Diabetes is not associated with longer survival in patients with lung cancer

Will We Unlock the Benefit of Metformin for Patients with Lung Cancer? Lessons from Current Evidence and New Hypotheses

Metformin has been under basic and clinical study as an oncological repurposing pharmacological agent for several years, stemming from observational studies which consistently evidenced that subjects who were treated with metformin had a reduced risk for development of cancer throughout their lives, as well as improved survival outcomes when diagnosed with neoplastic diseases. As a result, several basic science studies have attempted to dissect the relationship between metformin’s metabolic mechanism of action and antineoplastic cellular signaling pathways. Evidence in this regard was compelling enough that a myriad of randomized clinical trials was planned and conducted in order to establish the effect of metformin treatment for patients with diverse neoplasms, including lung cancer. As with most novel antineoplastic agents, early results from these studies have been mostly discouraging, though a recent analysis that incorporated body mass index may provide significant information regarding which patient subgroups might derive the most benefit from the addition of metformin to their anticancer treatment. Much in line with the current pipeline for anticancer agents, it appears that the benefit of metformin may be circumscribed to a specific patient subgroup. If so, addition of metformin to antineoplastic agents could prove one of the most cost-effective interventions proposed in the context of precision oncology. Currently published reviews mostly rely on a widely questioned mechanism of action by metformin, which fails to consider the differential effects of the drug in lean vs. obese subjects. In this review, we analyze the pre-clinical and clinical information available to date regarding the use of metformin in various subtypes of lung cancer and, further, we present evidence as to the differential metabolic effects of metformin in lean and obese subjects where, paradoxically, the obese subjects have reported more benefit with the addition of metformin treatment. The novel mechanisms of action described for this biguanide may explain the different results observed in clinical trials published in the last decade. Lastly, we present novel hypothesis regarding potential biomarkers to identify who might reap benefit from this intervention, including the role of prolyl hydroxylase domain 3 (PHD3) expression to modify metabolic phenotypes in malignant diseases.

Diabetic lung disease: fact or fiction?

Diabetes mellitus is a chronic, progressive, incompletely understood metabolic disorder whose prevalence has been increasing steadily worldwide. Even though little attention has been paid to lung disorders in the context of diabetes, its prevalence has recently been challenged by newer studies of disease development. In this review, we summarize and discuss the role of diabetes mellitus involved in the progression of pulmonary diseases, with the main focus on pulmonary fibrosis, which represents a chronic and progressive disease with high mortality and limited therapeutic options.

Survival of patients with lung cancer and diabetes mellitus

Diabetes mellitus (DM) and lung cancer are two highly globally prevalent diseases. The current study aimed to determine the prognostic significance of DM comorbidity in patients with lung cancer. All patients diagnosed at Tsukuba Medical Center Hospital and Mito Medical Center, (University of Tsukuba, Ibaraki, Japan) between April 1999 and March 2012 were followed up to 2015 and were retrospectively analyzed. DM was defined as a fasting plasma glucose (FPG) level ≥126 mg/dl, a non-FPG level ≥200 mg/dl, or a hemoglobin (Hb) A1c level ≥6.5%. Additionally, patients taking medication for diabetes and those with a history of using such medications were also classified as having DM. During the study period, 1,798 patients with lung cancer were diagnosed. Within this cohort, 338 (18.8%) were classed as having lung cancer and DM. In univariate and multivariate analyses, smoking status, poorer performance status, small cell lung cancer pathology, metastatic disease and supportive care were the only unfavorable prognostic factors (all P=0.001). Additionally, multivariate analysis revealed that existing DM was an unfavorable disease-modifying factor (P=0.03612). Therefore, DM comorbidity adversely affects lung cancer outcomes. To provide prolonged quality of survival, appropriate pre-evaluation of lung cancer, as well as the patient's medical condition, including DM, is required.

Metformin use and its effect on survival in diabetic patients with advanced non-small cell lung cancer

Background

Previous population-based studies have demonstrated an association between metformin use and improved survival among diabetic patients with cancer. We sought to analyze the effects of diabetes and its treatment in terms of the survival of patients with lung cancer.

Methods

Overall, 1106 patients with non-small cell lung cancer (94.3 % with stage IV disease) were included. The outcomes were compared between the patients with (n = 186) and without diabetes (n = 920). The characteristics associated with antidiabetic treatment and proper glycemic control (defined as a mean plasma glucose <130 mg/dL) were examined at diagnosis. The overall survivals (OSs) of the different patient populations were analyzed using Kaplan-Meier curves, and a multivariate Cox proportional hazard model was used to determine the influences of the patient and tumor characteristics on survival.

Results

The OS for the entire population was 18.3 months (95 % CI 16.1-20.4). There was no difference in the OSs of the diabetic and non-diabetic patients (18.5 vs 16.4 months, p = 0.62). The diabetic patients taking metformin exhibited a superior OS than did those on other antidiabetic treatments (25.6 vs 13.2 months, p = 0.017). Those with proper glycemic control had a better OS than did those without proper glycemic control and the non-diabetics (40.5 vs 13.2 and 18.5 months, respectively, p < 0.001). Both the use of metformin (HR 0.53, p < 0.0001 and HR 0.57, p = 0.017, respectively) and proper glycemic control (HR 0.49, p < 0.0001 and HR 0.40, p = 0.002, respectively) were significant protective factors in all and only diabetic patients, respectively.

Conclusions

The diabetic patients with proper glycemic control exhibited a better OS than did those without proper glycemic control and even exhibited a better OS than did the patients without diabetes mellitus. Metformin use was independently associated with a better OS.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2658-6) contains supplementary material, which is available to authorized users.

Prognostic significance of diabetes mellitus in locally advanced non-small cell lung cancer

Background

To investigate the prognostic significance of patient characteristics and clinical laboratory test results in locally advanced non-small cell lung cancer (NSCLC), and in particular the impact of diabetes mellitus (DM) on the survival of patients who underwent chemoradiotherapy.

Methods

We retrospectively reviewed 159 patients with locally advanced NSCLC with a focus on DM and other potential prognostic factors, using the log-rank test, and univariate and multivariate analyses to assess their association with survival.

Result

Five significant prognostic factors were identified in univariate analysis: stage (p < 0.001), DM (p = 0.04), hemoglobin levels (p = 0.003), serum albumin (p <0.001) and lactate dehydrogenase (LDH) levels (p = 0.01). Furthermore, among the factors tested using Fisher's exact test and the Wilcoxon rank sum test, gender (p = 0.019) and plasma glucose level (p <0.001) were found to have prognostic significance. Multivariate analysis showed that stage, DM, serum albumin and LDH levels were independent prognostic factors for survival (p = 0.007, p = 0.024, p = 0.007 and p = 0.005, respectively).

Conclusions

The presence of DM at the time of diagnosis was identified as an independent and significant prognostic factor for predicting negative outcome in locally advanced NSCLC patients.

Metformin and Not Diabetes Influences the Survival of Resected Early Stage NSCLC Patients

BACKGROUND

Published data suggest that diabetes influences survival of patients with lung cancer. The anti-cancer effect of metformin confounds this association. We sought to study the association of diabetes and metformin with survival in patients undergoing resection of stage I non-small cell lung cancer (NSCLC).

METHODS

Pathologic stage I NSCLC patients undergoing anatomic resection from 2002 to 2011 were studied. A diagnosis of diabetes and diabetic medication use were identified through records. Univariate and multivariate analyses examined the association of diabetes and metformin usage with overall survival (OS).

RESULTS

409 eligible patients were included in the analysis - excluding patients with neoadjuvant therapy, more than one lung cancer, or resection less than lobectomy. 71 (17.4%) patients were diabetics and 41 (10.0%) used metformin. With a median follow up of 44 months, univariate analysis demonstrates that diabetes had no effect on OS (P=0.75); however, metformin use was associated with improved OS (median survival not reached vs. 60 months; P=0.02). Metformin use remained an important predictor of good survival in multivariate analysis (HR=3.08; P<0.01) after adjusting for age, gender, pathologic stage, histology and smoking status.

CONCLUSION

Metformin use rather than diabetes is associated with improved long-term survival in Stage I NSCLC patients.

Is diabetes mellitus a negative prognostic factor for the treatment of advanced non-small-cell lung cancer?

BACKGROUND

It has been demonstrated that there are a lot of different prognostic factors which are worthy of consideration whereas diabetes mellitus (DM) has not been clearly or consistently identified as a prognostic value in advanced non-small cell lung cancer (NSCLC). The aim of this study was to investigate the prognostic significance of the characteristics of patients in advanced NSCLC. Specifically, we investigated the impact of DM for progression-free survival (PFS) and overall survival (OS) in patients receiving first-line platinum-based doublets chemotherapy.

METHODS

We retrospectively reviewed 442 patients with advanced NSCLC. DM and other potential prognostic variables were chosen for analysis in this study. Univariate and multivariate analyses were conducted to identify prognostic factors associated with survival.

RESULT

The results of univariate analysis for OS were identified as having prognostic significance: performance status (p<0.001), stage (p<0.001), DM (p<0.001), liver metastasis (p=0.02) and brain metastasis (p<0.001). Stage, diabetes mellitus, and liver metastasis were identified as having prognostic significance for PFS. Multivariate analysis showed that poor performance status, presence of DM and advanced stage were considered independent negative prognostic factors for OS (p 0.001, p<0.001 and p<0.001 respectively). Furthermore, DM and stage were considered independent negative prognostic factors for PFS (p 0.005 and p 0.001 respectively).

CONCLUSION

In conclusion, DM at the time of diagnosis was associated with the negative prognostic importance for PFS and OS in the advanced stage patients who were receiving first-line platinum-based doublets chemotherapy. In addition poor performance status and advanced stage were identified as negative prognostic factors.

Increased lung cancer risk among patients with pneumococcal pneumonia: a nationwide population-based cohort study

BACKGROUND

The possible effects of pneumonia on subsequent lung cancer have been reported, but no relevant publications have focused on the association between pneumococcal pneumonia and lung cancer. The purpose of this study was to perform a nationwide population-based cohort study to investigate the risk of lung cancer after pneumococcus infection.

METHODS

This nationwide population-based cohort study was based on data obtained from the Taiwan National Health Insurance Database. In total, 22,034 pneumococcal pneumonia patients and 88,136 controls, matched for age and sex, were recruited for the study from 1997 to 2010.

RESULTS

The incidence rate of lung cancer (28.2 per 1,000 person-years) was significantly higher in pneumococcal pneumonia patients than in controls (8.7 per 1,000 person-years; incidence rate ratio, 3.25; 95 % confidence interval, 3.09-3.42; p < 0.001). Cox proportional hazards regression analysis showed a hazard ratio of 4.24 (95 % confidence interval, 3.96-4.55) for the pneumococcal pneumonia cohort after adjustment for age, gender, and comorbidities.

CONCLUSIONS

Pneumococcal pneumonia is associated with an increased risk of lung cancer. Thus, physicians should remain aware of this association when assessing patients with pneumococcal pneumonia.

Type 2 diabetes and/or its treatment leads to less cognitive impairment in Alzheimer's disease patients

AIM

To evaluate the cognitive performance of a homogeneous population of Alzheimer's disease (AD), non-demented Type 2 Diabetes Mellitus (DIAB), demented with concomitant diseases (AD+DIAB) and healthy control subjects. AD is a progressive dementia disorder characterized clinically by impairment of memory, cognition and behavior. Recently, a major research interest in AD has been placed on early evaluation. Diabetes is one of the clinical conditions that represent the greatest risk of developing oxidative stress and dementia. Glucose overload, leading to the development of impaired-induced insulin secretion in DIAB and has been suggested to slow or deter AD pathogenesis.

METHODS

The degree of cognitive impairment was determined on the Alzheimer Disease Assessment Scale-Cognitive (ADAS-Cog) and the Folstein's Mini Mental State Examination (MMSE); the severity of dementia was quantified applying the Clinical Dementia Rating (CDR) test; the Hamilton test was employed to evaluate depressive conditions; the final population studied was 101 subjects.

RESULTS

The cognitive deterioration is statistically significantly lower (p<0.05) in AD+DIAB patients as compared with AD patients.

CONCLUSIONS

In this longitudinal study the superimposed diabetic condition was associated with a lower rate of cognitive decline, while diabetic non-demented patients and controls present normal scores.

Prolonged survival in patients with lung cancer with diabetes mellitus

INTRODUCTION

Patients with lung cancer have a high frequency of comorbidity. Data on the impact of diabetes mellitus, the most frequent endocrine disorder, on the prognosis of lung cancer are conflicting. The aim was to investigate the impact of diabetes mellitus on survival in lung cancer.

METHOD

We analyzed data from a cohort, the Nord-Trøndelag Health Study (HUNT study) linked to the Norwegian Cancer Registry and controlled the results using two lung cancer studies, the Pemetrexed Gemcitabine study and the Norwegian Lung Cancer Biobank. Survival in lung cancer with and without diabetes mellitus was compared using the Kaplan-Meier method and Cox regression model for each study and the studies combined.

RESULTS

One thousand six hundred seventy-seven cases of lung cancer were included, 1031 from HUNT study, 436 from the Pemetrexed Gemcitabine study, and 210 from the Norwegian Lung Cancer Biobank registry, and among these 77 patients had diabetes mellitus. In the combined analysis, patients with lung cancer with diabetes mellitus had increased survival compared with those without (p = 0.005). The 1-, 2-, and 3-year survival in patients with lung cancer with and without diabetes mellitus were 43% versus 28%, 19% versus 11%, and 3% versus 1%, respectively. Adjusting for age, gender, histology, and stage of disease in the Cox regression model, the hazard ratio for survival in patients with lung cancer with diabetes mellitus was 0.55 (95% CI, 0.41-0.75) as compared with without.

CONCLUSION

Patients with lung cancer with diabetes mellitus have an increased survival compared with those without diabetes mellitus.

Increased lung cancer risk among patients with pulmonary tuberculosis: a population cohort study

INTRODUCTION

Given one third of the human population have been infected with tuberculosis, it is important to delineate the relationship between tuberculosis and lung cancer. This study explored whether contracting pulmonary tuberculosis is associated with an increased risk of developing lung cancers.

METHODS

In a cohort of 716,872 insured subjects, free from cancers, aged 20 years and older, 4480 patients with newly diagnosed tuberculosis were identified from the universal insurance claims in 1998-2000 and tracked until 2007 with the remaining insured without tuberculosis. We compared the incidence of lung cancers between the two cohorts and measured the associated hazard of developing lung cancer.

RESULTS

The incidence of lung cancers was approximately 11-fold higher in the cohort of patients with tuberculosis than nontuberculosis subjects (26.3 versus 2.41 per 10,000 person-years). Cox proportional hazard regression analysis showed a hazard ratio of 4.37 (95% confidence interval [CI]: 3.56-5.36) for the tuberculosis cohort after adjustment for the sociodemographic variables or 3.32 (95% CI: 2.70-4.09) after further adjustment for chronic obstructive pulmonary disease (COPD), smoking-related cancers (other than lung cancer), etc. The hazard ratio increased to 6.22 (95% CI: 4.87-7.94) with the combined effect with COPD or to 15.5 (95% CI: 2.17-110) with the combined effect with other smoking-related cancers.

CONCLUSIONS

This study provides a compelling evidence of increased lung cancer risk among individuals with tuberculosis. The risk may increase further with coexisting COPD or other smoking-related cancers.

Small vessel ischemic disease of the brain and brain metastases in lung cancer patients

Background

Brain metastases occur commonly in patients with lung cancer. Small vessel ischemic disease is frequently found when imaging the brain to detect metastases. We aimed to determine if the presence of small vessel ischemic disease (SVID) of the brain is protective against the development of brain metastases in lung cancer patients.

Methodology/Principal Findings

A retrospective cohort of 523 patients with biopsy confirmed lung cancer who had received magnetic resonance imaging of the brain as part of their standard initial staging evaluation was reviewed. Information collected included demographics, comorbidities, details of the lung cancer, and the presence of SVID of the brain. A portion of the cohort had the degree of SVID graded. The primary outcome measure was the portion of study subjects with and without SVID of the brain who had evidence of brain metastases at the time of initial staging of their lung cancer.109 patients (20.8%) had evidence of brain metastases at presentation and 345 (66.0%) had evidence of SVID. 13.9% of those with SVID and 34.3% of those without SVID presented with brain metastases (p<0.0001). In a model including age, diabetes mellitus, hypertension, hyperlipidemia, and tobacco use, SVID of the brain was found to be the only protective factor against the development of brain metastases, with an OR of 0.31 (0.20, 0.48; p<0.001). The grade of SVID was higher in those without brain metastases.

Conclusions/Significance

These findings suggest that vascular changes in the brain are protective against the development of brain metastases in lung cancer patients.

Association of diabetes with survival among cohorts of Indigenous and non-Indigenous Australians with cancer

BACKGROUND

The association between diabetes and cancer incidence has been well documented, but relatively little research has been undertaken on the potential influence of diabetes on cancer survival and the research that is available has produced inconsistent results. Because Indigenous Australians have a high prevalence of diabetes, we assessed survival, stratified by diabetes, among Indigenous Australian cancer patients. We also assessed survival, stratified by diabetes, amongst a cohort of non-Indigenous Australian cancer patients.

METHODS

All-cause survival and cancer-specific survival in diabetic versus non-diabetic cancer patients were assessed in Indigenous and non-Indigenous cohorts separately, using proportional hazards models.

FINDINGS

Indigenous cancer patients with diabetes (n = 140) had an overall survival disadvantage compared to Indigenous cancer patients without diabetes (n = 675) with all-cause Hazard Ratio (HR) = 1.4 (95% CI 1.1-1.8) adjusted for age, sex, and cancer site. After further adjustment to take into account the greater number of non-cancer deaths and co-morbidities in Indigenous cancer patients with diabetes, and their later stage at cancer diagnosis with less cancer treatment, there was no residual difference in cancer-specific survival compared to Indigenous cancer patients without diabetes (cancer-specific HR = 1.0, 95% CI 0.8, 1.3). Fewer non-Indigenous cancer patients had diabetes (n = 52) and they showed no differences in survival compared to their counterparts without diabetes.

INTERPRETATION

The poorer survival of Indigenous Australian cancer patients with diabetes was due to more non-cancer deaths, later stage at cancer diagnosis, less cancer treatment, and more co-morbidities than Indigenous Australian cancer patients without diabetes. In contrast, diabetes did not appear to affect survival in non-Indigenous Australians with cancer, either because there were too few to detect a moderate deleterious effect or because there was no association. Understanding the relation between diabetes and cancer treatment and survival is important because both diabetes and cancer are relatively common diseases, increasingly likely to co-exist.