Metformin use and survival after non-small cell lung cancer: A cohort study in the US Military health system

MilCanEpi: Increased Capability for Cancer Care Research in the Department of Defense

The Military Health System (MHS) of the US Department of Defense (DoD) provides comprehensive medical care to over nine million beneficiaries, including active-duty members, reservists, activated National Guard, military retirees, and their family members. The MHS generates an extensive database containing administrative claims and medical encounter data, while the DoD also maintains a cancer registry that collects information about the occurrence of cancer among its beneficiaries who receive care at military treatment facilities. Collating data from the two sources diminishes the limitations of using registry or medical claims data alone for cancer research and extends their usage. To facilitate cancer research using the unique military health resources, a computer interface linking the two databases has been developed, called Military Cancer Epidemiology, or MilCanEpi. The intent of this article is to provide an overview of the MilCanEpi data system, describing its components, structure, potential uses, and limitations.

Metformin and cancer hallmarks: shedding new lights on therapeutic repurposing

Metformin is a well-known anti-diabetic drug that has been repurposed for several emerging applications, including as an anti-cancer agent. It boasts the distinct advantages of an excellent safety and tolerability profile and high cost-effectiveness at less than one US dollar per daily dose. Epidemiological evidence reveals that metformin reduces the risk of cancer and decreases cancer-related mortality in patients with diabetes; however, the exact mechanisms are not well understood. Energy metabolism may be central to the mechanism of action. Based on altering whole-body energy metabolism or cellular state, metformin's modes of action can be divided into two broad, non-mutually exclusive categories: "direct effects", which induce a direct effect on cancer cells, independent of blood glucose and insulin levels, and "indirect effects" that arise from systemic metabolic changes depending on blood glucose and insulin levels. In this review, we summarize an updated account of the current knowledge on metformin antitumor action, elaborate on the underlying mechanisms in terms of the hallmarks of cancer, and propose potential applications for repurposing metformin for cancer therapeutics.

Efficacy of metformin adjunctive therapy as the treatment for non-diabetic patients with advanced non-small cell lung cancer: A Systematic review and Meta-analysis

Background

Currently, the anticancer effects of metformin on different types of lung cancer have been frequently studied. However, the relationship between metformin and prognosis in nondiabetic patients with lung cancer remains controversial. To systematically evaluate the efficacy of metformin adjunctive therapy as the treatment for nondiabetic patients with advanced non-small cell lung cancer (NSCLC) to provide an evidence-based reference for clinical medication.

Materials and Methods

The literatures related to Phase II or III randomized controlled trials (RCTs) of metformin adjunctive therapy in nondiabetic patients with advanced NSCLC, including EMBASE, PubMed, the Cochrane Library, and Scopus database, were retrieved by computer, and the search time ranged from January 2017 to August 2022. The risk of bias assessment tool recommended by Cochrane Systematic Evaluator Manual 5.1.0 was used to evaluate the quality of the RCTs included. Rev Man 5.3 software and STATA15.0 were used for meta-analysis.

Results

A total of 8 studies were included (925 patients). Meta-analysis results showed that there were no significant differences in progression-free survival (PFS) (hazard ratio [HR] = 0.95, 95% confidence interval [CI]: 0.66-1.36, P = 0.77), overall survival (OS) (HR = 0.89, 95% CI: 0.61-1.30, P = 0.55, n =7), objective response rate (ORR) (odds ratio [OR] = 1.37, 95% CI: 0.76-2.46, P = 0.30), and 1-year PFS rate (OR = 0.87, 95% CI: 0.39-1.94, P = 0.73, n = 3). Sensitivity analysis showed that PFS and OS indexes were stable.

Conclusion

Metformin adjunctive therapy can improve the DCR of nondiabetic patients with advanced NSCLC. In addition, the patients cannot obtain a prolonged PFS, OS, 1-year PFS rate, and higher ORR rate.

Prognostic value of metformin in cancers: An updated meta-analysis based on 80 cohort studies

BACKGROUND

Experiments have shown that metformin can inhibit cancer cell growth, but clinical observations have been inconsistent, so we pooled the currently available data to evaluate the impact of metformin on cancer survival and progression.

METHODS

PubMed, web of science, Embase, and Cochrane databases were searched. Pooled hazard ratios (HRs) were identified using a random-effects model to estimate the strength of the association between metformin and survival and progression in cancer patients.

RESULTS

We incorporated 80 articles published from all databases which satisfied the inclusion criterion. It showed that metformin was associated with better overall survival (hazard ratio [HR] = 0. 81; 95% confidence interval [CI]: [0.77-0.85]) and cancer-specific survival (HR = 0.79; 95% CI: [0.73-0.86]), and metformin was associated with progression-free survival (HR = 0.76; 95% CI: [0.66-0.87]). In patients with diabetes mellitus, the HR of overall survival was 0.79(95% CI: [0.75-0.83]), progression-free survival was 0.72(95% CI: [0.60-0.85]), and the cancer-specific survival was 0.76(95% CI: [0.68-0.86]). It was proposed that metformin can improve the prognosis of cancer patients with diabetes mellitus.

CONCLUSION

Based on cohort studies, metformin therapy has potential survival benefits for patients with malignancy, especially with the greatest benefits seen in breast cancer on overall survival, progression-free survival, and cancer-specific survival. And metformin also showed potential benefits in cancer-specific survival in colorectal and prostate cancer.

An injectable vitreous substitute with sustained release of metformin for enhanced uveal melanoma immunotherapy

Uveal melanoma (UM) is the most prevalent primary intraocular malignant tumor in adults with a high rate of metastasis. Conventional treatments have limited effects on metastasis and cause permanent ocular tissue defects. Here, a novel strategy based on an injectable vitreous substitute with sustained metformin release ability (IVS-Met) was reported for efficient UM therapy as well as for repairing vitreous deficiency and preserving visual function. IVS-Met showed an excellent long-term anti-tumor effect by direct tumor attack and modulation of the tumor microenvironment (TME). IVS-Met reduced the proportion of pro-tumor M2 tumor-associated macrophages and induced the pro-inflammatory M1 phenotype, thus reversing the immunosuppressive TME and eliciting robust anti-tumor immune responses. Notably, IVS-Met demonstrated high performance in the inhibition of UM metastasis and significantly extended the survival time of mice. In addition, the vitreous substitute achieved facile administration via direct injection and exhibited excellent rheological and optical properties with the key parameters very close to those of the vitreous body to repair vitreous deficiency and preserve visual function. In summary, this strategy has realized effective UM treatment while retaining eyeballs and vision for the first time, revealing great potential for translation to clinical practice.

Triglyceride glucose index and Atherogenic index of plasma for predicting colorectal neoplasms in patients without cardiovascular diseases

BACKGROUND AND AIMS

Colorectal neoplasms (CRN) include colorectal cancer (CRC) and colorectal adenoma (CRA). The relationship between CRN and triglyceride-glucose (TyG) index or between CRN and atherogenic index of plasma (AIP) is unclear. This study aims to investigate the roles of TyG index and AIP in predicting CRN in people without cardiovascular disease (CVD).

METHODS

2409 patients without CVD underwent colonoscopy were enrolled. Clinical information and relevant laboratory test results of these patients were collected and recorded. According to endoscopic and pathological results, all participants were divided into a neoplasms group and a non-neoplasms group. The TyG index was calculated as ln (TGs×FPG/2), while AIP was calculated as log (TGs/HDL-C). We used uni- and multivariate logistic regression and restricted cubic spline (RCS) to analyze the association between the TyG inedx, AIP and CRN, develop predictive models and construct the nomograms. Receiver operating characteristic (ROC) curves were utilized to evaluate the predictive value for CRN.

RESULTS

Participants in the neoplasms group were more likely to be older, have higher TyG index, higher AIP and higher rates of fecal occult blood test positivity, and were more likely to be male, smokers and those with the family history of CRC (P < 0.05). The higher TyG index was related to the higher risk of CRN [OR (95% CI): 1.23 (1.08 - 1.41), P = 0.003]. The higher AIP was related to the higher risk of CRN [OR (95% CI): 1.55 (1.16 - 2.06), P = 0.003]. These two indicators are better for predicting CRN in women than men. The combined use of the TyG index and other independent risk factors (age, sex, smoking status, family history and FOBT) to distinguish CRN was effective, with a sensitivity of 61.0%, a specificity of 65.1% and an AUC of 0.669 (95%CI, 0.639 - 0.698). Likewise, the combined use of the AIP and other independent risk factors to distinguish CRN was also effective, the model had an overall 56.3% sensitivity and 68.7% specificity with an AUC of 0.667 (95%CI, 0.638 - 0.697).

CONCLUSION

This study showed that the TyG index and the AIP might be biomarkers that could be used to predict the risk of CRN in patients without CVD.

The role of metformin on lung cancer survival: the first systematic review and meta-analysis of observational studies and randomized clinical trials

PURPOSE

To assess the effects of metformin use on lung cancer (LC) survival according to summarized results from observational studies (OBs) and randomized clinical trials (RCTs).

METHODS

We systematically searched electronic databases and, to our knowledge, for the first time, RCTs were included in a systematic review and meta-analysis about the role of metformin on LC survival. We carried out meta-analyses separately for OBs and RCTs. Analyses for overall survival (OS) concerning OBs were stratified by studies with and without time-dependent approach. Subgroup analyses were adopted for OBs to identify the sources of heterogeneity. Included studies were assessed for quality.

RESULTS

We identified ten OBs and four RCTs. For OBs, metformin use was associated with improved OS for LC patients. Only two studies used time-dependent approach in which a higher ratio was found when compared to the non-use of the time-dependent analysis in eight studies. OBs were classified as high quality but the risk of bias was "unclear" in eight OBs due to absence of the time-dependent analysis. For RCTs, metformin use was not beneficial for OS and neither for progression-free survival. Heterogeneous quality was found among RCTs. Sources of bias that could alter significantly the results or raise doubts were identified in RCTs.

CONCLUSION

Time-dependent analysis should be considered an appropriate strategy for OBs focused on the metformin use for LC patients' survival, and further studies applying this approach are required. More well-designed RCTs are needed to provide consistent results for the association between metformin use and LC survival.

Targeting the PI3K/AKT/mTOR Signaling Pathway in Lung Cancer: An Update Regarding Potential Drugs and Natural Products

Lung cancer is one of the most common cancers and has a high mortality rate. Due to its high incidence, the clinical management of the disease remains a major challenge. Several reports have documented a relationship between the phosphatidylinositol-3-kinase (PI3K)/ protein kinase B (AKT)/ mammalian target of rapamycin (mTOR) pathway and lung cancer. The recognition of this pathway as a notable therapeutic target in lung cancer is mainly due to its central involvement in the initiation and progression of the disease. Interest in using natural and synthetic medications to target these signaling pathways has increased in recent years, with promising results in vitro, in vivo, and in clinical trials. In this review, we focus on the current understanding of PI3K/AKT/mTOR signaling in tumor development. In addition to the signaling pathway, we highlighted the therapeutic potential of recently developed PI3K/AKT/mTOR inhibitors based on preclinical and clinical trials.

Concurrent use of metformin enhances the efficacy of EGFR-TKIs in patients with advanced EGFR-mutant non-small cell lung cancer-an option for overcoming EGFR-TKI resistance

Background

Resistance is almost inevitable and is still a major obstacle in epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) therapy. Only limited relevant clinical studies evaluated the therapeutic effects by combing metformin and EGFR-TKIs in non-small cell lung cancer (NSCLC) patients. Therefore, we evaluated the efficacy of concurrent use of metformin with EGFR-TKIs, and assessed whether the addition of metformin may improve clinical outcomes and delay the occurrence of EGFR-TKI resistance.

Methods

We conducted cell proliferation and apoptosis assay for investigation of metformin in combination with EGFR-TKIs to overcome EGFR-TKI resistance in vitro. Furthermore, we retrospectively reviewed clinicopathological characteristics and therapeutic outcomes of EGFR-mutant advanced NSCLC diabetic patients who received EGFR-TKIs with or without concurrent use of metformin.

Results

In vitro experiment, metformin showed synergistic interaction both with gefitinib in PC9R (CI =0.77) and with osimertinib in PC9R/OR (CI =0.77) in proliferation inhibition assay. Metformin can also augment apoptosis effect of these TKI-resistant cells to EGFR-TKIs. In retrospective cohort, a total of 85 patients were identified (cohort A), in which 28 patients had concurrent use of metformin. The objective response rate in metformin use group was significantly higher (85.7% vs. 47.4%, P=0.001). The median progression-free survival (PFS) and overall survival (OS) in metformin use group were significantly longer (21.6 vs. 9.2 months, P=0.000; 48.4 vs. 36.6 months, P=0.049). Further analysis revealed that metformin obviously prolonged the median PFS2 of osimertinib treatment among patients who progressed to prior line EGFR-TKIs due to secondary EGFR T790M mutation (cohort B).

Conclusions

Our study suggest that concurrent use of metformin could be beneficial to EGFR-mutant NSCLC patients treated with either first-line EGFR-TKIs or second-line osimertinib.

Metformin use and lung cancer survival: a population-based study in Norway

BACKGROUND

We assessed associations between metformin use and survival in a nationwide Norwegian cohort of lung cancer (LC) patients.

METHODS

The study linked 22,324 LC patients from the Cancer Registry of Norway diagnosed 2005-2014 with the Norwegian Prescription Database. We estimated associations of pre- and post-diagnostic metformin use with overall survival (OS) and LC-specific survival (LCSS) using multivariable time-fixed and time-dependent Cox regression.

RESULTS

Pre-diagnostic metformin use was not associated with improved survival in all patients. Nevertheless, pre-diagnostic metformin use was associated with better LCSS in squamous cell carcinoma (SCC) patients (hazard ratio (HR) = 0.79; 95% confidence interval (CI) 0.62-0.99) and in patients with regional stage SCC (HR = 0.67; 95%CI 0.47-0.95). Post-diagnostic metformin use was associated with improved LCSS in all patients (HR = 0.83; 95%CI 0.73-0.95), in patients with SCC (HR = 0.75; 95%CI 0.57-0.98), regional stage LC (HR = 0.74; 95%CI 0.59-0.94), and regional stage SCC (HR = 0.57; 95%CI 0.38-0.86). OS showed similar results. Analyses of cumulative use showed a dose-response relationship in all patients, patients with adenocarcinoma and SCC, and with regional and metastatic LC.

CONCLUSIONS

Metformin use was associated with improved survival, especially LCSS in patients with regional stage SCC. Further prospective studies are required to clarify the role of metformin in LC treatment.

Prolonged progression-free survival and overall survival are associated with diabetes mellitus but inversely associated with levels of blood glucose in patients with lung cancer

BACKGROUND

Previous studies have provided conflicting evidence about the increased overall survival (OS) in lung cancer patients with diabetes mellitus (DM) compared with those without DM. This study assessed progression-free survival (PFS)/OS in lung cancer patients with or without DM and tentatively analyzed the impact of blood glucose levels on PFS/OS in lung cancer patients.

METHODS

Data were collected from lung cancer patients based upon admission records from January 2010 to January 2012 and follow-up records from January 2010 to January 2015 in the Department of Pulmonary Medicine, Zhongshan Hospital, Fudan University, Shanghai. The data included patient sex, age, body mass index (BMI), smoking status, history of DM, level of blood glucose, pathological type, clinical stage of cancer, chemotherapy regimen, and history of anti-DM drugs. The Cox regression model and Kaplan-Meier method were used for the analysis of hazard factors and PFS/OS. For comparison of PFS/OS in lung cancer with or without DM, patients were divided into three groups: lung cancer with DM, lung cancer without DM but with elevated level of blood glucose, lung cancer without DM or elevated level of blood glucose.

RESULTS

In total, the data from 200 lung cancer patients (138 males/62 females, aged 29.0 to 78.0 years, mean 60.0 ± 8.6 years) were collected. For the comparison of PFS/OS in lung cancer patients with or without DM, patients were divided into three groups: lung cancer with DM (n = 31); lung cancer without DM but with elevated levels of blood glucose (n = 40); and lung cancer without both DM and elevated levels of blood glucose (n = 128), whereas 1 patient dropped out of the study. All the patients underwent complete chemotherapy and were followed up for 36.0 to 60.0 months. Kaplan-Meier survival analysis showed that lung cancer patients with DM had increased PFS and OS compared with those without DM (log-rank, P < 0.05, P < 0.01); the median PFS in lung cancer with DM was 12.0 months (95% confidence interval [CI], 4.0-16.0) vs. 6.0 months in those without DM (95% CI, 5.8-6.3); and the median OS in lung cancer patients with DM was 37.0 months (95% CI, 29.0-46.6) vs. 12.0 months in those without DM (95% CI, 10.9-13.1). For the other two groups of patients without DM, there was a trend toward a shorter PFS and OS in patients with elevated blood glucose compared with those without elevated blood glucose. Cox regression showed that PFS in lung cancer patients was favorably associated with the usage of anti-DM drugs, BMI, clinical stage of cancer, and chemotherapy regimen (all P < 0.05) but was inversely associated with the level of blood glucose (P < 0.05).

CONCLUSIONS

Lung cancer patients with DM have prolonged PFS and OS compared with those without DM, and the level of blood glucose was inversely associated with PFS. The current results indicate that PFS may be a meaningful intermediate endpoint for OS and that the levels of blood glucose hopefully represent a prognostic factor in lung cancer patients.

The potential adjunctive benefit of adding metformin to standard treatment in inoperable cancer patients: a meta-analysis of randomized controlled trials

Background

Recently, there have been several randomized clinical trials (RCTs) conducted to evaluate the efficacy and safety of metformin plus standard treatment in inoperable cancer patients. Our meta-analysis aimed to assess the efficacy of metformin in combination with standard treatment in inoperable cancer patients.

Methods

PubMed and Embase databases were systematically searched for relevant RCTs investigating the efficacy of adding metformin to standard treatment for cancer patients. The pooled relative risk (RR) for tumor response and safety was calculated to assess the efficacy of combining metformin with standard treatment. Meta-analysis was subsequently performed to pool the hazard ratio (HR) for overall survival (OS) and progression-free survival (PFS).

Results

Ten RCTs comprising 1033 patients were included in our current meta-analysis. In patients with breast cancer, results of meta-analysis showed that the addition of metformin to standard treatment was beneficial to objective response rate (ORR) with 30.3% (33/109) in the metformin plus standard treatment group and 16.1% (18/112) in the placebo group (RR 1.92, 95% CI: 1.19–3.10, P=0.008). OS and PFS were not significantly improved in patients who received metformin plus standard treatment compared with those who received placebo plus standard treatment (OS: HR 1.02, 95% CI: 0.71–1.46, P=0.916; PFS: HR 1.14, 95% CI: 0.86–1.50, P=0.366). For lung cancer patients, meta-analysis results showed adding metformin to standard treatment could benefit ORR (metformin 65.3% vs. placebo 54.6%, RR 1.22, 95% CI: 1.03–1.43, P=0.018) with no significant survival benefit in the metformin group. For patients with pancreatic cancer, the pooled ORR was 17.6% (16/91) in metformin plus standard treatment group and 20% (18/90) in the placebo group, indicating metformin did not benefit ORR (RR 0.85, 95% CI: 0.49–1.49, P=0.576). Besides, the addition of metformin to standard treatment did not increase the incidence rate of adverse effects.

Conclusions

Our results indicated that addition of metformin to standard treatment was beneficial to ORR in inoperable breast or lung cancer patients without increasing the incidence of adverse effects. However, adding metformin to standard treatment could not benefit OS and PFS.

Time course and dose effect of metformin on weight in patients with different disease states

OBJECTIVES

The present study was to quantitate and compare the efficacy of metformin on weight in different disease states using model-based meta-analysis (MBMA).

METHODS

Randomized controlled trials (RCT) of metformin effects on weight in different disease states were collected by searching the public databases. The change rate of weight from baseline was selected as the efficacy indicator.

RESULTS

A total 21 RCTs containing 1885 patients including patients with type 2 diabetes mellitus, patients with antipsychotic induced weight gain, patients with obesity, were included into the present study. After deducting placebo effect, the maximal effect (E_max) of metformin on weight in patients with type 2 diabetes mellitus, patients with antipsychotic induced weight gain, patients with obesity were -6.86%, -8.82%, and -4.14%, respectively. The treatment duration to reach half of the maximal effect (ET₅₀) were 107, 45.5, and 15.1 weeks, respectively. Within the metformin dose range from 21 RCTs, no significant dose-response relationship was observed. However, the time-course relationship is obvious for efficacy of metformin on weight.

CONCLUSIONS

The present study firstly provided quantitative information for metformin effects on weight in different disease states, including patients with type 2 diabetes mellitus, patients with antipsychotic induced weight gain, patients with obesity.

Clinicopathological and prognostic features of operable non-small cell lung cancer patients with diabetes mellitus

BACKGROUND

The aim of this study was to investigate the clinicopathological and prognostic features of operable non-small cell lung cancer (NSCLC) patients with diabetes mellitus (DM).

METHODS

A total of 1231 surgically resected NSCLC patients were retrospectively reviewed. Clinicopathological characteristics were compared between patients with DM (DM group, n = 139) and those without DM (non-DM group, n = 1092). The clinical factors associated with postoperative complications and prognostic factors were identified.

RESULTS

The DM group had distinct clinicopathological features. No significant differences in histological invasiveness or stage were found. The presence and control status of DM were independent predictors of postoperative complications. No significant differences in recurrence-free survival or cancer-specific survival were observed; however, the DM group had worse overall survival (OS). The DM group had a higher number of deaths from other diseases than the non-DM group, and these patients had significantly higher postoperative hemoglobin A1c levels than patients with cancer-related death.

CONCLUSION

The presence and control status of preoperative DM are useful predictors of both postoperative complications and OS in operable NSCLC patients. Concomitant diabetes-related complications have a negative effect on long-term survival in diabetic NSCLC patients, and long-term glycemic control is important to prolong OS.

The Associations of Aspirin, Statins, and Metformin With Lung Cancer Risk and Related Mortality: A Time-Dependent Analysis of Population-Based Nationally Representative Data

INTRODUCTION

The aim of this study was to investigate the associations of aspirin, metformin, and statins with lung cancer risk and mortality using population-based nationwide cohort data.

METHODS

This study included a total of 732,199 participants who underwent a national health check-up from 2002 to 2003. Lung cancer incidence and mortality were identified using a registered lung cancer diagnosis code (International Classification of Diseases, 10th revision, code C34) and the Korean National Death Registry. The study participants were followed up from January 1, 2004 to December 31, 2013. Medication exposure was defined by the cumulative duration of use and cumulative defined daily dose per 2-year interval. To avoid immortal-time bias, drug exposure was inserted as a time-dependent variable in Cox analysis, which evaluated the associations of these medications with lung cancer.

RESULTS

Metformin use had a protective association with lung cancer incidence (p's for trend 0.008) and mortality (p's for trend < 0.001) in a dose-response fashion, and these associations were prominent among participants with a metformin cumulative defined daily dose of 547.5 and above compared with patients without diabetes. Lung cancer mortality was dose-dependently reduced with the use of aspirin (p's for trends 0.046) and statin (p's for trends < 0.001). The combined use of aspirin, statins, and metformin exhibited more prominent protective associations with lung cancer risk and mortality.

CONCLUSIONS

The use of aspirin, metformin, and statins had independent protective associations with lung cancer mortality, and metformin had an inverse association with lung cancer risk. Further studies are necessary to develop clinically applicable anticancer strategies using these drugs for the reduction of lung cancer and related mortality.

The genetic association between type 2 diabetic and hepatocellular carcinomas

Background

Type 2 diabetes mellitus (T2DM) and hepatocellular carcinoma (HCC) are both major health problems throughout the world. It has been reported that T2DM is an independent risk factor for HCC, although the pathophysiology is still unclear.

Methods

In order to identify differentially expressed genes (DEGs) in T2DM and HCC, gene expression datasets for T2DM (GSE15653), HCC (GSE60502) and metformin-treated cells (GSE69850) were obtained from the Gene Expression Omnibus database repository. Protein-protein interaction (PPI) networks for the DEGs were constructed and gene clusters selected for functional enrichment analysis. Ten genes with the highest degree of connectivity were selected as hub genes and prognostic analysis together with analysis of gene expression and protein distribution were performed for these genes. Lastly, we investigated associations between the hub genes and genes associated with metformin treatment in hepatocarcinoma cells.

Results

In total, 256 common DEGs, including 155 up-regulated genes and 101 down-regulated genes, were identified. Enrichment analyses showed that the genes of the major module were largely associated with the cell cycle. All of the 10 hub genes (CCNA2, CCNB1, MAD2L1, BU1B, RACGAP1, CHEK1, BUB1, ASPM, NCAPG and TTK) have a strong association with lower overall survival in liver cancer patients and four genes (CCNA2, CCNB1, CHEK1 and BUB1) have reduced expression in metformin-treated samples.

Conclusions

This study identified a number of genes that may play important roles in the association of T2DM and HCC, including four genes which may be the target of metformin treatment for diabetes and HCC. The specific mechanisms involved remain to be identified.

Combination of Metformin and Gefitinib as First-Line Therapy for Nondiabetic Advanced NSCLC Patients with EGFR Mutations: A Randomized, Double-Blind Phase II Trial

PURPOSE

Preclinical and retrospective studies suggested a role for metformin in sensitizing patients who have diabetes with non-small cell lung cancer (NSCLC) to EGFR tyrosine kinase inhibitors (TKIs). We therefore examined its effects in combination with gefitinib in patients without diabetes harboring EGFR mutations (EGFRm).

PATIENTS AND METHODS

A total of 224 patients without diabetes with treatment-naïve stage IIIB-IV EGFRm NSCLC were randomly assigned in a 1:1 ratio to receive gefitinib plus either metformin or placebo. The primary endpoint was progression-free survival (PFS) rate at 1 year and secondary endpoints included overall survival (OS), PFS, objective response rate (ORR), and safety. Serum levels of IL6 were also examined in an exploratory analysis.

RESULTS

The median duration of follow-up was 19.15 months. The estimated 1-year PFS rates were 41.2% [95% confidence interval (CI), 30.0-52.2] with gefitinib plus metformin and 42.9% (95% CI, 32.6-52.7) with gefitinib plus placebo (P = 0.6268). Median PFS (10.3 months vs. 11.4 months) and median OS (22.0 months vs. 27.5 months) were numerically lower in the metformin group, while ORRs were similar between the two arms (66% vs. 66.7%). No significant treatment group differences were detected across all subgroups with respect to PFS, including those with elevated levels of IL6. Metformin combined with gefitinib resulted in a remarkably higher incidence of diarrhea compared with the control arm (78.38% vs. 43.24%).

CONCLUSIONS

Our study showed that addition of metformin resulted in nonsignificantly worse outcomes and increased toxicity and hence does not support its concurrent use with first-line EGFR-TKI therapy in patients without diabetes with EGFRm NSCLC.

Metformin promotes survivin degradation through AMPK/PKA/GSK-3β-axis in non-small cell lung cancer

Metformin, a first-line antidiabetic drug, has been reported with anticancer activities in many types of cancer. However, its molecular mechanisms remain largely unknown. As a member of inhibitor of apoptosis proteins, survivin plays an important role in the regulation of cell death. In the present study, we investigated the role of survivin in metformin-induced anticancer activity in non-small cell lung cancer in vitro. Metformin mainly induced apoptotic cell death in A549 and H460 cell lines. It remarkably suppressed the expression of survivin, decreased the stability of this protein, then promoted its proteasomal degradation. Moreover, metformin greatly suppressed protein kinase A (PKA) activity and induced its downstream glycogen synthase kinase 3β (GSK-3β) activation. PKA activators, both 8-Br-cAMP and forskolin, significantly increased the expression of survivin. Consistently both GSK-3β inhibitor LiCl and siRNA restored the expression of survivin in lung cancer cells. Furthermore, metformin induced adenosine 5'-monophosphate-activated protein kinase (AMPK) activation. Suppression of the activity of AMPK with Compound C reversed the degradation of survivin induced by metformin, and meanwhile, restored the activity of PKA and GSK-3β. These results suggest that metformin kills lung cancer cells through AMPK/PKA/GSK-3β-axis-mediated survivin degradation, providing novel insights into the anticancer effects of metformin.

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

PURPOSE

Studies suggest that regular use of metformin may decrease cancer mortality. We investigated the association between diabetes medication use and cancer survival.

MATERIALS AND METHODS

The current study includes 633 breast, 890 colorectal, 824 lung, and 543 gastric cancer cases identified from participants of two population-based cohort studies in Shanghai. Information on diabetes medication use was obtained by linking to electronic medical records. The associations between diabetes medication use (metformin, sulfonylureas, and insulin) and overall and cancer-specific survival were evaluated using time-dependent Cox proportional hazards models.

RESULTS

After adjustment for clinical characteristics and treatment factors, use of metformin was associated with better overall survival among colorectal cancer patients (hazards ratio [HR], 0.55; 95% confidence interval [CI], 0.34 to 0.88) and for all four types of cancer combined (HR, 0.75; 95% CI, 0.57 to 0.98). Ever use of insulin was associated with worse survival for all cancer types combined (HR, 1.89; 95% CI, 1.57 to 2.29) and for the four cancer types individually. Similar associations were seen for diabetic patients. Sulfonylureas use was associated with worse overall survival for breast or gastric cancer (HR, 2.87; 95% CI, 1.22 to 6.80 and HR, 2.05; 95% CI, 1.09 to 3.84, respectively) among diabetic patients. Similar association patterns were observed between diabetes medication use and cancer-specific survival.

CONCLUSION

Metformin was associated with improved survival among colorectal cancer cases, while insulin use was associated with worse survival among patients of four major cancers. Further investigation on the topic is needed given the potential translational impact of these findings.

Metformin induces apoptotic cytotoxicity depending on AMPK/PKA/GSK-3β-mediated c-FLIPL degradation in non-small cell lung cancer

Background

Metformin, a first-line antidiabetic drug, has recently been reported with anticancer activities in various cancers; however, the underlying mechanisms remain elusive. The aim of the present study was to investigate the role of cellular FADD-like IL-1β-converting enzyme (FLICE)-inhibitory protein large (c-FLIP_L) in metformin-induced anticancer activity in non-small cell lung cancer (NSCLC) in vitro.

Materials and methods

Cell viability was measured by MTT assay. Quantitative real-time PCR was carried out to detect the level of mRNA of related genes. The expression of related proteins was detected by Western blot. siRNA was used to silence the expression of targeted proteins.

Results

Metformin significantly suppressed proliferation of both A549 and H460 cells in a dose-dependent manner. Mechanistic studies suggested that metformin killed NSCLC cells by inducing apoptotic cell death. Moreover, metformin greatly inhibited c-FLIP_L expression and then promoted its degradation. Furthermore, metformin significantly activated Adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) and its downstream glycogen synthase kinase 3beta (GSK-3β), block the expression of AMPK, and GSK-3β with siRNA partially reversed metformin-induced cytotoxicity and restored the expression of c-FLIP_L in lung cancer cells. Metformin also suppressed the activity of AMPK downstream protein kinase A (PKA), PKA activators, both 8-Br-cAMP and forskolin, greatly increased c-FLIP_L expression in NSCLC cells.

Conclusion

This study provided evidence that metformin killed NSCLC cells through AMPK/PKA/GSK-3β axis-mediated c-FLIP_L degradation.

Metformin-induced anticancer activities: recent insights

Metformin is a widely used antidiabetic drug, and there is evidence among diabetic patients that metformin is a chemopreventive agent against multiple cancers. There is also evidence in human studies that metformin is a cancer chemotherapeutic agent, and several clinical trials that use metformin alone or in combination with other drugs are ongoing. In vivo and in vitro cancer cell culture studies demonstrate that metformin induces both AMPK-dependent and AMPK-independent genes/pathways that result in inhibition of cancer cell growth and migration and induction of apoptosis. The effects of metformin in cancer cells resemble the patterns observed after treatment with drugs that downregulate specificity protein 1 (Sp1), Sp3 and Sp4 or by knockdown of Sp1, Sp3 and Sp4 by RNA interference. Studies in pancreatic cancer cells clearly demonstrate that metformin decreases expression of Sp1, Sp3, Sp4 and pro-oncogenic Sp-regulated genes, demonstrating that one of the underlying mechanisms of action of metformin as an anticancer agent involves targeting of Sp transcription factors. These observations are consistent with metformin-mediated effects on genes/pathways in many other tumor types.

Impact of metformin use on survival outcomes in non-small cell lung cancer treated with platinum

Preclinical evidence suggests that metformin, a widely used antidiabetic drug, may have a sensitizing effect on platinum. The purpose of this study was to evaluate the survival outcomes for non-small cell lung cancer (NSCLC) patients with type 2 diabetes mellitus (T2DM) using metformin during platinum-based chemotherapy.The clinicopathological parameters and survival data of 75 NSCLC patients with T2DM from January 2008 to December 2011 were collected and analyzed retrospectively. Patients were divided into 2 groups: metformin exposure group (n = 27) and non-metformin group (patients using other hypoglycemic agents or no drug for controlling n = 48). Univariate and multivariate analyses were performed to assess the association of metformin usage with overall survival (OS).Mean follow-up time was 58.7 months. The mean survival time was 36.74 months in the metformin group and 40.21 months in the non-metformin group. There was no significant difference in survival time between the 2 groups (P = .661). After adjusting gender, age, smoking status, tumor stage, tumor histology, and differentiation, multivariate analysis showed that metformin was not associated with the OS in NSCLC patients treated with concurrent platinum-based chemotherapy (hazard ratio: 1.071, 95% confidence interval: 0.577-1.986, P = .828).Our results indicated that metformin exposure had no significant effect on OS in NSCLC patients treated with platinum-based chemotherapy. Further studies are warranted to evaluate whether metformin could affect the survival of NSCLC patients treated with platinum-based chemotherapy.

The antineoplastic drug metformin downregulates YAP by interfering with IRF-1 binding to the YAP promoter in NSCLC

Background

Activation of the oncogene YAP has been shown to be related to lung cancer progression and associates with poor prognosis and metastasis. Metformin is a drug commonly used in the treatment of diabetes and with anticancer activity. However, the mechanism through which metformin inhibits tumorigenesis via YAP is poorly understood.

Methods

The mRNA and protein expressions were analyzed by RT-PCR and western blot. The cellular proliferation was detected by CCK8 and MTT. The cell migration and invasion growth were analyzed by wound healing assay and transwell assay. The activities of promoter were analyzed by luciferase reporter assay. Chromatin immunoprecipitation detected the combining ability of IRF-1 and 5′UTR-YAP.

Findings

Our immunohistochemistry staining and RT-PCR assays showed that the expression of YAP was higher in lung carcinoma samples. Interestingly, metformin was able to downregulate YAP mRNA and protein expression in lung cancer cells. Mechanistically, we found that metformin depressed YAP promoter by competing with the binding of the transcription factor IRF-1 in lung cancer cells. Moreover, combination of metformin and verteporfin synergistically inhibits cell proliferation, promotes apoptosis and suppresses cell migration/invasion by downregulating YAP, therefore reduces the side effects caused by their single use and improve the quality of life for patients with lung cancer.

Interpretation

we concluded that metformin depresses YAP promoter by interfering with the binding of the transcription factor IRF-1. Importantly, verteporfin sensitizes metformin-induced the depression of YAP and inhibition of cell growth and invasion in lung cancer cells.

Fund

This work was supported by National Natural Science Foundation of China (No.31801085), the Science and Technology Development Foundation of Yantai (2015ZH082), Natural Science Foundation of Shandong Province (ZR2018QH004, ZR2016HB55, ZR2017PH067 and ZR2017MH125), and Research Foundation of Binzhou Medical University (BY2015KYQD29 and BY2015KJ14).

Metformin in cancer

Metformin is a lipophilic biguanide which inhibits hepatic gluconeogenesis and improves peripheral utilization of glucose. It is the first line pharmacotherapy for glucose control in patients with Type 2 diabetes due to its safety, efficacy and tolerability. Metformin exhibits pleotropic effects, which may have beneficial effects on a variety of tissues independent of glucose control. A potential anti-tumourigenic effect of metformin may be mediated by its role in activating AMP-kinase, which in turn inhibits mammalian target of rapamycin (mTOR). Non-AMPK dependent protective pathways may include reduction of insulin, insulin-like growth factor-1, leptin, inflammatory pathways and potentiation of adiponectin, all of which may have a role in tumourigenesis. A role in inhibiting cancer stem cells is also postulated. A number of large scale observational and cohort studies suggest metformin is associated with a reduced risk of a number of cancers, although the data is not conclusive. Recent randomised studies reporting use of metformin in treatment of cancer have revealed mixed results, and the results of much larger randomised trials of metformin as an adjuvant therapy in breast and colorectal cancers are awaited.

Inhalational supplementation of metformin butyrate: A strategy for prevention and cure of various pulmonary disorders

The management of chronic lung diseases such as cancer, asthma, COPD and pulmonary hypertension remains unsatisfactory till date, and several strategies are being tried to control the same. Metformin, a popular anti-diabetic drug has shown promising effects in pre-clinical studies and has been subject to several trials in patients with debilitating pulmonary diseases. However, the clinical evidence for the use of metformin in these conditions is disappointing. Recent observations suggest that metformin use in diabetic patients is associated with an increase in butyrate-producing bacteria in the gut microbiome. Butyrate, similar to metformin, shows beneficial effects in pathological conditions found in pulmonary diseases. Further, the pharmacokinetic data of metformin suggests that metformin is predominantly concentrated in the gut, even after absorption. Butyrate, on the other hand, has a short half-life and thus oral supplementation of butyrate and metformin is unlikely to result in high concentrations of these drugs in the lung. In this paper, we review the pre-clinical studies of metformin and butyrate pertaining to pathologies commonly encountered in chronic lung diseases and underscore the need to administer these drugs directly to the lung via the inhalational route.

The regulatory effects of metformin on the [SNAIL/miR-34]:[ZEB/miR-200] system in the epithelial-mesenchymal transition(EMT) for colorectal cancer(CRC)

The epithelial-mesenchymal transition (EMT) plays a critical role in cancer progression, metastasis and drug resistance. The transcription factor(TF) and microRNA (miR) chimeric [SNAIL/miR-34]:[ZEB/miR-200] unit is the core regulatory system for the EMT process. Here, we proposed to assess the anti-EMT abilities and explore the inherent pharmacological mechanisms of the classic hypoglycaemic agent metformin for colorectal cancer(CRC). For the EMT model, the TGF-β-induced CRC cell lines SW480 and HCT116 were treated with metformin. The viability, migration and invasion abilities of the cells were evaluated with the Cell Counting Kit-8, wound-healing and trans-well assay. The alterations of the [SNAIL/miR-34]:[ZEB/miR-200] system and the EMT markers E-cadherin and vimentin were detected by western blot, qPCR and immunofluorescent staining. Metformin exhibited inhibitory effects on the proliferation, migration and invasion of the CRC SW480 cells. The up-regulation of E-cadherin and the down-regulation of vimentin for both SW480 and HCT116 cells revealed the anti-EMT abilities of metformin. For the [SNAIL/miR-34]:[ZEB/miR-200] system, metformin increased miR-200a, miR-200c and miR-429 levels and decreased miR-34a, SNAIL1 and ZEB1 levels in the TGF-β-induced EMT. From immunofluorescence, we observed increased E-cadherin and ZEB1 co-expression in metformin-treated cells. Metformin may perform bidirectional regulations of the [SNAIL/miR-34]:[ZEB/miR-200] system in the EMT process for colorectal cancer. Such regulation is expressed as the inhibition of EMT in general as well as an increased higher proportion of E/M hybrid cells in the total population.

Effect of hypoglycemic agents on survival outcomes of lung cancer patients with diabetes mellitus: A meta-analysis

BACKGROUND

To assess the association between hypoglycemic agents and prognosis of lung cancer patients with diabetes.

METHODS

A comprehensive literature search was performed in PubMed, Web of Science, Embase, and Cochrane Library until May 2017. The search yielded 2593 unique citations, of which 18 articles met inclusion criteria. The hazard ratios (HRs) and 95% confidence intervals (95% CIs) were calculated by a fixed-effects or random-effects model.

RESULTS

The pooled HRs favoring metformin users were 0.77 for overall survival (OS) (n = 15, 95% CI: 0.68-0.86) and 0.50 for disease-free survival (n = 5, 95% CI: 0.39-0.64). One study assessed the relationship between metformin and cancer-specific survival (CSS), reporting no significant results. No significant association between insulin and OS (n = 2, HR: 0.95, 95% CI: 0.79-1.13) or CSS (n = 2, HR: 1.03, 95% CI: 0.76-1.41) was noted. One study evaluated association of sulfonylureas with lung cancer survival and reported no clinical benefit (HR: 1.10, 95% CI: 0.87-1.40). One study reported no association of thiazolidinediones with lung cancer survival (HR: 1.04, 95% CI: 0.65-1.66).

CONCLUSIONS

This meta-analysis demonstrated that metformin exposure might improve survival outcomes in lung cancer patients with diabetes.

The Clinical Effect of Metformin on the Survival of Lung Cancer Patients with Diabetes: A Comprehensive Systematic Review and Meta-analysis of Retrospective Studies

Preclinical investigations have revealed an anti-cancer effect of metformin. Several studies of metformin treatment have demonstrated the improved clinical outcomes of lung cancer patients with diabetes; however, the results have been inconsistent among studies. Our systematic review and meta-analysis aimed to summarize the up-to-date effects of metformin on diabetic lung cancer patients. A systematic search was performed for studies published. Then, these studies were evaluated for inclusion, and relevant data was extracted. The summary risk estimates for the associations of metformin treatment with overall survival (OS) and progression-free survival (PFS) were analyzed using random/fixed-effects models. Analyses stratified by histological type were also conducted. Based on the 10 studies included in our analysis, metformin treatment was found to significantly improve survival, corresponding to reductions of 23% and 47% in OS [hazard ratio (HR)=0.77, 95% confidence interval (95%CI)=0.66-0.9, p=0.001] and PFS (HR=0.53, 95%CI=0.41-0.68, p<0.001), respectively. In addition, significant improvements in the OS for non-small cell lung cancer (NSCLC) (HR=0.77, 95%CI=0.71-0.84, p=0.002) and small cell lung cancer (SCLC) (HR=0.52, 95%CI=0.29-0.91, p=0.022) were observed in association with metformin treatment in analysis stratified by histological type. This stratified analysis also revealed a significant improvement in PFS for both NSCLC (HR=0.53, 95%CI=0.39-0.71, p<0.001) and SCLC (HR=0.54, 95%CI=0.34-0.84, p=0.007). We found that metformin treatment significantly improved the OS and PFS of diabetic lung cancer patients, and our findings suggest that metformin might be an effective treatment option for diabetic patients with lung cancer.