated and extended multidisciplinary approach including ED care is required to improve the long-term survival and further decrease the economic burden of HNC treatment.

Fatty acid receptor GPR120: a novel marker for human melanoma

The correlation between ultraviolet radiation of the skin and melanoma incidence in humans is well established. Interestingly, epidemiologic data suggest also a correlation to an increased BMI pointing to metabolic trigger factors in melanoma pathogenesis. To substantiate this connection, we studied the expression of G-protein-coupled receptor 120 (GPR120), a receptor sensitive to unsaturated long-chain free fatty acids in melanoma tissues. One-hundred fourteen tissue sections histologically confirmed as nevi (n=32), primary melanoma (n=39), and melanoma metastasis (n=43) were immunohistochemically stained against GPR120. The staining was evaluated by three trained dermatopathologists and independently scored. Compared with nevi, primary melanoma and melanoma metastasis showed significantly higher levels of GPR120 staining. Only three out of 32 nevi showed strong GPR120 expression [median immunoreactivity-scoring system (IRS) score: 1, range: 0-10], whereas in primary melanomas 14 out of 39 were highly GPR120-positive (median IRS score: 7, range: 0-12) and in melanoma metastasis 27 out of 43 were highly GPR120-positive (median IRS score: 9, range: 0-12). GPR120 expression and tumor thickness (mm) show a statistically significant correlation in primary melanoma (P=0.011). Moreover, GPR120-positive staining was found throughout the epidermis and in sebaceous and sweat glands, which is yet not described. This study identified GPR120 as a novel marker for melanoma, indicating that melanoma cells are sensitive to free fatty acids. It is tempting to speculate that pharmacologically interfering with GPR120 signaling might improve melanoma therapy.

Diabetes mellitus and the risk of bladder cancer: A PRISMA-compliant meta-analysis of cohort studies

BACKGROUND

Epidemiologic studies have reported inconsistent results regarding the relationship between diabetes mellitus (DM) and the incidence of bladder cancer. This comprehensive systematic review and meta-analysis explored and evaluated this relationship in participants with different characteristics.

METHODS

Studies indexed in the PubMed, Embase, and the Cochrane Library databases that compared bladder cancer incidence mortality between DM and non-DM participants were included in the present study. The relative risks (RRs) of a random-effects model were used to assess these associations.

RESULTS

The final analysis included 21 cohort studies, involving a total of 13,505,643 participants. Overall, DM was associated with an increased risk of bladder cancer or cancer mortality when compared with non-DM participants (RR: 1.23; 95% confidence interval [CI]: 1.12-1.35; P < .001). Furthermore, DM had a harmful impact on subsequent bladder cancer risk in men compared with those without DM (RR: 1.23; 95% CI: 1.06-1.42; P = .005), whereas no significant relationship was observed between DM and bladder cancer in women (RR: 1.24; 95% CI: 0.95-1.61; P = .119). There was no significant gender difference for this relationship (ratio of RR: 0.99; 95% CI: 0.73-1.34; P = .958). In addition, cancer incidence (RR: 1.21; 95% CI: 1.09-1.35; P < .001) and cancer mortality (RR: 1.25; 1.17-1.35; P < .001) both increased in DM patients. Finally, smoking status and follow-up duration might also affect this relationship in men and women.

CONCLUSIONS

The findings of this study indicated that DM was associated with elevated bladder cancer or cancer mortality risk, especially in men. This relationship in women requires further exploration.

Diabetes mellitus and risk of ovarian cancer. A systematic review and meta-analysis of 15 cohort studies

AIM

Diabetes mellitus (DM) is hypothesized to be associated with an increased risk of ovarian cancer (OC), but current evidences are inconsistent. We aimed to further study this association.

METHODS

PubMed, EMBASE, Web of Science, and Scopus were searched for eligible articles. After descriptive summary of the data, a random-effects model was applied in quantitative synthesis. Subgroup analysis was performed by study locales and settings, and sensitivity analysis was conducted based on restrictive selection criteria. Funnel plots and the Egger's test were used to assess publication bias. Statistical heterogeneity in meta-analysis was assessed by the P value derived from the Cochrane Q statistic and I-squared value.

RESULTS

Fourteen articles involving data of 15 cohort studies were included for our research. Overall, 17 risk ratios (RRs) were synthesized and yielded a pooled RR of 1.32 (95%CI: 1.14-1.52, P_Cochrane<0.001, I²=79.8%). Thirteen RRs were synthesized for type 2DM, and the pooled RR was 1.24 (95%CI: 1.06-1.44, P_Cochrane<0.001, I²=81.8%). Four RRs were synthesized for type 1DM, and the result was significant (RR: 1.83, 95%CI: 1.21-2.78, P_Cochrane=0.080, I²=55.7%). Results of sensitivity analysis suggested the robustness of a positive association between DM and OC risk, and subgroup analysis demonstrated that the association between DM and OC was much more substantial among Asia population. No publication bias was identified in meta-analysis.

CONCLUSION

Our study suggests there is a moderate relative increase in the risk of OC among DM patients. Future studies should investigate the effect of duration of DM and anti-diabetes intervention to OC risk.

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.

Risk of skin cancer in patients with diabetes mellitus: A nationwide retrospective cohort study in Taiwan

Increasing evidence suggests that certain types of cancers are more common in people with diabetes mellitus (DM). This study aimed to investigate the risk of skin cancer in patients with DM in Taiwan. In this retrospective cohort study using data from the Taiwan Longitudinal Health Insurance Research Database, the risk of developing overall skin cancer, including nonmelanoma skin cancer (NMSC) and melanoma, was compared by Poisson regression analysis and Cox regression analysis between the DM and non-DM cohorts. The DM cohort with newly diagnosed DM (n = 41,898) and a non-DM cohort were one-to-one matched by age, sex, index date, and comorbidities (coronary artery disease, hyperlipidemia, hypertension, chronic kidney disease, chronic obstructive pulmonary disease, and obesity). Compared with non-DM cohort statistically, for the people with DM aged ≥60 years, the incidence rates of overall skin cancer and NMSC were significantly higher (overall: DM/non-DM: number [n] = 99/76, incidence rate ratio [IRR] = 1.44, P = 0.02; NMSC: DM/non-DM: n = 94/66, IRR = 1.57, P = 0.005). By Cox regression analysis, the risk of developing overall skin cancer or NMSC was significantly higher after adjusting for sex, comorbidities, and overall diseases with immunosuppression status (overall: adjusted hazard ratio [AHR] = 1.46, P = 0.01; NMSC: AHR = 1.6, P = 0.003). Other significant risk factors were older males for skin cancer (overall: AHR = 1.68, P = 0.001; NMSC: AHR = 1.59, P = 0.004; melanoma: AHR = 3.25, P = 0.04), chronic obstructive pulmonary disease for NMSC (AHR = 1.44, P = 0.04), and coronary artery disease for melanoma (AHR = 4.22, P = 0.01). The risk of developing melanoma was lower in the DM cohort than in the non-DM cohort, but without significance (AHR = 0.56, P = 0.28; DM/non-DM: n = 5/10). The incidence rate and risk of developing overall skin cancer, including NMSC, was significantly higher in older adults with DM. Other significant risk factors for older adults with DM were males for NMSC and melanoma, chronic obstructive pulmonary disease for NMSC, and coronary artery disease for melanoma.

Risk of Malignant Neoplasms of Kidney and Bladder in a Cohort Study of the Diabetic Population in Taiwan With Age, Sex, and Geographic Area Stratifications

Diabetes has been reported to increase the risk of malignant neoplasms of kidney and bladder, but the studies' results are still inconclusive. Age, sex, and geographical area-specific incidence and relative risks of above neoplasms are also scarce in the literature. We prospectively investigated the age, sex, geographical area-specific incidence and relative risks of kidney and bladder neoplasms in diabetic population of Taiwan. Diabetic patients (n = 615,532) and age- and sex-matched controls (n = 614,871) were linked to inpatient claims (2000-2008) to identify the admissions for malignant neoplasm of kidney (International Classification of Diagnosis, 9th version, Clinical Modification: 189) and bladder (International Classification of Diagnosis, 9th version, Clinical Modification: 188). The person-year approach with Poisson assumption was used to evaluate the incidence density. We also estimated the age, sex, and geographical area-specific relative risks of above malignancy in relation to diabetes with Cox proportional hazard regression model. The overall incidence density of malignant neoplasm of kidney for diabetic men and women were 3.87 and 4.28 per 10,000 patient-years, respectively; the corresponding figures for malignant neoplasm of bladder were 5.73 and 3.25 per 10,000 patient-years. Compared with the controls, diabetic men were at significantly increased hazards of kidney (covariate adjusted hazard ratio [aHR]: 1.31, 95% confidence interval [CI] 1.18-1.46) and bladder aHR: 1.13, 95% CI 1.04-1.23). Diabetic women, on the contrary, only experienced significantly elevated hazard of kidney neoplasm (aHR: 1.14, 95% CI 1.04-1.26). Diabetic men aged >65 years showed the most significantly increased hazard of developing neoplasm of kidney (aHR: 1.40) and bladder (aHR: 1.13). The most significantly increased hazard of kidney neoplasm was noted for women diabetic patients aged >65 years. There was also a significant interactive effect of geographic area with diabetes on the incidence of kidney and bladder neoplasms in both sexes. Diabetic men >45 years and diabetic women >65 years were found to have significantly increased hazard of malignant neoplasm of kidney, but only diabetic men >65 years were at significantly increased hazard of bladder neoplasm. The significant geographic variations in incidence and relative hazard of kidney and bladder neoplasms warrant further investigations of the underlying reasons.

Long-Term Diabetes Mellitus Is Associated with an Increased Risk of Pancreatic Cancer: A Meta-Analysis

Purpose

Previous studies have shown a bidirectional relationship between diabetes and pancreatic cancer (PC). In particular, new-onset diabetes might be induced by PC, and people with long-term diabetes might be at increased risk for the development of PC. The purpose of our study was to examine whether long-term diabetes represented an independent risk factor for PC development.

Methodology

A literature search was performed by searching electronic databases for studies published before July 1, 2014, and relative risks (RRs) and corresponding 95% confidence intervals (CIs) were calculated. Data pertaining to diabetes were recorded at both individual and study levels, with RRs calculated separately to analyze the relationship between the duration of diabetes and the development of PC.

Results

Forty-four studies were included in this meta-analysis, including 18 studies with a case-control design, 5 with a nested case-control design and 21 with a cohort design. The overall summary estimate for the relationship between the population with a duration of diabetes ≥2 years and PC was 1.64 (1.52-1.78). The pooled RR (95% CI) of PC for the population with a duration of diabetes ≥5 years was 1.58 (1.42-1.75). For the population with a duration of diabetes ≥10 years, the RR (95% CI) of PC was 1.50 (1.28-1.75).

Conclusions

Our study suggests that long-term diabetes mellitus is associated with an increased risk of PC. However, the level of risk is negatively correlated with increasing diabetes mellitus duration.

Inhibition of hyperglycemia-induced angiogenesis and breast cancer tumor growth by systemic injection of microRNA-467 antagonist

Abnormal angiogenesis in multiple tissues is a key characteristic of the vascular complications of diabetes. However, angiogenesis may be increased in one tissue but decreased in another in the same patient at the same time point in the disease. The mechanisms of aberrant angiogenesis in diabetes are not understood. There are no selective therapeutic approaches to target increased neovascularization without affecting physiologic angiogenesis and angiogenesis in ischemic tissues. We recently reported a novel miRNA-dependent pathway that up-regulates angiogenesis in response to hyperglycemia in a cell- and tissue-specific manner. The goal of the work described herein was to test whether systemic administration of an antagonist of miR-467 would prevent hyperglycemia-induced local angiogenesis in a tissue-specific manner. We examined the effect of the antagonist on hyperglycemia-induced tumor growth and angiogenesis and on skin wound healing in mouse models of diabetes. Our data demonstrated that the systemic injection of the antagonist prevented hyperglycemia-induced angiogenesis and growth of mouse and human breast cancer tumors, where the miR-467 pathway was active in hyperglycemia. In tissues where the miR-467-dependent mechanism was not activated by hyperglycemia, there was no effect of the antagonist: the systemic injection did not affect skin wound healing or the growth of prostate tumors. The data show that systemic administration of the miR-467 antagonist could be a breakthrough approach in the treatment and prevention of diabetes-associated breast cancer in a tissue-specific manner without affecting physiologic angiogenesis and angiogenesis in ischemic tissues.

Risk of dementia in patients hospitalised with type 1 and type 2 diabetes in England, 1998-2011: a retrospective national record linkage cohort study

AIMS/HYPOTHESIS

Type 2 diabetes increases the risk of subsequent dementia. Our objective was to determine whether a similar risk of subsequent dementia is associated with type 1 diabetes in a large defined population.

METHODS

This retrospective cohort study examined national administrative record-linked statistical data on hospital care and mortality in England, 1998-2011. Cohorts of people admitted to hospital when aged 30 or over were constructed: 343,062 people with type 1 diabetes; 1,855,141 people with type 2 diabetes; and a reference cohort. Results were expressed as rate ratios (RR) comparing each diabetes cohort with the control cohort.

RESULTS

The overall RR for dementia in people admitted to hospital with type 1 diabetes was 1.65 (95% CI 1.61, 1.68), and for people admitted to hospital with type 2 diabetes was 1.37 (1.35, 1.38). Young age at admission for diabetes appeared to confer a greater rate of subsequent dementia; the RR for dementia in people admitted to hospital with type 1 diabetes aged 30-39 years was 7.10 (4.65, 10.6), which reduced to 4.40 (3.55, 5.40) in those aged 40-49 at admission, and further reduced with increasing age to 1.16 (1.11, 1.20) in those aged 80 or over at admission. A similar pattern was seen with type 2 diabetes.

CONCLUSIONS/INTERPRETATION

Type 1 diabetes, as well as type 2 diabetes, may be associated with an elevated risk of subsequent dementia. The risk of dementia varies with age at admission to hospital with diabetes, and appears to be much greater in the young.

Type 2 diabetes mellitus and risk of oral cancer and precancerous lesions: a meta-analysis of observational studies

OBJECTIVE

Associations between type 2 diabetes mellitus (type 2 DM) and risk of oral cancer and precancerous lesions have been reported with controversial findings. We performed a meta-analysis to explore these associations.

METHODS

We identified studies by a literature search of MEDLINE and EMBASE through May 31, 2014, and by searching the reference lists of pertinent articles. Summary relative risk (SRR) with 95% confidence interval (CI) was calculated with a random-effects model. Between- study heterogeneity was assessed using the Cochran's Q and I(2) statistics.

RESULTS

A total of 13 studies (4 case-control and 9 cohort studies) on the association between type 2 DM and oral cancer were included. Overall analysis found that compared with non-diabetic individuals, individuals with type 2 DM had a significantly elevated incidence of oral cancer (SRR=1.15, 95% CI: 1.02-1.29; Pheterogeneity=0.277, I(2)=15.4%; 10 studies). Subgroup analyses found that duration of follow-up (⩾11years) significantly altered this positive association. Type 2 DM was associated with increased oral cancer mortality (SRR=1.41, 95% CI: 1.16-1.72; 4 studies). Meta-analysis of the four case-control studies showed a positive association between type 2 DM and risk of oral precancerous lesions (SRR=1.85, 95%CI: 1.23-2.80; Pheterogeneity=0.038, I(2)=57.5%). No significant public bias was found across these studies.

CONCLUSIONS

These findings of this meta-analysis indicate that compared with non-diabetic individuals, individuals with type 2 DM have an elevated risk of oral cancer and precancerous lesions development.

Diabetes mellitus and the risk of prostate cancer: an update and cumulative meta-analysis

INTRODUCTION

To provide further insight into the association between type 2 diabetes mellitus (T2DM) and the pathophysiology of prostate cancer, we conducted an updated, detailed meta-analysis of 56 published case-control and cohort studies.

METHODS

MEDLINE and EMBASE were used to identify the literature published in April 2012 related to both diabetes mellitus and prostate cancer. A sensitivity analysis was performed, and potential confounding effects were investigated using a stratified meta-analysis. A cumulative meta-analysis was also carried out to evaluate the cumulative effect estimate over time.

RESULTS

A total of 24 case-control and 32 cohort studies with information on a total of ~8,000,000 subjects and ~140,000 individuals with prostatic cancer showed published estimates of the association between diabetes and prostate cancer malignancy. The pooled effect estimate revealed a relative risk (RR) of 0.88 (95% CI, 0.82-0.93). Interestingly, there was an increased trend for Asians (RR = 1.72, n = 7) but not Americans (RR = 0.82, n = 28) and Europeans (RR = 0.86, n = 21) regarding the association between diabetes mellitus and prostate cancer. The sensitivity analysis, excluding any one study, did not significantly change the pooled RR. The range for the pooled RR when one study was omitted was 0.84-0.89.

DISCUSSION

The findings of our meta-analysis provide strong evidence of an inverse association between diabetes and prostate cancer.

CONCLUSIONS

Further research should focus on limitations in the current literature and re-assess the relationship between diabetes and prostate cancer by analyzing the two different diabetes mellitus types separately.

CARING (CAncer Risk and INsulin analoGues): the association of diabetes mellitus and cancer risk with focus on possible determinants - a systematic review and a meta-analysis

Background:

Patients suffering from diabetes mellitus (DM) may experience an increased risk of cancer; however, it is not certain whether this effect is due to diabetes per se.

Objective:

To examine the association between DM and cancers by a systematic review and meta-analysis according to the PRISMA guidelines.

Data Sources:

The systematic literature search includes Medline at PubMed, Embase, Cinahl, Bibliotek.dk, Cochrane library, Web of Science and SveMed+ with the search terms: “Diabetes mellitus”, “Neoplasms”, and “Risk of cancer”.

Study Eligibility Criteria:

The included studies compared the risk of cancer in diabetic patients versus non-diabetic patients. All types of observational study designs were included.

Results:

Diabetes patients were at a substantially increased risk of liver (RR=2.1), and pancreas (RR=2.2) cancer. Modestly elevated significant risks were also found for ovary (RR=1.2), breast (RR=1.1), cervix (RR=1.3), endometrial (RR=1.4), several digestive tract (RR=1.1-1.5), kidney (RR=1.4), and bladder cancer (RR=1.1). The findings were similar for men and women, and unrelated to study design. Meta-regression analyses showed limited effect modification of body mass index, and possible effect modification of age, gender, with some influence of study characteristics (population source, cancer- and diabetes ascertainment).

Limitations:

Publication bias seemed to be present. Only published data were used in the analyses.

Conclusions:

The systematic review and meta-analysis confirm the previous results of increased cancer risk in diabetes and extend this to additional cancer sites. Physicians in contact with patients with diabetes should be aware that diabetes patients are at an increased risk of cancer.

Plasma insulin, C-peptide and blood glucose and the risk of gastric cancer: the Japan Public Health Center-based prospective study

To date, the association between diabetes mellitus (DM) and gastric cancer has been controversial, including the underlying mechanism. We investigated the association between plasma diabetic biomarkers (insulin, C-peptide, and blood glucose) and gastric cancer risk. In addition, homeostasis model assessment of insulin resistance (HOMA-IR) and homeostasis model assessment of β-cell function (HOMA-β) were calculated. A total of 36,745 subjects aged 40-69 years in the Japan Public Health Center-based prospective study (JPHC) who returned the baseline questionnaire and provided blood samples were followed from 1990 to 2004. In the present analysis, 477 cases and 477 matched controls were used. The odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) for developing gastric cancer were calculated using conditional logistic regression models. Plasma insulin was positively associated with increased risk of gastric cancer; compared to tertile 1, ORs were 1.69 (95% CI = 1.11-2.59) and 2.01 (1.19-3.38) for tertiles 2 and 3, respectively (p for trend = 0.009). In men, C-peptide was also positively associated with a significant risk; corresponding ORs were 1.42 (0.85-2.38) and 1.91 (1.03-3.54), respectively (p for trend = 0.04). These findings were confirmed for blood samples from the fasting group (≥8 hr after a meal). Higher HOMA-IR was also associated with increased risk, whereas no association was observed for blood glucose. Our findings suggest that Japanese population with higher insulin and C-peptide levels derived from insulin resistance have an elevated risk of gastric cancer.

Is diabetes mellitus associated with increased incidence and disease-specific mortality in endometrial cancer? A systematic review and meta-analysis of cohort studies

OBJECTIVE

To assess the association between diabetes mellitus (DM) and the incidence and disease-specific mortality of endometrial cancer (EC).

METHODS

MEDLINE, EMBASE and conference abstracts of the 2011-2013 Annual Meetings of Society of Gynecological Oncology were searched for reports of original cohort studies that enrolled diabetic and non-diabetic women who were free of EC at baseline to compare the incidence and disease-specific mortality of EC by DM status. The included reports were examined for demographic characteristics of study populations, study design, effect measures and risk of bias. Statistical heterogeneity was evaluated with Chi-square test of the Cochrane Q statistics at the 0.05 significance level and I(2) statistic. Publication bias was assessed by visual examination of a funnel plot and the Egger's test for small-study effects.

RESULTS

Twenty-nine cohort studies (17 prospective, 12 retrospective) were eligible for this review, 23 of which reported EC incidence, five reported disease-specific mortality and one reported both. For incidence of EC among women with versus without DM, the summary relative risk (RR) was 1.89 (95%CI, 1.46-2.45; p<0.001) and the summary incidence rate ratio was 1.61 (95%CI, 1.51-1.71; p<0.001). The pooled RR of disease-specific mortality was 1.32 (95%CI, 1.10-1.60; p=0.003), while results in the studies reporting standardized mortality ratios were inconsistent. There remains considerable amount of clinical and methodological heterogeneity among the included studies; moreover, the hazard ratios for incident EC showed significant statistical heterogeneity and therefore were not quantitatively synthesized.

CONCLUSIONS

There is consistent evidence for an independent association between DM and an increased risk of incident EC, while the association between DM and EC-specific mortality remains uncertain. Further studies with better considerations for selection bias, information bias and confounding will further facilitate causal inference involving DM and EC.

Pre-existing type 2 diabetes and risk of lung cancer: a report from two prospective cohort studies of 133 024 Chinese adults in urban Shanghai

OBJECTIVES

Observational studies of type 2 diabetes (T2D) and lung cancer risk are limited and controversial. We thus examined the association between T2D and risk of incident lung cancer using a cohort design.

SETTING

Data from two ongoing population-based cohorts (the Shanghai Men's Health Study, SMHS, 2002-2006 and the Shanghai Women's Health Study, SWHS, 1996-2000) were used. Cox proportional-hazards regression models with T2D as a time-varying exposure were modelled to estimate HRs and 95% CIs.

PARTICIPANTS

The study population included 61 491 male participants aged 40-74 years from SMHS and 74 941 female participants aged 40-70 years from SWHS.

OUTCOME MEASURE

Lung cancer cases were identified through annual record linkage to the Shanghai Cancer Registry and Shanghai Municipal Registry of Vital Statistics, and were further verified through home visits and a review of medical charts by clinical and/or pathological experts. Outcome data until 31 December 2010 for men and women were used for the present analysis.

RESULTS

After a median follow-up of 6.3 years for SMHS and 12.2 years for SWHS, incident lung cancer cases were detected in 492 men and 525 women. A null association between T2D and lung cancer risk was observed in men (HR=0.87, 95% CI 0.62 to 1.21) and women (HR=0.92, 95% CI 0.69 to 1.24) after adjustments for potential confounders. Similar results were observed among never smokers.

CONCLUSIONS

There is little evidence that pre-existing T2D may influence the incidence of lung cancer.

Association of diabetes mellitus and pancreatic adenocarcinoma: a meta-analysis of 88 studies

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is often diagnosed at an advanced, incurable stage. Previous epidemiological data suggests that diabetes mellitus (DM) is a risk factor for PDAC, which may be important in early detection. However, the strength of this association needs to be determined, taking into account a number of recently published studies.

METHODS

A systematic review of the association between DM and PDAC was undertaken by searching electronic databases and journal references from 1973 to 2013. Summary estimates were obtained separately for case-control and cohort studies by means of a 'random effects' approach. Data pertaining to the DM was recorded and plotted at both an individual and study level, with the relative risks (RR) pooled separately to determine the relationship of DM duration and PDAC.

RESULTS

A total of 88 independent studies, including 50 cohort and 39 case-control studies were examined. The overall summary-combined RR was 1.97 (95 % CI 1.78-2.18) with marked heterogeneity that could not be clearly attributed to any subgroup analyses. The risk of PDAC was greatest early after the diagnosis of DM but remained elevated long after the diagnosis. The individual-level RR ranged from 6.69 at less than 1 year to 1.36 at 10 years.

CONCLUSION

The results demonstrate a strong association between PDAC and recently diagnosed DM, which may be attributed to a paraneoplastic effect. However, the presence of diabetes also remains a modest risk factor for the development of PDAC long-term. Selective screening of patients with new-onset DM for PDAC needs to be considered.

Diabetes mellitus increases the risk of gastric cancer: A meta-analysis

AIM: To systematically assess the association between diabetes mellitus and the risk of gastric cancer.

METHODS: We searched Medline (PubMed), EMBASE, the Cochrane Library and CBN databases from January 1990 to July 2013. We also searched the references of qualifying articles. Cohort studies comparing the risk of gastric cancer between diabetic patients and control subjects were included. Fifteen studies met our criteria, and the quality of these studies was assessed using the Newcastle-Ottawa Quality Assessment Scale. Meta-analysis was performed using the random-effects model (DerSimonian-Laird method).

RESULTS: The meta-analysis showed an increased gastric cancer risk in diabetic patients [relative risk (RR) = 1.15, 95%CI: 1.11-1.19].

CONCLUSION: Diabetes mellitus may increase the risk of gastric cancer.

Risk of bladder cancer in patients with diabetes mellitus: an updated meta-analysis of 36 observational studies

BACKGROUND

Increasing evidence suggests that a history of diabetes mellitus (DM) may be associated with an increased risk of bladder cancer. We performed a systematic review with meta-analysis to explore this relationship.

METHODS

We identified studies by a literature search of Medline (from 1 January 1966) and EMBASE (from 1 January 1974), through 29 February 2012, and by searching the reference lists of pertinent articles. Summary relative risks (RRs) with corresponding 95% confidence intervals (CIs) were calculated with a random-effects model.

RESULTS

A total of 36 studies (9 case-control studies, 19 cohort studies and 8 cohort studies of patients with diabetes) fulfilled the inclusion criteria. Analysis of all studies showed that DM was associated with an increased risk of bladder cancer (the summary RR = 1.35, 95% CI 1.17-1.56, p < 0.001, I2 = 94.7%). In analysis stratified by study design, diabetes was positively associated with risk of bladder cancer in case-control studies (RR = 1.45, 95% CI 1.13-1.86, p = 0.005, I2 = 63.8%) and cohort studies (RR = 1.35, 95% CI 1.12-1.62, p < 0.001, I2 = 94.3%), but not in cohort studies of diabetic patients (RR = 1.25, 95% CI 0.86-1.81, p < 0.001, I2 = 97.4%). The RRs of bladder cancer were 1.38 (1.08-1.78) for men and 1.38 (0.90-2.10) for women with diabetes, respectively. Noteworthy, the relative risk of bladder cancer was negatively correlated with the duration of DM, with the higher risk of bladder cancer found among patients diagnosed within less than 5 years.

CONCLUSIONS

These findings support the hypothesis that men with diabetes have a modestly increased risk of bladder cancer, while women with diabetes were not the case.

Diabetes mellitus as an independent risk factor for lung cancer: a meta-analysis of observational studies

BACKGROUND

Epidemiologic studies have demonstrated inconsistent associations between diabetes mellitus and the risk of lung cancer. To determine whether diabetes mellitus is associated with an increased risk of lung cancer, we performed a meta-analysis of observational studies.

METHODS

PubMed, EMBASE and the Cochrane Library were searched for observational studies conducted prior to September 2012. We included prospective cohort studies that reported relative risks and case-control studies that showed odds ratios in the analysis. The pooled relative risk (RR) with 95% confidence intervals (CIs) was calculated with a random effects model. Sensitivity analysis was performed with studies which controlled for smoking status. Associations were assessed in several subgroups representing different participant and study characteristics.

RESULTS

A total of 34 studies from 24 manuscripts (10 case-control studies and 24 cohort studies) were included in the analyses. Diabetes was significantly associated with the increased risk of lung cancer compared with non-diabetic controls when limiting the analysis to studies adjusting for smoking status (RR, 1.11; 95% CI, 1.02-1.20; I(2)=46.1%). By contrast, this association disappeared when the analysis was restricted to studies not adjusting for smoking status (RR, 0.99; 95% CI, 0.88-1.11; I(2)=96.7%). When stratifying by sex, an increased risk of lung cancer was prominent in diabetic women (RR, 1.14; 95% CI, 1.09-1.20; I(2)=0%), while there was no association in diabetic men (RR, 1.07; 95% CI, 0.89-1.28; I(2)=96.6%). Among diabetic women, significantly increased risks of lung cancer were found in the following subgroups: cohort studies (RR, 1.14; 95% CI, 1.08-1.20; I(2)=0%), studies controlling for major confounding variables such as age, smoking and alcohol (RR, 1.19; 95% CI, 1.00-1.43; I(2)=23.1%), studies with long-term follow-up (RR, 1.14; 95% CI, 1.08-1.20; I(2)=0%), and high-quality studies assessed by the Newcastle-Ottawa Scale (RR, 1.14; 95% CI, 1.08-1.20; I(2)=0%).

INTERPRETATION

Preexisting diabetes mellitus may increase the risk of lung cancer, especially among female diabetic patients. Further large-scale prospective studies are needed to test specifically the effect of diabetes mellitus on lung cancer risk.

The links between insulin resistance, diabetes, and cancer

The growing epidemic of obesity has resulted in a large increase in multiple related diseases. Recent evidence has strengthened the proposed synergistic relationship between obesity-related insulin resistance (IR) and/or diabetes mellitus (DM) and cancer. Within the past year, many studies have examined this relationship. Although the precise mechanisms and pathways are uncertain, it is becoming clear that hyperinsulinemia and possibly sustained hyperglycemia are important regulators of not only the development of cancer but also of treatment outcome. Further, clinical decision-making regarding the treatment of choice for DM will likely be impacted as we learn more about the non-metabolic effects of the available hyperglycemic agents. In our review, we endeavored to synthesize the recent literature and provide a concise view of the journey from macro-level clinical associations to specific mechanistic relationships being elucidated in cell lines and animal models.

Diabetes mellitus and risk of bladder cancer: a meta-analysis of cohort studies

OBJECTIVE

Diabetes is associated with increased risk of cancer at several sites, but its association with risk of bladder cancer is still controversial. We examined this association by conducting a systematic review and meta-analysis of cohort studies.

METHODS

Studies were identified by searching PubMed, EMBASE, Scopus, Web of Science, Cochrane register, and Chinese National Knowledge Infrastructure (CNKI) databases through April 29, 2012. Summary relative risks (SRRs) with their corresponding 95% confidence intervals (CIs) were calculated using a random-effects model.

RESULTS

A total of fifteen cohort studies were included in this meta-analysis. Analysis of all studies showed that diabetes was associated with a borderline statistically significant increased risk of bladder cancer (RR 1.11, 95% CI 1.00-1.23; p<0.001 for heterogeneity; I(2) = 84%). When restricting the analysis to studies that had adjusted for cigarette smoking (n = 6) or more than three confounders (n = 7), the RRs were 1.32 (95% CI 1.18-1.49) and 1.20 (95% CI 1.02-1.42), respectively. There was no significant publication bias (p = 0.62 for Egger's regression asymmetry test).

CONCLUSIONS

Our findings support that diabetes was associated with an increased risk of bladder cancer. More future studies are warranted to get a better understanding of the association and to provide convincing evidence for clinical practice in bladder cancer prevention.

Diabetes Mellitus and Ovarian Cancer Risk: A Systematic Review and Meta-Analysis of Observational Studies

Objective

The objective of this study was to evaluate the epidemiologic association between diabetes and risk of ovarian cancer.

Methods

We searched PubMed, EMBASE, and The Cochrane Library for observational studies on the association between diabetes and ovarian cancer. Cohort studies that reported relative risks (RRs) and case-control studies that showed odds ratios were included in the analysis. Summary RRs with 95% confidence intervals (CIs) were calculated with a random-effects model.

Results

A total of 19 studies from 18 articles (7 case-control studies and 11 cohort studies) met the inclusion criteria. Combining data from all studies, diabetes was associated with an increased risk of ovarian cancer, compared with no diabetes (summary RR of ovarian cancer incidence, 1.17; 95% CI, 1.02–1.33). In cohort and nested case-control studies, patients with diabetes had statistically significant increased risk of ovarian cancer (RR, 1.16; 95% CI, 1.01–1.33), without significant heterogeneity (I2 = 27; P = 0.172). Among studies that control for age, body mass index, smoking, and alcohol, a prominent association between diabetes and ovarian cancer was found (RR, 1.55; 95% CI, 1.11–2.19).

Conclusions

This study suggests that women with diabetes have a moderately increased risk of ovarian cancer.

Diabetes mellitus and risk of bladder cancer: a meta-analysis of cohort studies

Background

Increasing evidence suggests that diabetes mellitus (DM) may be associated with an increased risk of bladder cancer. To provide a quantitative assessment of this association, we evaluated the relation between DM and incidence and mortality of bladder cancer in an updated meta-analysis of cohort studies.

Methods We identified cohort studies by searching the EMBASE and MEDLINE databases, through 31 March 2012. Summary relative risks (RRs) with 95% confidence intervals (CIs) were calculated with random-effects models.

Results

A total of 29 cohort studies (27 articles) were included in this meta-analysis. DM was associated with an increased incidence of bladder cancer (RR 1.29, 95% CI: 1.08–1.54), with significant evidence of heterogeneity among these studies (p<0.001, I² = 94.9%). In stratified analysis, the RRs of bladder cancer were 1.36 (1.05–1.77) for diabetic men and 1.28 (0.75–2.19) for diabetic women, respectively. DM was also positively associated with bladder cancer mortality (RR 1.33, 95% CI: 1.14–1.55), with evident heterogeneity between studies (p = 0.002, I² = 63.3%). The positive association was observed for both men (RR 1.54, 95% CI: 1.30–1.82) and women (RR 1.50, 95% CI: 1.05–2.14).

Conclusion

These findings suggest that compared to non-diabetic individuals, diabetic individuals have an increased incidence and mortality of bladder cancer.

Pre-existing diabetes mellitus increases the risk of gastric cancer: A meta-analysis

AIM: To systematically assess the association between diabetes and incidence of gastric cancer.

METHODS: We searched MedLine (PubMed), EMBASE, and the Cochrane Library without any limitations with respect to publication date or language, we also searched the references of qualifying articles. Case-control studies and cohort studies comparing the risk of gastric cancer between diabetic patients and control subjects were included. We excluded studies reporting only standardized incidence ratios without control groups and those that investigated only mortality but not incidence. Seventeen studies met our criteria, and the qualities of these studies were assessed using the Newcastle-Ottawa Quality Assessment Scale. We performed a meta-analysis of pre-existing diabetes and gastric cancer incidence using the DerSimonian-Laird method for random-effects. For subgroup analyses, we separated the studies by study type, region, sex and method to determine confounding factors and reliability. We also conducted subgroup analyses to examine the effects of smoking, Helicobacter pylori (H. pylori) infection, and cancer site. Publication bias was evaluated using Begg’s test.

RESULTS: A random-effects model meta-analysis showed an increased gastric cancer risk in diabetic patients [relative risk (RR) = 1.19; 95%CI: 1.08-1.31]. Subgroup analyses indicated that this result persisted in cohort studies (RR = 1.20; 95%CI: 1.08-1.34), in studies on populations of both Western (RR = 1.18; 95%CI: 1.03-1.36) and Eastern countries (RR = 1.19; 95%CI: 1.02-1.38), in a female subgroup (RR=1.24; 95%CI: 1.01-1.52), and in highly qualified studies (RR = 1.17; 95%CI: 1.05-1.31). Moreover, these results persisted when the analysis was confined to studies adjusted for well-known gastric cancer risk factors such as smoking (RR = 1.17; 95%CI: 1.01-1.34) and H. pylori infection (RR = 2.35; 95%CI: 1.24-4.46).

CONCLUSION: Pre-existing diabetes mellitus may increase the risk of gastric cancer by approximately 19%. This effect seems to be unrelated to geographical region.

Novel tissue-specific mechanism of regulation of angiogenesis and cancer growth in response to hyperglycemia

Background

Hyperglycemia is an independent risk factor for the development of vascular diabetic complications, which are characterized by endothelial dysfunction and tissue‐specific aberrant angiogenesis. Tumor growth is also dependent on angiogenesis. Diabetes affects several cancers in a tissue‐specific way. For example, it positively correlates with the incidence of breast cancer but negatively correlates with the incidence of prostate cancer. The tissue‐specific molecular mechanisms activated by hyperglycemia that control angiogenesis are unknown. Here we describe a novel tissue‐ and cell‐specific molecular pathway that is activated by high glucose and regulates angiogenesis.

Methods and Results

We have identified microRNA 467 (miR‐467) as a translational suppressor of thrombospondin‐1 (TSP‐1), a potent antiangiogenic protein that is implicated in the pathogenesis of several diabetic complications. miR‐467 was upregulated by hyperglycemia in a tissue‐specific manner. It was induced by high glucose in microvascular endothelial cells and in breast cancer cells, where it suppressed the production of TSP‐1 by sequestering mRNA in the nonpolysomal fraction. Mutation of the miR‐467 binding site in TSP‐1 3′ UTR or miR‐467 inhibitor relieved the translational silencing and restored TSP‐1 production. In in vivo angiogenesis models, miR‐467 promoted the growth of blood vessels, and TSP‐1 was the main mediator of this effect. Breast cancer tumors showed increased growth in hyperglycemic mice and expressed higher levels of miR‐467. The antagonist of miR‐467 prevented the hyperglycemia‐induced tumor growth.

Conclusions

Our results demonstrate that miR‐467 is implicated in the control of angiogenesis in response to high glucose, which makes it an attractive tissue‐specific potential target for therapeutic regulation of aberrant angiogenesis and cancer growth in diabetes.

Diabetes, obesity and cancer: risk and anti-risk factors

Observable diabetes and obesity epidemics may result in alteration of cancer morbidity and mortality. This increasingly recognized problem is reviewed here from the perspective of interplay between factors that differently modify association of diabetes mellitus with malignant neoplasms. Heterogeneity and familial aspects of diabetes and obesity, genomic traits, anti-diabetic medications and weight-reducing treatment are important examples of such factors. Addressing them might promote development of efficient preventive measures.

Type 2 diabetes and risk of prostate cancer: a meta-analysis of observational studies

BACKGROUND

Emerging evidence suggests that diabetes may increase the risk of cancers. However, available evidence on prostate cancer is conflicting. We therefore examined the association between Type 2 diabetes and risk of prostate cancer by conducting a detailed meta-analysis of all studies published regarding this subject.

METHODS

PubMed database and bibliographies of retrieved articles were searched for epidemiological studies (published between 1970 and 2011), investigating the relationship between Type 2 diabetes and prostate cancer. Pooled risk ratio (RR) was calculated using random-effects model. Subgroup, sensitivity analysis and cumulative meta-analysis were also done.

RESULTS

Forty-five studies (29 cohort and 16 case-control studies) involving 8.1 million participants and 132 331 prostate cancer cases detected a significant inverse association between Type 2 diabetes and risk of prostate cancer (RR 0.86, 95% confidence interval (CI) 0.80-0.92). For cohort studies alone, the RR was 0.87 (95% CI 0.80-0.94), and for case-control studies alone, the RR was 0.85 (95% CI 0.74-0.96). Sensitivity analysis done by excluding one outlier further strengthened our negative association (RR 0.83, 95% CI 0.78-0.87). No evidence of publication bias was observed.

CONCLUSIONS

This meta-analysis provides strongest evidence supporting that Type 2 diabetes is significantly inversely associated with risk of developing prostate cancer.

Diabetes and cancer II: role of diabetes medications and influence of shared risk factors

An association between type 2 diabetes mellitus (DM) and cancer has long been postulated, but the biological mechanism responsible for this association has not been defined. In part one of this review, we discussed the epidemiological evidence for increased risk of cancer, decreased cancer survival, and decreased rates of cancer screening in diabetic patients. Here we review the risk factors shared by cancer and DM and how DM medications play a role in altering cancer risk. Hyperinsulinemia stands out as a major factor contributing to the association between DM and cancer, and modulation of circulating insulin levels by DM medications appears to play an important role in altering cancer risk. Drugs that increase circulating insulin, including exogenous insulin, insulin analogs, and insulin secretagogues, are generally associated with an increased cancer risk. In contrast, drugs that regulate insulin signaling without increasing levels, especially metformin, appear to be associated with a decreased cancer risk. In addition to hyperinsulinemia, the effect of DM medications on other shared risk factors including hyperglycemia, obesity, and oxidative stress as well as demographic factors that may influence the use of certain DM drugs in different populations are described. Further elucidation of the mechanisms behind the association between DM, cancer, and the role of DM medications in modulating cancer risk may aid in the development of better prevention and treatment options for both DM and cancer. Additionally, incorporation of DM medication use into cancer prediction models may lead to the development of improved risk assessment tools for diabetic patients.