Prevalent diabetes and risk of total, colorectal, prostate and breast cancers in an ageing population: meta-analysis of individual participant data from cohorts of the CHANCES consortium

Association Between Diabetes and Risk of Prostate Cancer: A Systematic Review and Meta-Analysis of Observational Studies

PURPOSE

Metabolic diseases such as diabetes mellitus may play a role in the development and progression of prostate cancer (PC); however, this association remains to be explored in the context of specific PC stages. The objective of this study was to systematically review the evidence for an association between diabetes and overall, early, or advanced PC risk.

MATERIALS AND METHODS

A systematic review with meta-analysis was performed (MEDLINE, EMBASE, and CINAHL) from inception until September 2023. Cohort and case-control studies that assessed PC risk in adult males (≥18 years) associated with type 2 diabetes mellitus or diabetes (if there was no distinction between diabetes type) were included. The Newcastle-Ottawa Scale (NOS) was used to assess study bias; those with NOS<7 were excluded. Evidence certainty was assessed with the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) method.

RESULTS

Thirty-four studies (n=26 cohorts and n=8 case-controls) were included. Of these, 32 assessed diabetes and all PC stages combined, 12 included early PC stages, and 15 included advanced PC stages. Our meta-analysis showed diabetes had a protective effect against early PC development (n=11, risk ratio [RR]=0.71; 95% confidence interval [CI]=0.61-0.83, I²=84%) but no association was found for combined (n=21, RR=0.95; 95% CI=0.79-1.13, I²=99%) or advanced PC stages (n=15, RR=0.96; 95% CI=0.77-1.18, I²=98%) at diagnosis. According to GRADE, the evidence certainty was very low.

CONCLUSIONS

Diabetes may be protective against early PC stages, yet evidence linking diabetes to risk across all stages, and advanced PC specifically, is less conclusive. High heterogeneity may partially explain discrepancy in findings and was mostly associated with study design, method used for PC diagnosis, and risk measures. Our results may aid risk stratification of males with diabetes and inform new approaches for PC screening in this group, especially considering the reduced sensitivity of prostate-specific antigen values for those with diabetes.

Diabetes Mellitus and Prostate Cancer Risk-A Systematic Review and Meta-Analysis

INTRODUCTION

Prostate cancer is the second most commonly diagnosed malignant tumor worldwide and poses a significant challenge to public health. This systematic review and meta-analysis aims to investigate the association between diabetes mellitus and the risk of developing prostate cancer.

METHODS

We conducted a search of PubMed, Embase, and the Cochrane Library from 1998 to 2024. The risk of bias within the included studies was assessed using the Newcastle-Ottawa Scale. The DerSimonian-Laird random-effect model was employed for the meta-analysis. Heterogeneity was evaluated using a forest plot and statistically assessed via the Q test, I2 index, and p-values.

RESULTS

Forty-three studies involving a total of 3,746,769 patients were included. Both case-control (pOR = 0.68, 95% CI: 0.61-0.97; I2 = 92.24%) and cohort studies (pRR = 0.71, 95% CI: 0.59-0.99; I2 = 85.41%) suggest that diabetes mellitus is associated with a reduced risk of prostate cancer, though with significant heterogeneity (p < 0.05). Subgroup analysis revealed that the risk of developing prostate cancer was significantly higher in patients with a family history of prostate cancer (pRR = 1.25, 95% CI: 1.16-1.35; I2 = 69.51%).

CONCLUSIONS

Our meta-analysis of recent observational studies indicates that diabetes mellitus is associated with a reduced risk of developing prostate cancer.

The effect of SGLT2 inhibition on prostate cancer: Mendelian randomization and observational analysis using electronic healthcare and cohort data

We evaluated the effect of sodium-glucose cotransporter 2 (SGLT2) inhibition on prostate cancer by evidence triangulation. Using Mendelian randomization, we found that genetically proxied SGLT2 inhibition reduced the risk of overall (odds ratio = 0.56, 95% confidence interval [CI] = 0.38 to 0.82; 79,148 prostate cancer cases and 61,106 controls), advanced, and early-onset prostate cancer. Using electronic healthcare data (nSGLT2i = 24,155; nDPP4i = 24,155), we found that the use of SGLT2 inhibitors was associated with a 23% reduced risk of prostate cancer (hazard ratio = 0.77, 95% CI = 0.61 to 0.99) in men with diabetes. Using data from two prospective cohorts (n4C = 57,779; nUK_Biobank = 165,430), we found little evidence to support the association of HbA1c with prostate cancer, implying a non-glycemic effect of SGLT2 inhibition on prostate cancer. In summary, this study provides multiple layers of evidence to support the beneficial effect of SGLT2 inhibition on reducing prostate cancer risk. Future trials are warranted to investigate whether SGLT2 inhibitors can be recommended for prostate cancer prevention.

Dietary insulin indices and low-carbohydrate diet and the odds of colorectal cancer: a case-control study

BACKGROUND

Regarding the role of insulin and insulin-inducing dietary factors in some cancers' etiology, we hypothesized that the risk of colorectal cancer may be lessened by following a lower carbohydrate and insulinogenic diet. Therefore, we performed this study to explore the association between a low-carbohydrate diet and insulin indices and the odds of colorectal cancer.

METHOD

This hospital-based case-control study was conducted on 150 newly diagnosed colorectal cancer patients and 300 healthy age- and sex-matched hospitalized controls. A valid and reliable food frequency questionnaire was used to calculate the insulin indices and low-carbohydrate diet score. Multivariate logistic regression was used to estimate the association between insulin indices and low-carbohydrate diet and the odds of colorectal cancer.

RESULT

After adjusting for potential confounders, individuals in the highest tertile of insulin indices had a higher risk of colorectal cancer (OR insulin index  = 3.46; 95% CI, 2.00-5.96; OR insulin load  = 2; 95% CI, 1.17-3.41). No association was found between a low-carbohydrate diet and colorectal cancer (OR = 1.55; 95% CI, 0.85-2.84).

CONCLUSION

Current results demonstrated that a high insulinemic diet was associated with a higher risk of colorectal cancer.

The association between diabetes mellitus and prostate cancer: a meta-analysis and Mendelian randomization

BACKGROUND

Prostate cancer is one of the most common types of cancer in the US, and it has a high mortality rate. Diabetes mellitus is also a dangerous health condition. While some studies have examined the relationship between diabetes mellitus and the risk of prostate cancer, there is still some debate on the matter. This study aims to carefully assess the relationship between prostate cancer and diabetes from both real-world and genetic-level data.

METHODS

This meta-analysis was conducted following the PRISMA 2020 reporting guidelines. The study searched three databases including Medline, Embase and Cochrane. The studies about the incidence risk of prostate cancer with diabetes mellitus were included and used to evaluate the association. The odds ratio (OR), risk ratio (RR) and 95% confidence intervals (95% CI) were estimated using Random Effects models and Fixed Effects models. Mendelian randomization study using genetic variants was also conducted.

RESULTS

A total of 72 articles were included in this study. The results showed that risk of prostate cancer decreased in diabetes patients. And the influence was different in different regions. This study also estimated the impact of body mass index (BMI) in the diabetes populations and found that the risk decreased in higher BMI populations. The MR analysis found that diabetes mellitus exposure reduced the risk of prostate cancer in the European population and Asia populations. Conclusions The diabetes mellitus has a protective effect on prostate cancer. And the influence of obesity in diabetes mellitus plays an important role in this effect.

Risk factors for prostate cancer: An umbrella review of prospective observational studies and mendelian randomization analyses

BACKGROUND

The incidence of prostate cancer is increasing in older males globally. Age, ethnicity, and family history are identified as the well-known risk factors for prostate cancer, but few modifiable factors have been firmly established. The objective of this study was to identify and evaluate various factors modifying the risk of prostate cancer reported in meta-analyses of prospective observational studies and mendelian randomization (MR) analyses.

METHODS AND FINDINGS

We searched PubMed, Embase, and Web of Science from the inception to January 10, 2022, updated on September 9, 2023, to identify meta-analyses and MR studies on prostate cancer. Eligibility criteria for meta-analyses were (1) meta-analyses including prospective observational studies or studies that declared outcome-free at baseline; (2) evaluating the factors of any category associated with prostate cancer incidence; and (3) providing effect estimates for further data synthesis. Similar criteria were applied to MR studies. Meta-analysis was repeated using the random-effects inverse-variance model with DerSimonian-Laird method. Quality assessment was then conducted for included meta-analyses using AMSTAR-2 tool and for MR studies using STROBE-MR and assumption evaluation. Subsequent evidence grading criteria for significant associations in meta-analyses contained sample size, P values and 95% confidence intervals, 95% prediction intervals, heterogeneity, and publication bias, assigning 4 evidence grades (convincing, highly suggestive, suggestive, or weak). Significant associations in MR studies were graded as robust, probable, suggestive, or insufficient considering P values and concordance of effect directions. Finally, 92 selected from 411 meta-analyses and 64 selected from 118 MR studies were included after excluding the overlapping and outdated studies which were published earlier and contained fewer participants or fewer instrument variables for the same exposure. In total, 123 observational associations (45 significant and 78 null) and 145 causal associations (55 significant and 90 null) were categorized into lifestyle; diet and nutrition; anthropometric indices; biomarkers; clinical variables, diseases, and treatments; and environmental factors. Concerning evidence grading on significant associations, there were 5 highly suggestive, 36 suggestive, and 4 weak associations in meta-analyses, and 10 robust, 24 probable, 4 suggestive, and 17 insufficient causal associations in MR studies. Twenty-six overlapping factors between meta-analyses and MR studies were identified, with consistent significant effects found for physical activity (PA) (occupational PA in meta: OR = 0.87, 95% CI: 0.80, 0.94; accelerator-measured PA in MR: OR = 0.49, 95% CI: 0.33, 0.72), height (meta: OR = 1.09, 95% CI: 1.06, 1.12; MR: OR = 1.07, 95% CI: 1.01, 1.15, for aggressive prostate cancer), and smoking (current smoking in meta: OR = 0.74, 95% CI: 0.68, 0.80; smoking initiation in MR: OR = 0.91, 95% CI: 0.86, 0.97). Methodological limitation is that the evidence grading criteria could be expanded by considering more indices.

CONCLUSIONS

In this large-scale study, we summarized the associations of various factors with prostate cancer risk and provided comparisons between observational associations by meta-analysis and genetically estimated causality by MR analyses. In the absence of convincing overlapping evidence based on the existing literature, no robust associations were identified, but some effects were observed for height, physical activity, and smoking.

Prognostic Factors in Prostate Cancer Associated with Ulcerative Colitis

Ulcerative colitis (UC) has been associated with increased prostate cancer (PCa) risk. However, the mechanisms underlying UC and increased PCa risk remain unclear, and research on this topic is scarce in Japan. We have investigated whether UC is associated with PCa risk in the Japanese population and the risk factors related to PCa among older UC patients. This retrospective single-center cohort study was conducted between January 2010 and April 2022. A total of 68 cases were analyzed, and 9 cases of PCa were observed (13.2%). PCa occurred more frequently in the adult-onset group (8/40, 20.0%) than in the older-onset group with UC (1/28; 3.57%). No significant differences were observed between immunosuppressive therapies and PCa in patients, excluding those with pancolitis-type UC. PCa occurred more frequently in the pancolitis type, and the biologics group had no PCa cases, but the difference was not statistically significant (p = 0.07). This study suggests that pancolitis type and UC onset in middle-aged patients may be risk factors and found that biologics potentially suppress PCa development.

A study on the relationship between malignancy and diabetes

BACKGROUND & AIMS

Today, malignancy and diabetes mellitus are important health problems with an increasing prevalence that have high morbidity and mortality. The purpose of this study was to examine the presence of overt diabetes mellitus (DM) in individuals with malignancy diagnosis, evaluate the effect of pre-diagnosis glucose control on the patients, DM duration and treatment options for malignancy development and type, and investigate the risk of DM development on non-diabetic patients with malignancy after cancer treatment.

METHODS

A total of 469 patients between the ages of 26 and 70 with different malignancies were divided into 3 groups. Group I: Patients with overt DM that were diagnosed before the malignancy diagnosis or diagnosed during the malignancy diagnosis (n = 97); Group II: Patients that developed DM during the malignancy (anticancer) treatment (n = 17), Group III: Non-diabetic patients with malignancy diagnosis (n = 355).

RESULTS

Group I participants were found to have the highest mean BMI value (33.2 ± 6.7 kg/m2) and lowest weekly physical activity duration (p < 0.05). While 28.8 % of the patients with overt DM before diagnosis were found not to be followed up for DM, 18.8 % were not using antidiabetic medication. A total of 29.4% of the patients who developed DM during the malignancy treatment were found to have pancreas surgery and 17.5 % had corticosteroid treatment.

CONCLUSIONS

Appropriate screening programs should be developed for diabetic patients, taking into account the common risk factors of cancer and DM. Also, oncological treatments in patients with malignancy may lead to the development of DM. Therefore, the effects of decided anticancer treatment on glucose metabolism should not be overlooked and glucose metabolism in the patient must be monitored regularly.

Type 2 Diabetes and Colorectal Cancer Risk

Importance

Type 2 diabetes and colorectal cancer (CRC) disproportionately burden indviduals of low socioeconomic status and African American race. Although diabetes is an emerging CRC risk factor, associations between diabetes and CRC in these populations are understudied.

Objective

To determine if diabetes is associated with CRC risk in a cohort representing understudied populations.

Design, Setting, and Participants

This cohort study uses data from the prospective Southern Community Cohort Study in the US, which recruited from 2002 to 2009 and completed 3 follow-up surveys by 2018. Of about 85 000 participants, 86% enrolled at community health centers, while 14% were enrolled via mail or telephone from the same 12 recruitment states. Participants with less than 2 years of follow-up, previous cancer diagnosis (excluding nonmelanoma skin cancer) at enrollment, missing enrollment diabetes status, diabetes diagnosis before age 30, and without diabetes at enrollment with no follow-up participation were excluded. Data were analyzed from January to September 2023.

Exposures

Physician-diagnosed diabetes and age at diabetes diagnosis were self-reported via survey at enrollment and 3 follow-ups.

Main Outcomes and Measures

Diabetes diagnosis was hypothesized to be positively associated with CRC risk before analysis. Incident CRC was assessed via state cancer registry and National Death Index linkage. Hazard ratios and 95% CIs were obtained via Cox proportional hazard models, using time-varying diabetes exposure.

Results

Among 54 597 participants, the median (IQR) enrollment age was 51 (46-58) years, 34 786 (64%) were female, 36 170 (66%) were African American, and 28 792 (53%) had income less than $15 000 per year. In total, 289 of 25 992 participants with diabetes developed CRC, vs 197 of 28 605 participants without diabetes. Diabetes was associated with increased CRC risk (hazard ratio [HR], 1.47; 95% CI, 1.21-1.79). Greater associations were observed among participants without colonoscopy screening (HR, 2.07; 95% CI, 1.16-3.67) and with smoking history (HR, 1.62; 95% CI, 1.14-2.31), potentially due to cancer screening differences. Greater associations were also observed for participants with recent diabetes diagnoses (diabetes duration <5 years compared with 5-10 years; HR, 2.55; 95% CI, 1.77-3.67), possibly due to recent screening.

Conclusions and Relevance

In this study where the majority of participants were African American with low socioeconomic status, diabetes was associated with elevated CRC risk, suggesting that diabetes prevention and control may reduce CRC disparities. The association was attenuated for those who completed colonoscopies, highlighting how adverse effects of diabetes-related metabolic dysregulation may be disrupted by preventative screening.

Association between diabetes at different diagnostic ages and risk of cancer incidence and mortality: a cohort study

Background

Different ages for diagnosis of diabetes have diverse effects on risks of cardiovascular disease, dementia, and mortality, but there is little evidence of cancer. This study investigated the relationship between diabetes at different diagnostic ages and risks of cancer incidence and mortality in people aged 37-73 years.

Methods

Participants with diabetes in the UK Biobank prospective cohort were divided into four groups: ≤40, 41-50, 51-60, and >60 years according to age at diagnosis. A total of 26,318 diabetics and 105,272 controls (1:4 randomly selected for each diabetic matched by the same baseline age) were included. We calculated the incidence density, standardized incidence, and mortality rates of cancer. Cox proportional hazard model was used to examine the associations of diabetes at different diagnostic ages with cancer incidence and mortality, followed by subgroup analyses.

Results

Compared to corresponding controls, standardized incidence and mortality rates of overall and digestive system cancers were higher in diabetes diagnosed at age 41-50, 51-60, and >60 years, especially at 51-60 years. Individuals diagnosed with diabetes at different ages were at higher risk to develop site-specific cancers, with a prominently increased risk of liver cancer since the diagnosis age of >40 years. Significantly, participants with diabetes diagnosed at 51-60 years were correlated with various site-specific cancer risks [hazard ratio (HR) for incidence: 1.088-2.416, HR for mortality: 1.276-3.269]. Moreover, for mortality of digestive system cancers, we observed an interaction effect between smoking and diabetes diagnosed at 51-60 years.

Conclusion

Our findings highlighted that the age at diagnosis of diabetes, especially 51-60 years, was critical risks of cancer incidence and mortality and may represent a potential preventative window for cancer.

The role of gut microbiota and drug interactions in the development of colorectal cancer

The human gut microbiota is a complex ecosystem regulating the host's environmental interaction. The same functional food or drug may have varying bioavailability and distinct effects on different individuals. Drugs such as antibiotics can alter the intestinal flora, thus affecting health. However, the relationship between intestinal flora and non-antibiotic drugs is bidirectional: it is not only affected by drugs; nevertheless, it can alter the drug structure through enzymes and change the bioavailability, biological activity, or toxicity of drugs to improve their efficacy and safety. This review summarizes the roles and mechanisms of antibiotics, antihypertensive drugs, nonsteroidal anti-inflammatory drugs, lipid-lowering drugs, hypoglycemic drugs, virus-associated therapies, metabolites, and dietary in modulating the colorectal cancer gut microbiota. It provides a reference for future antitumor therapy targeting intestinal microorganisms.

2022 Update on Prostate Cancer Epidemiology and Risk Factors-A Systematic Review

CONTEXT

Prostate cancer (PCa) is one of the most common cancers worldwide. Understanding the epidemiology and risk factors of the disease is paramount to improve primary and secondary prevention strategies.

OBJECTIVE

To systematically review and summarize the current evidence on the descriptive epidemiology, large screening studies, diagnostic techniques, and risk factors of PCa.

EVIDENCE ACQUISITION

PCa incidence and mortality rates for 2020 were obtained from the GLOBOCAN database of the International Agency for Research on Cancer. A systematic search was performed in July 2022 using PubMed/MEDLINE and EMBASE biomedical databases. The review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines and was registered in PROSPERO (CRD42022359728).

EVIDENCE SYNTHESIS

Globally, PCa is the second most common cancer, with the highest incidence in North and South America, Europe, Australia, and the Caribbean. Risk factors include age, family history, and genetic predisposition. Additional factors may include smoking, diet, physical activity, specific medications, and occupational factors. As PCa screening has become more accepted, newer approaches such as magnetic resonance imaging (MRI) and biomarkers have been implemented to identify patients who are likely to harbor significant tumors. Limitations of this review include the evidence being derived from meta-analyses of mostly retrospective studies.

CONCLUSIONS

PCa remains the second most common cancer among men worldwide. PCa screening is gaining acceptance and will likely reduce PCa mortality at the cost of overdiagnosis and overtreatment. Increasing use of MRI and biomarkers for the detection of PCa may mitigate some of the negative consequences of screening.

PATIENT SUMMARY

Prostate cancer (PCa) remains the second most common cancer among men, and screening for PCa is likely to increase in the future. Improved diagnostic techniques can help reduce the number of men who need to be diagnosed and treated to save one life. Avoidable risk factors for PCa may include factors such as smoking, diet, physical activity, specific medications, and certain occupations.

Prevalence of diabetes mellitus among 80,193 gastrointestinal cancer patients in five European and three Asian countries

Background

Diabetes mellitus (DM) has recently been associated with an increased incidence of such digestive tract malignancies as gastric or colorectal cancer. However, systematic data on the prevalence of DM among digestive tract cancer entities, especially in terms of geographic distributions, are lacking.

Methods

We used the Oncology Dynamics database (IQVIA) to identify a total of 80,193 patients with gastrointestinal (GI) cancer (5845 esophagus, 20,806 stomach, 38,138 colon, and 15,414 rectum cancer patients) from eight European and Asian countries.

Results

The overall prevalence of DM among all digestive tract cancer patients was 14.8% (11,866/80,193). In terms of cancer site, DM prevalence was highest in patients with colon (15.5%) or rectal (15.3%) cancer and lowest in patients with esophageal cancer (12.0%). Interestingly, we observed significant differences in DM prevalence between countries. Spain (27.8%, 31.3%) and South Korea (21.0%, 27.9%) had the highest prevalence of DM among gastric and colon cancer patients, while DM prevalence in esophageal (18.8%) and rectal (38.0%) cancer patients was highest in Germany.

Conclusion

Our data revealed a high prevalence of DM among digestive tract cancer patients in Europe and Asia, and showed that DM prevalence varies among digestive tract cancer sites as well as countries.

Metastatic colorectal cancer and type 2 diabetes: prognostic and genetic interactions

The present study was undertaken to analyze prognostic and genetic interactions between type 2 diabetes and metastatic colorectal cancer. Patients’ survival was depicted through the Kaplan–Meier product limit method. Prognostic factors were examined through the Cox proportional‐hazards regression model, and associations between diabetes and clinical‐pathologic variables were evaluated by the χ² test. In total, 203 metastatic colorectal cancer patients were enrolled. Lymph nodes (P = 0.0004) and distant organs (> 2 distant sites, P = 0.0451) were more frequently involved in diabetic patients compared with those without diabetes. Diabetes had an independent statistically significant negative prognostic value for survival. Highly selected patients with cancer and/or diabetes as their only illness(es) were divided into three groups: (a) seven oligo‐metastatic patients without diabetes, (b) 10 poly‐metastatic patients without diabetes, and (c) 12 poly‐metastatic diabetic patients. These groups of patients were genetically characterized through the Illumina NovaSeq 6000 (San Diego, CA, USA) platform and TruSigt™Oncology 500 kit, focusing on genes involved in diabetes and colorectal cancer. Gene variants associated with diabetes and cancer were more frequent in patients in group 3. We found that type 2 diabetes is a negative prognostic factor for survival in colorectal cancer. Diabetes‐associated gene variants could concur with malignancy, providing a rational basis for innovative models of tumor progression and therapy.

The Effects of Mesenchymal Stem Cell on Colorectal Cancer

Colorectal cancer (CRC) is a common malignant tumor of the gastrointestinal tract with nonobvious early symptoms and late symptoms of anemia, weight loss, and other systemic symptoms. Its morbidity and fatality rate are next only to gastric cancer, esophageal cancer, and primary liver cancer among digestive malignancies. In addition to the conventional surgical intervention, other therapies such as radiotherapy and chemotherapy and new treatment methods such as biologics and microbiological products have been introduced. As a promising cell therapy, mesenchymal stem cell (MSC) has attracted extensive research attention. MSCs are early undifferentiated pluripotent stem cells, which have the common features of stem cells, including self-replication, self-division, self-renewal, and multidirectional differentiation. MSCs come from a wide range of sources and can be extracted from a variety of tissues such as the bone marrow, umbilical cord, and fat. Current studies have shown that MSCs have a variety of biological functions such as immune regulation, tissue damage repair, and therapeutic effects on tumors such as CRC. This review outlines the overview of MSCs and CRC and summarizes the role of MSC application in CRC.