Diabetes Medication Use in Association with Survival among Patients of Breast, Colorectal, Lung, or Gastric Cancer

Metformin in combination with chemotherapy increases apoptosis in gastric cancer cells and counteracts senescence induced by chemotherapy

Gastric cancer (GC) is the fourth leading cause of cancer death in the world, and there is a demand for new therapeutic agents to treat GC. Metformin has been demonstrated to be an antineoplastic agent in some types of cancer; however, it has not been sufficiently valued in treating GC because the effect of metformin in combination with chemotherapy regimens has not yet been evaluated. The present study aimed to evaluate the mechanisms underlying cell death induced by metformin alone or when combined with chemotherapy. The cytogenetic characteristics of the NCI-N87 cell line were determined by fluorescence in situ hybridization (FISH). To determine viability, the cells were treated with metformin, epirubicin, cisplatin, docetaxel and 5-fluorouracil (individually and at different concentrations). Subsequently, the cells were treated with metformin alone, and in combination with the chemotherapeutic drugs and the epirubicin + cisplatin + 5-fluorouracil, docetaxel + cisplatin + 5-fluorouracil, and cisplatin + 5-fluorouracil regimens. Cell viability, proliferation and mitochondrial membrane potential (ΔΨm) were analyzed by spectrophotometry. Apoptosis, caspase activity and cell cycle progression were assessed by flow cytometry. Finally, light microscopy was used to evaluate senescence and clonogenicity. The results revealed that metformin, alone and when combined with chemotherapy, increased the proportion of apoptotic cells, promoted the loss of ΔΨm, and induced apoptosis through caspase activity in GC cells. Moreover, metformin decreased cell proliferation. In addition, metformin alone did not induce senescence and it counteracted the effects of chemotherapy-induced senescence in GC cells. Additionally, metformin, alone and when combined with chemotherapy, decreased the clonogenic capacity of NCI-N87 GC cells. In conclusion, metformin may increase the effects of chemotherapy on NCI-N87 cell death and could represent an option to improve the treatment of GC.

Association of metformin and statin uses with the prognosis of colon cancer: a meta-analysis

BACKGROUND

Metformin and statins are commonly used globally for the treatment of type 2 diabetes mellitus and dyslipidemia, respectively. Recently, multiple novel pathways have been discovered, which may contribute to the treatment of various types of cancer. Several meta-analysis studies have reported that the use of metformin or statins is associated with a lower risk of colon cancer compared to nonusers. In this study, our aim was to perform a meta-analysis and investigate the prognostic roles of these two medications in colon cancer.

METHODS

To identify relevant articles, literature searches were performed in the PubMed and Web of Science databases using a combination of keywords related to metformin, statins and colon cancer prognosis until August 2023. The study utilized STATA 12.0 software (Stata Corporation, College Station, Texas, USA) to compute all the hazard ratios (HRs) and 95% confidence intervals (CIs) regarding the association between metformin or statin uses and prognostic-related outcomes.

RESULTS

Our analysis revealed that the use of metformin was associated with a significantly lower overall mortality of colon cancer (HR = 0.63; 95% CI = 0.51-0.77; I2  = 94.9%; P  < 0.001), as well as lower cancer-specific mortality of colon cancer (HR = 0.68; 95% CI = 0.50-0.94; I2  = 91.9%; P  < 0.001). Similarly, the use of statins was also associated with a lower overall mortality of colon cancer (HR = 0.68; 95% CI = 0.60-0.78; I2  = 93.8%; P  < 0.001), as well as a lower cancer-specific mortality of colon cancer (HR = 0.74; 95% CI = 0.67-0.81; I2  = 82.2%; P  < 0.001).

CONCLUSION

Our meta-analysis study suggests that statins and metformin may have potential as adjuvant agents with significant benefits in the prognosis of colon cancer.

Effect of Metformin Use on Survival and Recurrence Rate of Gastric Cancer After Gastrectomy in Diabetic Patients: A Systematic Review and Meta-analysis of Observational Studies

BACKGROUND

Gastric cancer (GC) is one of the most common worldwide cancers and causes of death. Various studies have investigated the effect of metformin on overall survival (OS), cancer-specific survival (CSS), recurrence-free survival (RFS), and recurrence rate in diabetic patients after gastrectomy, and their results have been contradictory. This meta-analysis aimed to evaluate the effect of metformin use compared to sulfonylurea compounds with OS, CSS, RFS, and recurrence rate after gastrectomy in diabetic patients.

METHODS

We reviewed the Scopus, Google Scholar, PubMed, Web of Science, and Embassy databases until September 2022 based on appropriate MESH terms. All observational studies that evaluated the effect of metformin on survival in diabetic patients who underwent surgery for GC were included. The hazard ratio (HR) with a 95% confidence interval was used to estimate the effect size. The Egger test was used to evaluate publication bias.

RESULTS

Overall, nine studies, including 245,387 GC patients who underwent surgery, were included. The use of metformin significantly increased the OS rate (HR: 0.81, 95% CI: 0.78, 0.86, P: 0.001, I2: 4.5%), CSS rate (HR: 0.72, 95% CI: 0.63, 0.81, P: 0.011, I2 = 0%), and RFS rate (HR: 719, 95% CI: 0.524, 0.986, P: 0.001) and decreased the recurrence rate after gastrectomy (HR: 0.83, 95% CI: 0.77, 0.87, P: 0.001, I2: 0%). The use of metformin was significantly associated with a greater increase in OS and CSS rate and a greater decrease in recurrence rate in the Asian population than in the Western population.

CONCLUSION

The use of metformin in diabetic patients with GC can be associated with improved OS, CSS, RFS, and reduced recurrence rate after gastrectomy, especially in the Asian population.

Antidiabetic Drugs in Breast Cancer Patients

Diabetes is one of the leading chronic conditions worldwide, and breast cancer is the most prevalent cancer in women worldwide. The linkage between diabetes and its ability to increase the risk of breast cancer should always be analyzed in patients. This review focuses on the impact of antihyperglycemic therapy in breast cancer patients. Patients with diabetes have a higher risk of developing cancer than the general population. Moreover, diabetes patients have a higher incidence and mortality of breast cancer. In this review, we describe the influence of antidiabetic drugs from insulin and metformin to the current and emerging therapies, incretins and SGLT-2 inhibitors, on breast cancer prognosis. We also emphasize the role of obesity and the metastasis process in breast cancer patients who are treated with antidiabetic drugs.

Diabetes Mellitus and Gastric Cancer: Correlation and Potential Mechanisms

This review summarizes the correlation between diabetes mellitus (DM) and gastric cancer (GC) from the perspectives of epidemiology, drug use, and potential mechanisms. The association between DM and GC is inconclusive, and the positive direction of the association reported in most published meta-analyses suggests that DM may be an independent risk factor for GC. Many clinical investigations have shown that people with DM and GC who undergo gastrectomy may have better glycemic control. The potential link between DM and GC may involve the interaction of multiple common risk factors, such as obesity, hyperglycemia and hyperinsulinemia, H. pylori infection, and the use of metformin. Although in vitro and in vivo data support that H. pylori infection status and metformin can influence GC risk in DM patients, there are conflicting results. Patient survival outcomes are influenced by multiple factors, so further research is needed to identify the patients who may benefit.

Shared Lifestyle-Related Risk Factors of Cardiovascular Disease and Cancer: Evidence for Joint Prevention

Cardiovascular disease (CVD) and cancer are leading causes of mortality and morbidity worldwide and are the major focus of the World Health Organization's joint prevention programs. While, diverse diseases, CVD and cancer, have many similarities. These include common lifestyle-related risk factors and shared environmental, metabolic, cellular, inflammatory, and genetic pathways. In this review, we will discuss the shared lifestyle-related and environmental risk factors central to both diseases and how the strategies commonly used to prevent atherosclerotic vascular disease can be applied to cancer prevention.

Metformin induces autophagy of cisplatin-resistant human gastric cancer cells in addition to apoptosis

Metformin has been used to treat cases of type 2 diabetes mellitus, and mounting studies have shown that metformin can act alone or in synergy with other anticancer agents to achieve anti-cancer efficacies on various types of tumors. However, the role of metformin in either inducing autophagy and cisplatin-resistance of human gastric cancer (GC) cells has never been examined. The study has established a cisplatin-resistant GC cell line and investigated the effects of metformin on inducing autophagy on it. The results demonstrated that treatment with metformin can concentration-dependently suppress the cell viability and cell confluence of cisplatin-resistant GC cells, while having no effects on human primary stomach epithelial cells (HPSEC). For the first time, we found that metformin can significantly increase the acidic vesicular organelles (AVO) level and decrease the acridine orange (AO) level spontaneously in the cisplatin-resistant GC cells. Thus, we further checked the other markers, Atg5, Atg12 and LC3-II, which showed that metformin indeed induced autophagy in the cisplatin-resistant GC cells. In addition, treatment of 3-Methyladenine (3-MA) can significantly rescue the metformin-induced autophagy. At the same time, metformin can induce the alterations of apoptosis-associated signal molecules, such as caspase-3 and caspase-7 activities. Overall, the pilot study provided evidence for metformin induced autophagy in addition to apoptosis, making it as an effective anticancer drug for the therapy of cisplatin-resistant GC. Killing the cisplatin-resistant GC cells with non-toxic metformin via both autophagy and apoptosis might extend its usefulness in our fighting with chemo-resistance of gastric cancer cells.

A Mathematical Model of the Disruption of Glucose Homeostasis in Cancer Patients

In this paper, we investigate the disruption of the glucose homeostasis at the whole-body level by the presence of cancer disease. Of particular interest are the potentially different responses of patients with or without hyperglycemia (including diabetes mellitus) to the cancer challenge, and how tumor growth, in turn, responds to hyperglycemia and its medical management. We propose a mathematical model that describes the competition between cancer cells and glucose-dependent healthy cells for a shared glucose resource. We also include the metabolic reprogramming of healthy cells by cancer-cell-initiated mechanism to reflect the interplay between the two cell populations. We parametrize this model and carry out numerical simulations of various scenarios, with growth of tumor mass and loss of healthy body mass as endpoints. We report sets of cancer characteristics that show plausible disease histories. We investigate parameters that change cancer cells' aggressiveness, and we exhibit differing responses in diabetic and non-diabetic, in the absence or presence of glycemic control. Our model predictions are in line with observations of weight loss in cancer patients and the increased growth (or earlier onset) of tumor in diabetic individuals. The model will also aid future studies on countermeasures such as the reduction of circulating glucose in cancer patients.

A mathematical model of the disruption of glucose homeostasis in cancer patients

In this paper we investigate the disruption of the glucose homeostasis at the whole-body level by the presence of cancer disease. Of particular interest are the potentially different responses of patients with or without hyperglycemia (including Diabetes Mellitus) to the cancer challenge, and how tumor growth, in turn, responds to hyperglycemia and its medical management. We propose a mathematical model that describes the competition between cancer cells and glucosedependent healthy cells for a shared glucose resource. We also include the metabolic reprogramming of healthy cells by cancer-cell-initiated mechanism to reflect the interplay between the two cell populations. We parametrize this model and carry out numerical simulations of various scenarios, with growth of tumor mass and loss of healthy body mass as endpoints. We report sets of cancer characteristics that show plausible disease histories. We investigate parameters that change cancer cells’ aggressiveness, and we exhibit differing responses in diabetic and non-diabetic, in the absence or presence of glycemic control. Our model predictions are in line with observations of weight loss in cancer patients and the increased growth (or earlier onset) of tumor in diabetic individuals. The model will also aid future studies on countermeasures such as the reduction of circulating glucose in cancer patients.

Effect of Metformin on the Prognosis of Gastric Cancer Patients with Type 2 Diabetes Mellitus: A Meta-Analysis Based on Retrospective Cohort Studies

BACKGROUND

Metformin is one of the most common drugs for type 2 diabetes mellitus (T2DM) treatment. In addition, metformin intends to have a positive effect on the prognosis of several cancers. However, the therapeutic effect of metformin on gastric cancer (GC) remains controversial. This study explores and updates the therapeutic effect of metformin in GC patients with T2DM.

METHODS

We searched through PubMed, Embase, Web of Science, and the Cochrane Library for relevant articles by July 2022. The relationship between metformin therapy and the prognosis of GC patients with T2DM was evaluated based on the hazard ratio (HR) at a 95% confidence interval (95% CI). Overall survival (OS), cancer-specific survival (CSS), and progression-free survival (PFS) were the primary outcomes analyzed.

RESULTS

Seven retrospective cohort studies with a combined 2,858 patients met the inclusion criteria. OS and CSS were reported in six studies, and PFS was reported in four studies. Pooled results showed that, compared to the nonmetformin group, the prolonged OS (HR = 0.72, p = 0.001), CSS (HR = 0.81, p = 0.001), and PFS (HR = 0.70, p = 0.008) of the experimental group may be associated with the exposure to metformin.

CONCLUSION

Metformin may have a beneficial effect on the prognosis of GC patients with T2DM.

The Association of Metformin, Other Antidiabetic Medications and Statins on the Prognosis of Rectal Cancer in Patients with Type 2 Diabetes: A Retrospective Cohort Study

Metformin and statin use have been associated with an improved prognosis for colorectal cancer in persons with type 2 diabetes (T2D). Data regarding rectal cancer (RC) have been inconclusive; therefore, we investigated the issue with high-quality data and a robust study design. We identified 1271 eligible patients with T2D and incident RC between 1998 and 2011 from the Diabetes in Finland (FinDM) database. Cox models were fitted for cause-specific mortality rates to obtain adjusted estimates of the hazard ratios (HR) with 95% confidence intervals (CI) in relation to use of antidiabetic medication (ADM) and statins before the RC diagnosis and for post-diagnostic use in a time-dependent exposure manner. No sufficient evidence was found for either pre- or post-diagnostic metformin use and RC mortality (HR 0.96, 95% CI 0.67–1.38, and 0.70, 95% CI 0.45–1.10, respectively) when compared to other oral ADMs. Both pre- and post-diagnostic statin use appeared to be inversely associated with mortality from RC (HR 0.77 95% CI 0.63–0.94, and 0.57, 95% CI 0.42–0.78, respectively). Our study was inconclusive as to the association of metformin use with the prognosis of RC, but statin use was found to predict reduced mortality, both from RC and from other causes of death in persons with T2D.

Systemic Evaluation of the Effect of Diabetes Mellitus on Breast Cancer in a Mouse Model

Breast cancer complicated with diabetes mellitus (DM) is a common disease. To evaluate the effect of preexisting DM on breast cancer progression without drug interference, we used a streptozotocin (STZ)-induced type 2 diabetes mellitus BALB/c mouse model. We found that 4T1 breast cancer complicated with DM decreased the mouse survival time compared with 4T1-bearing mice. The diversity of gut microbiome was affected by DM. The infiltration of mucosal-associated invariant T cell (MAIT), CD8+ T cell, and CD4+ T cell in the tumor was significantly decreased in the DM-4T1 group compared with the 4T1 group. The transcriptome data of tumor tissues indicated that the expressions of inflammatory C–C chemokine- and metabolism-related genes were greatly changed. The abnormal expression of these genes may be related with the decreased T-cell infiltration in DM-4T1. In conclusion, the gut microbiome and tumor microenvironment of diabetic breast cancer patients have unique features. The effect of diabetes on breast cancer should be considered in the treatment for diabetic breast cancer patients.

Diabetes and Colorectal Cancer Risk: Clinical and Therapeutic Implications

Several epidemiological studies have identified diabetes as a risk factor for colorectal cancer (CRC). The potential pathophysiological mechanisms of this association include hyperinsulinemia, insulin-like growth factor (IGF) axis, hyperglycemia, inflammation induced by adipose tissue dysfunction, gastrointestinal motility disorder, and impaired immunological surveillance. Several studies have shown that underlying diabetes adversely affects the prognosis of patients with CRC. This review explores the novel anticancer agents targeting IGF-1R and receptor for advanced glycation end products (RAGE), both of which play a vital role in diabetes-induced colorectal tumorigenesis. Inhibitors of IGF-1R and RAGE are expected to become promising therapeutic choices, particularly for CRC patients with diabetes. Furthermore, hypoglycemic therapy is associated with the incidence of CRC. Selection of appropriate hypoglycemic agents, which can reduce the risk of CRC in diabetic patients, is an unmet issue. Therefore, this review mainly summarizes the current studies concerning the connections among diabetes, hypoglycemic therapy, and CRC as well as provides a synthesis of the underlying pathophysiological mechanisms. Our synthesis provides a theoretical basis for rational use of hypoglycemic therapies and early diagnosis and treatment of diabetes-related CRC.

Progress in understanding of relationship between diabetes and colorectal cancer

Several epidemiological studies have suggested that diabetes is closely associated with an increased risk of colorectal cancer and diabetes could be regarded as an independent risk factor for colorectal cancer. Potential pathophysiological mechanisms connecting diabetes and colorectal cancer include hyperglycemia, hyperinsulinemia, and insulin-like growth factor axis, chronic inflammation and oxidative stress, gastrointestinal motility disorder, and impaired immunological surveillance. Meanwhile, multiple studies have revealed that diabetes is negatively related to the prognosis of patients with colorectal cancer. This review mainly summarizes the current studies concerning the linkages between diabetes and colorectal cancer and the underlying pathophysiological mechanisms, so as to provide a theoretical basis for rational use of antidiabetic drugs and early diagnosis of diabetes-related colorectal cancer.

Type 2 Diabetes and all-cause mortality among Spanish women with breast cancer

PURPOSE

To explore the effect of type 2 diabetes mellitus (T2DM) on the risk of death among women with breast cancer (BC).

METHODS

A survival analysis was conducted among a cohort of women diagnosed with BC between 2006 and 2012 in Spain (n = 4,493). Biopsy or surgery confirmed BC cases were identified through the state population-based cancer registry with information on patients' characteristics and vital status. Physician-diagnosed T2DM was confirmed based on primary health care clinical history. Cox regression analyses were used to estimate adjusted hazard ratios (aHR) and 95% confidence intervals (CI) for all-cause death. Analyses were adjusted for age, hospital size, several clinical characteristics (including BC stage and histology, among others) and treatment modalities.

RESULTS

Among the 4,493 BC women, 388 (8.6%) had coexisting T2DM. Overall, 1,299 (28.9%) BC women died during the completion of the follow-up and 785 (17.5%) did so during the first five years after BC diagnosis, resulting in a five-year survival rate of 82.5%. The death rate was higher in women with T2DM (43.8% died during whole period and 26.0% during the first five years) when compared with women without T2DM (27.5% and 16.7%, respectively). Accordingly, all-cause mortality was higher in women with T2DM (aHR: 1.22; 95% CI 1.03-1.44), especially if T2DM was diagnosed before BC (aHR:1.24; 95% CI 1.03-1.50) and in women with BC diagnosed before 50 years (aHR: 2.38; 95% CI 1.04-5.48).

CONCLUSIONS

T2DM was associated with higher all-cause mortality among Spanish women with BC, particularly when the T2DM diagnosis was prior to the BC.

Perspectives of metformin use in endometrial cancer and other gynaecological malignancies

Insulin resistance and hyperinsulinemia play a key role in type 1 endometrial cancer pathogenesis. Most of these cancers develop on a background of overweight or type 2 diabetes mellitus (T2DM). One of the medications widely used in the treatment of T2DM is biguanide derivative, metformin, which exerts promising anticancer properties principally through activation of adenosine monophosphate kinase (AMPK) and inhibition of mammalian target of rapamycin (mTOR) pathways. Many epidemiological studies on diabetic patients show potential preventative role of metformin in endometrial cancer patients, but data regarding its therapeutic role is still limited. So far, most of attention has been paid to the concept of metformin use in fertility sparing treatment of early-stage cancer. Another investigated alternative is its application in patients with primary advanced or recurrent disease. In this review we present the latest data on clinical use of metformin in endometrial cancer patients and potential underlying mechanisms of its activity. Finally, we present some most important clinical information regarding metformin efficacy in other gynaecological malignancies, mainly breast and ovarian cancer.

Potential intrinsic subtype dependence on the association between metformin use and survival in surgically resected breast cancer: a Korean national population-based study

PURPOSE

Numerous studies have suggested that metformin treatment can increase breast cancer survival; however, it is unclear whether its effects interact with intrinsic subtype or diabetic status. Therefore, we conducted a large nationwide study to assess this in women with surgically resected invasive breast cancer.

METHODS

Patients with newly diagnosed breast cancer between 2007 and 2016 were identified using the national health insurance claims database of South Korea. Metformin or other drug exposures was defined as medication for ≥ 90 days. Breast cancer subtypes were classified into four groups based on hormonal therapy and anti-HER2 treatments.

RESULTS

A total of 117,333 patients were included (median follow-up duration, 90 months). Type 2 diabetes mellitus (T2DM) affected significantly overall survival (OS, 7 years, 89.7% vs. 92.4%, p < 0.001). A significant interaction was found between the use of metformin and insulin in patients with T2DM (p = 0.018). Thus, the subsequent analysis was limited to these patients and propensity score matching was performed. We found significantly increased OS in patients treated with metformin (7-year OS, 88.3% vs. 85.6%, p < 0.001). Interestingly, a significant effect was observed in the hormonal therapy (HT)+/HER2-targeted therapy (Tx)- group (p < 0.001), whereas no specific association was observed in the HT-/HER2 Tx- group (p = 0.220).

CONCLUSIONS

Metformin administration may be associated with reduced mortality in patients with surgically resected breast cancer, particularly in the HT+/HER2 Tx- group. Clinical trials investigating metformin as a combination agent in breast cancer should stratify patients by curative resection, intrinsic subtype, the presence of T2DM, and the use of insulin.

Improved prognosis in gastric adenocarcinoma among metformin users in a population-based study

BACKGROUND

Metformin may improve the prognosis in gastric adenocarcinoma, but the existing literature is limited and contradictory.

METHODS

This was a Swedish population-based cohort study of diabetes patients who were diagnosed with gastric adenocarcinoma in 2005-2018 and followed up until December 2019. The data were retrieved from four national health data registries: Prescribed Drug Registry, Cancer Registry, Patient Registry and Cause of Death Registry. Associations between metformin use before the gastric adenocarcinoma diagnosis and the risk of disease-specific and all-cause mortality were assessed using multivariable Cox proportional hazard regression. The hazard ratios (HRs) and 95% confidence intervals (CIs) were adjusted for sex, age, calendar year, comorbidity, use of non-steroidal anti-inflammatory drugs or aspirin, and use of statins.

RESULTS

Compared with non-users, metformin users had a decreased risk of disease-specific mortality (HR 0.79, 95% CI 0.67-0.93) and all-cause mortality (HR 0.78, 95% CI 0.68-0.90). The associations were seemingly stronger among patients of female sex (HR 0.66, 95% CI 0.49-0.89), patients with tumour stage III or IV (HR 0.71, 95% CI 0.58-0.88), and those with the least comorbidity (HR 0.71, 95% CI 0.57-0.89).

CONCLUSIONS

Metformin use may improve survival in gastric adenocarcinoma among diabetes patients.

The Relationship between Diabetes Mellitus and Gastric Cancer and the Potential Benefits of Metformin: An Extensive Review of the Literature

The objective of this review is to summarize the findings of published research that investigated the relationship between diabetes mellitus and gastric cancer (GCa) and the potential benefits of metformin on GCa. Related literature has been extensively reviewed, and findings from studies investigating the relationship between diabetes mellitus and GCa suggest that hyperglycemia, hyperinsulinemia and insulin resistance are closely related to the development of GCa. Although not supported by all, most observational studies suggest an increased risk of GCa in patients with type 2 diabetes mellitus, especially in women and in Asian populations. Incidence of second primary malignancy diagnosed after GCa is significantly higher in diabetes patients. Diabetes patients with GCa may have more complications after gastrectomy or chemotherapy and they may have a poorer prognosis than patients with GCa but without diabetes mellitus. However, glycemic control may improve in the diabetes patients with GCa after receiving gastrectomy, especially after procedures that bypass the duodenum and proximal jejunum, such as Roux-en-Y gastric bypass or Billroth II reconstruction. The potential links between diabetes mellitus and GCa may involve the interactions with shared risk factors (e.g., obesity, hyperglycemia, hyperinsulinemia, insulin resistance, high salt intake, smoking, etc.), Helicobacter pylori (HP) infection, medications (e.g., insulin, metformin, statins, aspirin, proton pump inhibitors, antibiotics, etc.) and comorbidities (e.g., hypertension, dyslipidemia, vascular complications, heart failure, renal failure, etc.). With regards to the potential benefits of metformin on GCa, results of most observational studies suggest a reduced risk of GCa associated with metformin use in patients with T2DM, which can be supported by evidence derived from many in vitro and animal studies. Metformin use may also reduce the risk of HP infection, an important risk factor of GCa. In patients with GCa, metformin users may have improved survival and reduced recurrence. More studies are required to clarify the pathological subtypes/anatomical sites of GCa associated with type 2 diabetes mellitus or prevented by metformin, to confirm whether GCa risk can also be increased in patients with type 1 diabetes mellitus and to explore the possible role of gastric microbiota in the development of GCa.

Repurposing metformin for the treatment of gastrointestinal cancer

Diabetes mellitus type 2 and cancer share many risk factors. The pleiotropic insulin-dependent and insulin-independent effects of metformin might inhibit pathways that are frequently amplified in neoplastic tissue. Particularly, modulation of inflammation, metabolism, and cell cycle arrest are potential therapeutic cancer targets utilized by metformin to boost the anti-cancer effects of chemotherapy. Studies in vitro and in vivo models have demonstrated the potential of metformin as a chemo- and radiosensitizer, besides its chemopreventive and direct therapeutic activity in digestive system (DS) tumors. Hence, these aspects have been considered in many cancer clinical trials. Case-control and cohort studies and associated meta-analyses have evaluated DS cancer risk and metformin usage, especially in colorectal cancer, pancreatic cancer, and hepatocellular carcinoma. Most clinical studies have demonstrated the protective role of metformin in the risk for DS cancers and survival rates. On the other hand, the ability of metformin to enhance the actions of chemotherapy for gastric and biliary cancers is yet to be investigated. This article reviews the current findings on the anti-cancer mechanisms of metformin and its apparatus from pre-clinical and ongoing studies in DS malignancies.

Pharmacological inhibition of tumor anabolism and host catabolism as a cancer therapy

The malignant energetic demands are satisfied through glycolysis, glutaminolysis and de novo synthesis of fatty acids, while the host curses with a state of catabolism and systemic inflammation. The concurrent inhibition of both, tumor anabolism and host catabolism, and their effect upon tumor growth and whole animal metabolism, have not been evaluated. We aimed to evaluate in colon cancer cells a combination of six agents directed to block the tumor anabolism (orlistat + lonidamine + DON) and the host catabolism (growth hormone + insulin + indomethacin). Treatment reduced cellular viability, clonogenic capacity and cell cycle progression. These effects were associated with decreased glycolysis and oxidative phosphorylation, leading to a quiescent energetic phenotype, and with an aberrant transcriptomic landscape showing dysregulation in multiple metabolic pathways. The in vivo evaluation revealed a significant tumor volume inhibition, without damage to normal tissues. The six-drug combination preserved lean tissue and decreased fat loss, while the energy expenditure got decreased. Finally, a reduction in gene expression associated with thermogenesis was observed. Our findings demonstrate that the simultaneous use of this six-drug combination has anticancer effects by inducing a quiescent energetic phenotype of cultured cancer cells. Besides, the treatment is well-tolerated in mice and reduces whole animal energetic expenditure and fat loss.

Does Roux-en-Y Construction Really Bring Benefit of Type 2 Diabetes Mellitus Remission After Gastrectomy in Patients with Gastric Cancer? A Systematic Review and Meta-Analysis

INTRODUCTION

To evaluate whether the extent of gastrectomy or the reconstruction method brings benefit of type 2 diabetes mellitus (T2DM) remission after gastrectomy in patients with gastric cancer.

METHODS

PUBMED, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library were searched to find eligible studies published from inception to July 31, 2020.

RESULTS

A total of nine studies (1424 patients) were included. At the first year and the end of follow-up time after gastrectomy, the total gastrectomy group had better T2DM remission than the subtotal gastrectomy group, and the Roux-en-Y reconstruction (R-Y) group had better T2DM remission compared with the non-R-Y group. There was no difference between R-Y and non-R-Y in terms of subtotal gastrectomy (OR 1.08, 95% CI 0.63-1.84, P = 0.78). However, total gastrectomy with R-Y had better T2DM remission than subtotal gastrectomy with R-Y (OR 2.75, 95% CI 1.19-6.35, P = 0.02).

CONCLUSION

Total gastrectomy with R-Y had better T2DM remission. The extent of gastrectomy rather than the reconstruction method might play an important role in T2DM remission after gastrectomy in patients with gastric cancer.

Effects of hyperinsulinemia on acquired resistance to epidermal growth factor receptor-tyrosine kinase inhibitor via the PI3K/AKT pathway in non-small cell lung cancer cells in vitro

Patients with lung cancer harboring activating epidermal growth factor (EGFR) mutations and pre-existing diabetes have been demonstrated to exhibit poor responses to first-line EGFR-tyrosine kinase inhibitor (TKI) therapy. Strategies for the management of acquired resistance to EGFR-TKIs in patients with advanced non-small cell lung cancer (NSCLC) are urgently required. Only a limited number of studies have been published to date on the effects of insulin on EGFR-TKI resistance in NSCLC. Hence, the aim of the present study was to investigate the roles of hyperinsulinemia and hyperglycemia in mediating gefitinib resistance in NSCLC cells with activating EGFR mutations. In the present study, the HCC4006 cell line, which harbors EGFR mutations, was co-treated with gefitinib and long-acting insulin glargine. Whether hyperinsulinemia is able to mediate EGFR-TKI resistance in the NSCLC cell line harboring activating EGFR mutations was also investigated, and the possible underlying mechanisms responsible for these actions were explored. The inhibition of cell proliferation, and the potential mechanism of gefitinib resistance, were examined using an MTS proliferation assay and western blot analysis, and through the transfection of siRNAs. Whether the inhibition of AKT is able to overcome EGFR-TKI resistance induced by long-acting insulin was also investigated. The results obtained suggested that hyperinsulinemia induced by glargine upregulated NSCLC cell proliferation and survival, and induced gefitinib resistance. By contrast, the morphology and proliferation of the cells in a medium containing a 2-fold concentration of glucose were not significantly affected. Gefitinib resistance induced by hyperinsulinemia may have been mediated via the phosphoinositide 3-kinase (PI3K)/AKT pathway rather than the mitogen-activated protein kinase extracellular signal regulated kinase (MAPK/ERK) pathway. AKT serine/threonine kinase 1 knockdown by siRNA rescued the gefitinib resistance that was induced by hyperinsulinemia. In conclusion, hyperinsulinemia, but not hyperglycemia, was identified to cause the development of gefitinib resistance in NSCLC cells with activating EGFR mutations. However, additional studies are required to investigate strategies, such as co targeting hyperinsulinemia and the PI3K/AKT pathway, for overcoming EGFR-TKI resistance in patients with NSCLC.

Preventative and Therapeutic Effects of Metformin in Gastric Cancer: A New Contribution of an Old Friend

Gastric cancer (GC) is a cancer with high prevalence, and is one of the leading causes of cancer death worldwide. Metformin is a widely used hypoglycemic agent for type-2 diabetes mellitus (T2DM). Recently, metformin has drawn increasing attention in the field of cancer research for its emerging anti-cancer roles. However, the efficacy and underlying molecular mechanisms of metformin in the prevention and treatment for GC remain controversial. This review summarized the present clinical and mechanistic studies that investigated the efficacy of metformin in GC. It was found that the majority of clinical studies affirmed protective roles of metformin in both gastric cancer risk and survival rate. In addition, metformin’s effects in the prevention and treatment for GC involve multiple pathways mainly via AMPK and IGF-1R. It was concluded that metformin presents a unique opportunity for application against GC, but further clinical and mechanistic investigations are required to solidify the roles of metformin in GC.

Metformin protects against diabetes-induced heart injury and dunning prostate cancer model

In this study, both diabetes and Dunning prostate cancer were induced for the first time in Copenhagen rats in vivo. Thus, the effects of metformin against heart tissue damage of these rats were investigated by biochemical methods. Dunning prostate cancer was induced in Copenhagen rats using high metastatic MAT-LyLu cells. The rats were divided as follows: Control group: only injected with 0.9% NaCl for 14 days; Diabetic group: only injected single dose of streptozotocin (STZ) (65 mg/kg); Cancer group: subcutaneously (s.c) inoculated with 2 x 10⁴ MAT-LyLu cells only; Diabetic + cancer (DC) group: inoculated with 2 x 10⁴ MAT-LyLu cells and STZ injection, Cancer + metformin (CM) group: injected with metformin for 14 days after Mat-LyLu cells application; Diabetic + cancer + metformin (DCM) group: metformin administered for 14 days together with STZ and Mat-LyLu cells. At the end of the experimental period, heart tissues were taken. Reduced glutathione and total antioxidant status levels in heart tissues were decreased, whereas lipid peroxidation, advanced oxidized protein products, nitric oxide, homocysteine, and reactive oxygen species levels, total oxidant status and catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase, glutathione-S-transferase, alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase and xanthine oxidase activities increased in the diabetic, cancer and DC groups. Treatment with metformin reversed these effects. In conclusion, the present study shows that metformin has a protective effect against heart tissue damage in STZ-induced diabetic rats with Dunning prostate cancer.

The combination of orlistat, lonidamine and 6-diazo-5-oxo-L-norleucine induces a quiescent energetic phenotype and limits substrate flexibility in colon cancer cells

Cancer upregulates glycolysis, glutaminolysis and lipogenesis, and induces a catabolic state in patients. The concurrent inhibition of both tumor anabolism and host catabolism, and the energetic consequences of such an approach, have not previously been fully investigated. In the present study, CT26.WT murine colon cancer cells were treated with the combination of anti-anabolic drugs orlistat, lonidamine and 6-diazo-5-oxo-L-norleucine (DON; OLD scheme), which are inhibitors of the de novo synthesis of fatty acids, glycolysis and glutaminolysis, respectively. In addition, the effects of OLD scheme sumplemented with the combination of anti-catabolic compounds, namely growth hormone, insulin and indomethacin (GII scheme), were also evaluated. The effects of the compounds used in combination on CT26.WT cell viability, clonogenicity and energetic metabolism were assessed in vitro. The results demonstrated that the anti-anabolic approach reduced cell viability, clonogenicity and cell cycle progression, and increased apoptosis. These effects were associated with decreased oxidative phosphorylation, glycolysis and fuel flexibility. Furthermore, the anti-catabolic scheme, alone or supplemented with anti-anabolic compounds, did not favor tumor growth. These findings indicated that the simultaneous pharmacological inhibition of tumor anabolism and host catabolism exhibits antitumor effects that should be further evaluated.

Prognosis of Patients with Colorectal Cancer with Diabetes According to Medication Adherence: A Population-Based Cohort Study

BACKGROUND

Diabetes mellitus is known to have a negative effect on colorectal cancer survival due to hyperinsulinemia or hyperglycemia, and medications such as metformin, which targets insulin resistance and hyperinsulinemia, have a preventive effect on the risk of death. The aim of this study was to compare the risk of death among patients with colorectal cancer with diabetes with different levels of adherence to oral antidiabetics.

METHODS

National Health Information Database was used, which has all claims data for those who are registered for national health insurance in Korea, from 2002 to 2016, for conducting a retrospective cohort study. Newly diagnosed patients with colorectal cancer among diabetics were followed up from the date of diagnosis until death or December 31, 2016. The medication adherence was calculated as the proportion of days covered (PDC). The HR and 95% confidence interval (CI) for death were estimated using the low-adherence patients as a reference.

RESULTS

A total of 33,841 diabetic patients with newly diagnosed colorectal cancer were followed for an average of 4.7 years. Patients with colorectal cancer with good adherence (PDC ≥ 80%) showed a reduced risk of death [HR (95% CI), 0.82 (0.78-0.86)] compared with those with poor adherence (PDC < 80%). A reduced risk of death was observed for all cancer subsites.

CONCLUSIONS

The maintenance of good medication adherence for diabetes mellitus was related to a favorable prognosis of colorectal cancer.

IMPACT

This study provides evidence that patients with colorectal cancer who are adherent to their diabetes medication will have better survival than patients who are not adherent.

The effect of metformin on gastric cancer in patients with type 2 diabetes: a systematic review and meta-analysis

BACKGROUND

Metformin, a drug widely used in the treatment of diabetes, has proven preventive and survival benefits for various malignancies. However, the effect of metformin on gastric cancer risk and survival rate in T2DM patients remains controversial. Therefore, we conducted a systematic review and meta-analysis to evaluate the effect of metformin on gastric cancer in T2DM patients.

METHODS

We searched PubMed, EMBASE, Medline and the Cochrane Library for related studies up to October 22, 2019. Pooled hazard ratios with 95% confidence intervals were calculated using random-effects model. Heterogeneity was assessed. All articles were evaluated by Newcastle-Ottawa Scale.

RESULTS

A total of 11 cohort studies met eligibility criteria and were included in the meta-analysis. The use of metformin was related to a significant 21% reduction in GC incidence (HR 0.790; 95% CI 0.624-1.001). Subgroup analysis showed that the use of metformin significantly reduced the risk of gastric cancer in T2DM patients in Asian populations, but not in western populations. In a pooled analysis of 3 studies, metformin use was associated with increased overall survival rate (HR 0.817; 95% CI 0.600-1.113) and cancer-specific survival rate (HR 0.824; 95% CI 0.614-1.106) of T2DM patients.

CONCLUSIONS

Metformin could reduce the risk of gastric cancer in T2DM patients, particularly in Asian populations. However, it is debatable whether metformin use can improve the prognosis of gastric cancer in T2DM patients.

The right place for metformin today

Metformin is the most widely used glucose lowering drug worldwide in the treatment of patients with type 2 diabetes, since we have experience with this drug for more than 60 years about the efficacy and safety. Metformin is very effective in HbA1c lowering associated with some weight loss, but does not increase risk for hypoglycemia. At the moment all guidelines in the world recommend to use metformin in monotherapy in patients with newly diagnosed diabetes or in combination with other antidiabetic drugs with documented CV (and renal) benefit in cardiovascular outcome trials (CVOT). Although a randomized placebo controlled CVOT with metformin is lacking, many observational studies in patients with coronary heart disease, heart failure and chronic kidney disease have demonstrated consistent beneficial effects. A recent metanalysis of 26 observational studies including 815 839 patients showed that metformin use was associated with a significantly lower rate of all-cause mortality (HR: 0.74; 95% CI: 0.68-0.81). Whether this very consistent reduction of all-cause mortality is related to the incidence/outcome of several cancers has still to be investigated. In the future early combination therapy of metformin e.g. with SGLT-2 inhibitors should be more often used.

Effects of propofol and sevoflurane on blood glucose, hemodynamics, and inflammatory factors of patients with type 2 diabetes mellitus and gastric cancer

Effects of propofol and sevoflurane on blood glucose, hemodynamics, and inflammatory factors of patients with type 2 diabetes mellitus (T2DM) and gastric cancer (GC) were investigated. One hundred and ten patients with T2DM and GC, treated in The First Affiliated Hospital of Baotou Medical College (Baotou, China) from January 2017 to December 2018, were selected. Sixty patients anesthetized by propofol were included in the propofol group, whereas 50 patients anesthetized by sevoflurane were included in the sevoflurane group. The level of blood glucose, hemodynamic indicators, and inflammatory factors of the patients in the two groups were compared at T₀ (before anesthesia), T₁ (2 min after intubation), T₂ (5 min after pneumoperitoneum), and T₃ (60 min after surgery). Mini-Mental State Examination (MMSE) cognitive function scores were compared at T0 (before anesthesia), T4 (6 h after surgery), and T5 (72 h after surgery) between the two groups. The anesthetic effect and the incidence of adverse reactions were also compared between the two groups. The heart rate (HR), oxygen saturation (SpO₂) and average artery pressure decreased slightly and then increased after the surgery was started; whereas, the levels of the serum inflammatory factors first increased and then decreased, to return to their initial levels. MMSE scores of the patients in two groups at T₄ were significantly lower than those at T₀ (P<0.05), and the MMSE score at T₄ was significantly higher in the propofol group than that in the sevoflurane group (P<0.05). The time of spontaneous breathing, verbal response, eye opening, and extubation in the propofol group was significantly shorter than that in the sevoflurane group (P<0.05). The incidence of adverse reactions in the propofol group was lower than that in the sevoflurane group. The effect of propofol is less than that of sevoflurane, thus propofol is more suitable for the anesthesia of patients with T2DM and GC.

Suppressive effects of metformin on colorectal adenoma incidence and malignant progression

BACKGROUND

The linear progression from normal colonic epithelium to adenoma initiation, carcinoma transformation and metastasis is considered the classical model of colorectal cancer (CRC) development. Although metformin has been extensively reported to be negatively related to cancer incidence, the effect of metformin on CRC development remains unclear. We aimed to evaluate the role of metformin in the entire CRC linear progression.

METHODS

Systematic searches and data extraction were performed in the PubMed, Embase, and Cochrane Library databases on Jan 31, 2019. The combined relative ratios (RRs) of colorectal tumor incidence and the hazard ratios (HRs) of overall survival (OS) and cancer-specific survival (CSS) were evaluated by a random-effects model. Then, the effects of metformin were further assessed through stratified analyses by population, medication duration and dosage, dose-response analysis and comparison with other antidiabetic agents.

RESULTS

A total of 50 studies consisting of 238,540 cases of diabetes mellitus (DM) were included in this study. Metformin use was negatively associated with the incidence of colorectal adenoma (RR: 0.75, 95% CI: 0.65-0.86) and CRC (RR: 0.73, 95% CI: 0.58-0.90). Moreover, CRC patients benefited from metformin in terms of both OS (HR: 0.73, 95% Cl: 0.63-0.84) and CSS (HR: 0.60, 95% Cl: 0.50-0.73). Stratified analyses suggested that a long duration of high-dose metformin (RR: 0.52, 95% Cl: 0.36-0.83) was more effective than a short duration in Asian populations against colorectal adenoma (RR: 0.66, 95% Cl: 056-0.70) and CRC (RR: 0.45, 95% Cl: 0.29-0.70). Interestingly, metformin use decreased CRC risk in a dose-dependent manner (RR: 0.91, 95% CI: 0.87-0.95). In addition, the benefit of metformin on CRC was more significant than that of other antidiabetic agents, including insulin.

CONCLUSIONS

The use of metformin is associated with a lower incidence of adenoma and CRC and a better prognosis, especially in Asian populations.

A cohort study of antihyperglycemic medication exposure and survival in patients with gastric cancer

Objective: We aimed to estimate survival in gastric cancer patients with type 2 diabetes mellitus (T2DM) using different antihyperglycemic medication.

Methods: Patients with gastric cancer and diabetes between 2003-2013 were identified form The Lithuanian Cancer Registry and The National Health Insurance Fund database. Cohort members were classified into five groups: four groups of T2DM patients according to treatment: metformin users; metformin and other medication users; sulphonylurea users; insulin and other medication users; and non-diabetic group. Kaplan-Meier survival analysis and Cox proportional hazards models were used to estimate gastric cancer-specific survival and overall survival.

Results: 8423 patients met eligibility criteria. Survival analysis showed no differences in gastric cancer-specific survival between non-diabetic and diabetic patient groups. Better survival was observed in the groups of patients using antihyperglycemic medication combinations with metformin, metformin alone or insulin. Lowest survival was observed in diabetic patients who were sulphonylurea users. Survival analysis comparing overall survival between non-diabetic and diabetic patients (p = 0.89) showed no evidence of survival difference between groups and survival differences between antihyperglycemic medication user groups were of borderline significance (p = 0.052).

Conclusions: Antihyperglycemic medication use was not associated with a significant effect on survival in patients with gastric cancer and T2DM.

Use of Antihypertensive Medications and Survival Rates for Breast, Colorectal, Lung, or Stomach Cancer

Using time-dependent Cox regression models, we examined associations of common antihypertensive medications with overall cancer survival (OS) and disease-specific survival (DSS), with comprehensive adjustment for potential confounding factors. Participants were from the Shanghai Women's Health Study (1996-2000) and Shanghai Men's Health Study (2002-2006) in Shanghai, China. Included were 2,891 incident breast, colorectal, lung, and stomach cancer cases. Medication use was extracted from electronic medical records. With a median 3.4-year follow-up after diagnosis (interquartile range, 1.0-6.3), we found better outcomes among users of angiotensin II receptor blockers with colorectal cancer (OS: adjusted hazard ratio (HR) = 0.62, 95% confidence interval (CI): 0.44, 0.86; DSS: adjusted HR = 0.61, 95% CI: 0.43, 0.87) and stomach cancer (OS: adjusted HR = 0.62, 95% CI: 0.41, 0.94; DSS: adjusted HR = 0.63, 95% CI: 0.41, 0.98) and among users of β-adrenergic receptor blockers with colorectal cancer (OS: adjusted HR = 0.50, 95% CI: 0.35, 0.72; DSS: adjusted HR = 0.50, 95% CI: 0.34, 0.73). Better survival was also found for calcium channel blockers (DSS: adjusted HR = 0.67, 95% CI: 0.47, 0.97) and diuretics (OS: adjusted HR = 0.66, 95% CI: 0.45, 0.96; DSS: adjusted HR = 0.57, 95% CI: 0.38, 0.85) with stomach cancer. Our findings suggest angiotensin II receptor blockers, β-adrenergic receptor blockers, and calcium channel blockers might be associated with improved survival outcomes of gastrointestinal cancers.

A more physiological approach to lipid metabolism alterations in cancer: CRC-like organoids assessment

Precision medicine might be the response to the recent questioning of the use of metformin as an anticancer drug in colorectal cancer (CRC). Thus, in order to establish properly its benefits, metformin application needs to be assayed on the different progression stages of CRC. In this way, intestinal organoids imply a more physiological tool, representing a new therapeutic opportunity for CRC personalized treatment to assay tumor stage-dependent drugs. The previously reported lipid metabolism-related axis, Acyl-CoA synthetases/ Stearoyl-CoA desaturase (ACSLs/SCD), stimulates colon cancer progression and metformin is able to rescue the invasive and migratory phenotype conferred to cancer cells upon this axis overexpression. Therefore, we checked ACSL/SCD axis status, its regulatory miRNAs and the effect of metformin treatment in intestinal organoids with the most common acquired mutations in a sporadic CRC (CRC-like organoids) as a model for specific and personalized treatment. Despite ACSL4 expression is upregulated progressively in CRC-like organoids, metformin is able to downregulate its expression, especially in the first two stages (I, II). Besides, organoids are clearly more sensitive in the first stage (Apc mutated) to metformin than current chemotherapeutic drugs such as fluorouracil (5-FU). Metformin performs an independent "Warburg effect" blockade to cancer progression and is able to reduce crypt stem cell markers expression such as LGR5+. These results suggest a putative increased efficiency of the use of metformin in early stages of CRC than in advanced disease.

Diabetes Mellitus and Colon Carcinogenesis: Expectation for Inhibition of Colon Carcinogenesis by Oral Hypoglycemic Drugs

The global deaths due to colorectal cancer and diabetes mellitus have increased by 57% and 90%, respectively. The relationship between various cancers and diabetes mellitus has been shown in multiple epidemiological studies. Hence, better management of diabetes mellitus is expected to reduce the risk of various cancers. This review focuses on colorectal cancer and aims to summarize recent findings on the antitumor effects of various oral hypoglycemic drugs on colorectal cancer and their estimated mechanisms. Of the seven classes of oral hypoglycemic agents, only metformin was found to have suppressive effects on colorectal cancer in both clinical and basic research. Clinical and basic researches on suppressing effects of glinides, dipeptidyl peptidase-4 inhibitors, thiazolidinedione, α-glucosidase inhibitors, and sodium glucose cotransporter-2 inhibitors against colon carcinogenesis have been insufficient and have not arrived at any conclusion. Therefore, further research regarding these agents is warranted. In addition, the suppressive effects of these agents in healthy subjects without diabetes should also be investigated.