Body mass index and risk of lung cancer: Systematic review and dose-response meta-analysis

The Association between Dyslipidemia and Pulmonary Diseases

Dyslipidemia is one of the most common diseases worldwide. As a component of metabolic syndrome, the prevalence and mechanism by which dyslipidemia promotes cardiovascular diseases has been well studied, although the relationship between pulmonary diseases is not well understood. Because the lung is a respiratory organ with a large surface area and is exposed to the environment outside the body, it continuously inhales various substances. As a result, pulmonary diseases have a vast diversity, including chronic inflammatory diseases, allergic diseases, cancers, and infectious diseases. Recently, growing evidence has suggested that dyslipidemia plays a role in the pathogenesis and prognosis of various pulmonary diseases. We herein review the current understanding of the relationship between dyslipidemia and pulmonary diseases, including chronic obstructive pulmonary diseases, asthma, and lung cancer, and infectious pulmonary diseases, including community-acquired pneumonia, tuberculosis, nontuberculous mycobacterial pulmonary disease, and COVID-19. In addition, we focus on recent evidence of the utility of statins, specifically 3-hydroxy-3-methylglutaryl-coA reductase inhibitors, in the prevention and treatment of the various pulmonary diseases described above.

The mediating role of health behaviors in the association between depression, anxiety and cancer incidence: an individual participant data meta-analysis

BACKGROUND

Although behavioral mechanisms in the association among depression, anxiety, and cancer are plausible, few studies have empirically studied mediation by health behaviors. We aimed to examine the mediating role of several health behaviors in the associations among depression, anxiety, and the incidence of various cancer types (overall, breast, prostate, lung, colorectal, smoking-related, and alcohol-related cancers).

METHODS

Two-stage individual participant data meta-analyses were performed based on 18 cohorts within the Psychosocial Factors and Cancer Incidence consortium that had a measure of depression or anxiety (N = 319 613, cancer incidence = 25 803). Health behaviors included smoking, physical inactivity, alcohol use, body mass index (BMI), sedentary behavior, and sleep duration and quality. In stage one, path-specific regression estimates were obtained in each cohort. In stage two, cohort-specific estimates were pooled using random-effects multivariate meta-analysis, and natural indirect effects (i.e. mediating effects) were calculated as hazard ratios (HRs).

RESULTS

Smoking (HRs range 1.04-1.10) and physical inactivity (HRs range 1.01-1.02) significantly mediated the associations among depression, anxiety, and lung cancer. Smoking was also a mediator for smoking-related cancers (HRs range 1.03-1.06). There was mediation by health behaviors, especially smoking, physical inactivity, alcohol use, and a higher BMI, in the associations among depression, anxiety, and overall cancer or other types of cancer, but effects were small (HRs generally below 1.01).

CONCLUSIONS

Smoking constitutes a mediating pathway linking depression and anxiety to lung cancer and smoking-related cancers. Our findings underline the importance of smoking cessation interventions for persons with depression or anxiety.

Association between insulin resistance, metabolic syndrome and its components and lung cancer: a systematic review and meta-analysis

BACKGROUND

A growing body of evidence points to the association between insulin resistance (IR), metabolic syndrome (MetS) and its components and lung cancer incidence, but remains controversial and unknown.

METHODS

A systematic search was conducted through PubMed, Embase, Cochrane Library, the China National Knowledge Infrastructure (CNKI) and Wanfang databases for the corresponding studies. Each study reported the risk estimate and 95% confidence intervals (CI) for lung cancer, and a fixed effects model or random effects model was used for outcome.

RESULTS

We included 31 publications involving 6,589,383 people with 62,246 cases of lung cancer. Diabetes mellitus (DM) (RR = 1.11, 95% CI  1.06-1.16, P = 0.000) and IR (RR = 2.35, 95% CI  1.55-3.58, P = 0.000) showed a positive association with lung cancer risk. BMI (RR = 0.66, 95% CI  0.54-0.81, P = 0.000) and HDL-C (RR = 0.88, 95% CI  0.79-0.97, P = 0.010) were negatively correlated with lung cancer. MetS(RR = 0.99, 95% CI  0.90-1.09, P = 0.801), TC (RR = 0.93, 95% CI  0.81-1.06, P = 0.274), TG (RR = 0.99, 95% CI  0.88-1.12,P = 0.884), LDL-C (RR = 1.01, 95% CI  0.87-1.16, P = 0.928), hypertension (RR = 1.01, 95% CI  0.88-1.15, P = 0.928), FBG (RR = 1.02, 95% CI  0.92-1.13, P = 0.677) and obesity (RR = 1.11, 95% CI  0.92-1.35, P = 0.280) were not associated with lung cancer.

CONCLUSION

Our study showed that the risk of lung cancer is correlated with DM, IR, BMI, and HDL-C. Timely control of these metabolic disorders may have a positive effect on preventing lung cancer. Trial registration Our study has been registered in the Prospective Register of Systematic Reviews (PROSPERO), ID: CRD42023390710.

Obesity and lung cancer - is programmed death ligand-1 (PD-1L) expression a connection?

Introduction

In this retrospective study, the authors evaluated whether obesity-induced immunomodulation impacts the expression of programmed death ligand-1 (PD-1L) in lung cancer cells.Methods: A retrospective cross-sectional study was performed. The study included 67 patients. The data did not have a normal distribution.

Results

For women, using ANOVA test (p = 0.050) with post-hoc analysis, a statistically significant difference in expression was found between women with overweight and women with normal weight (p = 0.040).

Conclusions

Apart from the above, the authors did not find any statistically significant correlation between PD-1L expression on lung cancer cells and body mass index, either in the whole group or in histological subgroups.

Association between metabolically healthy obesity and metastasis in lung cancer patients - a systematic review and meta-analysis

Background

Many clinical trials have looked at the relationship between obesity and lung cancer (LC), however, there is scarcity of literature specifically addressing the association between metabolically healthy obesity and metastasis in LC patients. To address this gap in the body of evidence, the study was conducted to observe the association between metabolically healthy obesity and metastasis in LC patients.

Methods

We conducted a pre-registered systematic review by searching six major online databases to identify studies relevant related to our investigation, in adherence with the PRISMA guidelines. A proper data extraction protocol was further established to synthesize the findings from the selected papers through a meta-analysis.

Results

Eleven (11) studies met the requisite selection criterion and were included in the study. A random-effect model was used. Obesity was found to have a significant impact on readmission in LC patients. The combined analysis showed a significant effect size of 0.08 (95% CI 0.07 to 0.08), indicating a noticeable impact of obesity. It was also assessed that obese individuals had a 34% reduced risk of LC compared to normal weight individuals. Obesity was associated with a lower risk of surgical complications with a pooled risk ratio of 0.13 (95% CI 0.12 to 0.14). A statistically significant decreased risk of LC (pooled RR = 0.72, 95% CI: 0.68 to 0.77) was also observed in the obese individuals.

Conclusion

The analysis reveals that obesity is associated with a noticeable increase in readmissions, although the impact on LC risk itself is negligible. Moreover, obesity appears to have a beneficial effect by reducing the risk of surgical complications. These results highlight the complex relationship between the two aforementioned factors, emphasizing the importance of considering obesity as a significant factor in patient management and healthcare decision-making.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42023427612.

EGCG alleviates obesity-exacerbated lung cancer progression by STAT1/SLC7A11 pathway and gut microbiota

Leptin is a nutritional cytokine, and it is closely related to the progression of cancer. However, the detailed effect of leptin in lung cancer remains poorly known. We found leptin-induced A549 cell proliferation, migration, and invasion, which was reversed by epigallocatechin gallate (EGCG) from green tea. Currently, we found that leptin-triggered M2 polarization of tumor-associated macrophages was inhibited by EGCG. Then, to investigate the underlying mechanism effect of leptin on A549 cells was studied. Aberrant activities of STAT1 are implicated in cancer development. Based on the cancer genome atlas data, STAT1 acted as an oncogene in lung cancer and EGCG greatly reduced STAT1 expression in A549 cells. Ferroptosis is an iron-dependent nonapoptotic cell death. STAT1 served as a transcriptional activator for SLC7A11. EGCG restrained lung cancer cell growth induced by leptin via targeting STAT1-SLC7A11 mediated ferroptosis. A high-fat diet (HFD) feeding condition was combined with a multi-dose urethane-induced lung tumorigenesis model using C57BL/6J mice. Obesity was induced with a 60 kcal% HFD feeding. Serum leptin levels increased in urethane-administered and HFD-fed mice. Compared to the control diet-fed mice, the HFD-fed mice exhibited increased lung tumor burden and typical pro-tumorigenic STAT1 activation in lung tissues after urethane administration. In addition, HFD alters the gut microbiome by decreasing the abundance of Clostridia and by increasing the abundance of Deltaproteobacteria and Epsilonproteobacteria while EGCG exhibited a reversed effect. These findings suggested that leptin promoted the development of lung tumorigenesis in vitro and in vivo via mediating activation of the STAT-SLC7A11 pathway and gut microbiota.

The global burden of lung cancer: current status and future trends

Lung cancer is the leading cause of cancer-related death worldwide. However, lung cancer incidence and mortality rates differ substantially across the world, reflecting varying patterns of tobacco smoking, exposure to environmental risk factors and genetics. Tobacco smoking is the leading risk factor for lung cancer. Lung cancer incidence largely reflects trends in smoking patterns, which generally vary by sex and economic development. For this reason, tobacco control campaigns are a central part of global strategies designed to reduce lung cancer mortality. Environmental and occupational lung cancer risk factors, such as unprocessed biomass fuels, asbestos, arsenic and radon, can also contribute to lung cancer incidence in certain parts of the world. Over the past decade, large-cohort clinical studies have established that low-dose CT screening reduces lung cancer mortality, largely owing to increased diagnosis and treatment at earlier disease stages. These data have led to recommendations that individuals with a high risk of lung cancer undergo screening in several economically developed countries and increased implementation of screening worldwide. In this Review, we provide an overview of the global epidemiology of lung cancer. Lung cancer risk factors and global risk reduction efforts are also discussed. Finally, we summarize lung cancer screening policies and their implementation worldwide.

Overall and abdominal obesity and risks of all-cause and cause-specific mortality in Korean adults: a pooled analysis of three population-based prospective cohorts

BACKGROUND

Studies found a J-shaped association between body mass index (BMI) and mortality. However, it is unclear whether the association is driven by biases, particularly confounding by fat-free mass.

METHODS

We conducted an individual-level pooled analysis of three cohorts of Korean adults (aged ≥ 40 years; n = 153 248). Mortality was followed up through December 2019. Anthropometric data were directly measured at baseline. Fat and fat-free mass were predicted using validated prediction models. Using Cox proportional hazards models, we estimated the associations of BMI and waist circumference (WC) with all-cause and cause-specific mortality. To account for biases, we excluded participants aged ≥ 70 years, deaths that occurred within 5 years of follow-up and ever smokers, and adjusted for fat-free mass index (FFMI).

RESULTS

During the follow-up of up to 18 years, 6061 deaths were identified. We observed J-shaped association of BMI (nadir at 22-26) and monotonically positive association of WC with all-cause, cardiovascular, and cancer mortality among Korean adults without a history of cancer or cardiovascular disease. In the BMI analysis, excluding ever smokers and adjusting for FFMI attenuated the excess mortality in underweight participants and transformed the J-shaped association into a monotonically positive shape, suggesting an increased mortality at BMI > 22.0. Excluding participants aged ≥ 70 years and deaths that occurred within 5 years of follow-up did not change the results. In the WC analysis, the monotonic positive associations did not change after the control. Similar results were observed among participants with a history of cancer or cardiovascular disease.

CONCLUSIONS

Our data suggest that both overall and abdominal body fat are associated with increased mortality in Korean adults.

[A Prognostic Model of Elderly Patients with Non-small Cell Lung Cancer Based on Geriatric Nutritional Risk Index]

BACKGROUND

The relationship between nutritional status and prognosis of cancer patients has emerged as a hotspot for research. The aim of this study is to explore the application value of the geriatric nutritional risk index (GNRI) in assessing the prognosis of elderly patients with non-small cell lung cancer (NSCLC), and establish a Nomogram to predict the prognosis of elderly patients with NSCLC.

METHODS

The data of patients with NSCLC aged ≥65 years who were initially treated in the First Affiliated Hospital of Zhengzhou University from January 2016 to December 2019 were retrospectively analyzed. To determine the optimal cut-off value for GNRI, receiver operating characteristic (ROC) curve was constructed, and the patients were divided into high and low GNRI groups. Kaplan-Meier curve and Log-rank test were used to compare overall survival (OS) of the two groups. Univariate and multivariate Cox regression was used to analyze the risk factors for poor prognosis in elderly patients with NSCLC. Nomogram predicting survival in elderly patients with NSCLC was constructed and validated by using R software.

RESULTS

Statistically significant differences in age, gender, body mass index (BMI), histological type, albumin, treatment methods, neutrophil to lymphocyte ratio (NLR), prognostic nutritional index (PNI), systemic immune-inflammation index (SII) and cytokeratin 19 fragment (CYFRA21-1) were observed between the high and low GNRI groups (P<0.05). The Kaplan-Meier curve showed a shorter OS in the low-GNRI group. Multivariate Cox regression analysis showed that CYFRA21-1>3.3 ng/mL was an independent risk factor for the development of OS in patients with NSCLC, and GNRI>97.09 was a protective factor [hazard ratio (HR)=0.52, 95% confidence interval (CI): 0.34-0.79, P<0.05]. Patients in the stage IV had a 1.98-fold increased risk of death compared with patients in the stage I (95%CI: 1.02-3.86, P<0.05). The risk of death was 3.58 times higher in patients receiving chemotherapy alone compared with those receiving combination therapy (95%CI: 2.03-6.32, P<0.05). A Nomogram constructed on the basis of GNRI, which predicted the OS of elderly patients with NSCLC with a concordance index (C-index) of 0.70 (95%CI: 0.65-0.76), and the area under the curve (AUC) for 1 and 2-year survival rates to be 0.93 (95%CI: 0.87-0.98) and 0.72 (95%CI: 0.63-0.80), respectively, and the calibration curve has a good coincidence of prediction.

CONCLUSIONS

High GNRI scores are significantly associated with improved survival in elderly patients with NSCLC, and reliance on cut-off values may provide the appropriate timing for nutritional support. The Nomogram constructed in this study can be used as an effective tool to predict the survival rate of elderly patients with NSCLC, which has strong clinical practicability.

Leptin: A Heavyweight Player in Obesity-Related Cancers

Obesity, defined as the abnormal or excessive expansion of white adipose tissue, has reached pandemic proportions and is recognized as an important health concern since it is a common root for several comorbidities, including malignancies. Indeed, the current knowledge of the white adipose tissue, which shifts its role from an energy storage tissue to an important endocrine and metabolic organ, has opened up new avenues for the discovery of obesity's effects on tumor biology. In this review, we will report the epidemiological studies concerning the strong impact of obesity in several types of cancer and describe the mechanisms underlying the heterotypic signals between cancer cell lines and adipocytes, with particular emphasis on inflammation, the insulin/IGF-1 axis, and adipokines. Among the adipokines, we will further describe the in vitro, in vivo, and clinical data concerning the role of leptin, recognized as one of the most important mediators of obesity-associated cancers. In fact, leptin physiologically regulates energy metabolism, appetite, and reproduction, and several studies have also described the role of leptin in affecting cancer development and progression. Finally, we will summarize the newest pharmacological strategies aimed at mitigating the protumorigenic effects of leptin, underlining their mechanisms of action.

Body Mass Index and Cancer Risk: An Umbrella Review of Meta-Analyses of Observational Studies

Increasing evidence indicates that obesity is a risk factor for various tumors. We aimed to clarify the evidence for an association between body mass index (BMI) and cancer risk based on existing systematic reviews and meta-analyses. Eighteen studies were included in this umbrella review after searching PubMed, Embase and Web of science. The results revealed that underweight was inversely associated with the incidence of brain tumors and positively related to the risk of esophageal and lung cancer. Overweight enhances the incidence of brain tumors, kidney cancer, endometrial cancer, ovarian cancer, multiple myeloma, bladder cancer and liver cancer. Obesity was related to the increased incidence of brain tumors, cervical cancer, kidney cancer, endometrial cancer, esophageal cancer, gastric cancer, ovarian cancer, multiple myeloma, gallbladder cancer, bladder cancer, colorectal cancer, liver cancer, thyroid cancer and Hodgkin's lymphoma. Moreover, dose-response analysis was conducted by 10 studies, and the results demonstrated that each 5 Kg/m² increase in BMI was associated with a 1.01- to 1.13-fold increased risk of general brain tumors, multiple myeloma, bladder cancer, pancreatic cancer, breast cancer, and non-Hodgkin's lymphoma. Every 1 Kg/m² increase in BMI was linked to 6% and 4% increases in the risk of kidney cancer and gallbladder cancer, respectively.

Racial difference in BMI and lung cancer diagnosis: analysis of the National Lung Screening Trial

Background

The inverse relationship between BMI and lung cancer diagnosis is well defined. However, few studies have examined the racial differences in these relationships. The purpose of this paper is to explore the relationships amongst race, BMI, and lung cancer diagnosis using the National Lung Screening Trial (NLST) data.

Methods

Multivariate regression analysis was used to analyze the BMI, race, and lung cancer diagnosis relationships.

Results

Among 53,452 participants in the NLST cohort, 3.9% were diagnosed with lung cancer, 43% were overweight, and 28% were obese. BMI was inversely related to lung cancer diagnosis among Whites: those overweight (aOR = .83, 95%CI = .75-.93), obese (aOR = .64, 95%CI = .56-.73) were less likely to develop lung cancer, compared to those with normal weight. These relationships were not found among African-Americans.

Conclusion

Our findings indicate that the inverse relationship of BMI and lung cancer risk among Whites is consistent, whereas this relationship is not significant for African-Americans. In consideration of higher lung cancer incidence among African Americans, we need to explore other unknown mechanisms explaining this racial difference.

Associations of genetic risk, BMI trajectories, and the risk of non-small cell lung cancer: a population-based cohort study

BACKGROUND

Body mass index (BMI) has been found to be associated with a decreased risk of non-small cell lung cancer (NSCLC); however, the effect of BMI trajectories and potential interactions with genetic variants on NSCLC risk remain unknown.

METHODS

Cox proportional hazards regression model was applied to assess the association between BMI trajectory and NSCLC risk in a cohort of 138,110 participants from the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. One-sample Mendelian randomization (MR) analysis was further used to access the causality between BMI trajectories and NSCLC risk. Additionally, polygenic risk score (PRS) and genome-wide interaction analysis (GWIA) were used to evaluate the multiplicative interaction between BMI trajectories and genetic variants in NSCLC risk.

RESULTS

Compared with individuals maintaining a stable normal BMI (n = 47,982, 34.74%), BMI trajectories from normal to overweight (n = 64,498, 46.70%), from normal to obese (n = 21,259, 15.39%), and from overweight to obese (n = 4,371, 3.16%) were associated with a decreased risk of NSCLC (hazard ratio [HR] for trend = 0.78, P < 2×10-16). An MR study using BMI trajectory associated with genetic variants revealed no significant association between BMI trajectories and NSCLC risk. Further analysis of PRS showed that a higher GWAS-identified PRS (PRSGWAS) was associated with an increased risk of NSCLC, while the interaction between BMI trajectories and PRSGWAS with the NSCLC risk was not significant (PsPRS= 0.863 and PwPRS= 0.704). In GWIA analysis, four independent susceptibility loci (P < 1×10-6) were found to be associated with BMI trajectories on NSCLC risk, including rs79297227 (12q14.1, located in SLC16A7, Pinteraction = 1.01×10-7), rs2336652 (3p22.3, near CLASP2, Pinteraction = 3.92×10-7), rs16018 (19p13.2, in CACNA1A, Pinteraction = 3.92×10-7), and rs4726760 (7q34, near BRAF, Pinteraction = 9.19×10-7). Functional annotation demonstrated that these loci may be involved in the development of NSCLC by regulating cell growth, differentiation, and inflammation.

CONCLUSIONS

Our study has shown an association between BMI trajectories, genetic factors, and NSCLC risk. Interestingly, four novel genetic loci were identified to interact with BMI trajectories on NSCLC risk, providing more support for the aetiology research of NSCLC.

TRIAL REGISTRATION

http://www.

CLINICALTRIALS

gov , NCT01696968 .

The Role of Mendelian Randomization Studies in Deciphering the Effect of Obesity on Cancer

Associations of obesity have been established for at least 11 cancer sites in observational studies, though some questions remain as to causality, strength of associations, and timing of associations throughout the life course. In recent years, Mendelian randomization (MR) has provided complementary information to traditional approaches, but the validity requires that the genetic instrumental variables be causally related to cancers only mediated by the exposure. We summarize and evaluate existing evidence from MR studies in comparison with conventional observational studies to provide insights into the complex relationship between obesity and multiple cancers. MR studies further establish the causality of adult obesity with esophageal adenocarcinoma and cancers of the colorectum, endometrium, ovary, kidney, and pancreas, as well as the inverse association of early life obesity with breast cancer. MR studies, which might account for lifelong adiposity, suggest that the associations in observational studies typically based on single measurement may underestimate the magnitude of the association. For lung cancer, MR studies find a positive association with obesity, supporting that the inverse association observed in some conventional observational studies likely reflects reverse causality (loss of lean body mass before diagnosis) and confounding by smoking. However, MR studies have not had sufficient power for gallbladder cancer, gastric cardia cancer, and multiple myeloma. In addition, more MR studies are needed to explore the effect of obesity at different timepoints on postmenopausal breast cancer and aggressive prostate cancer.

BMI changes and the risk of lung cancer in male never-smokers: A prospective cohort study

BACKGROUND

To investigate the association between the risk of lung cancer and short-term body mass index (BMI) changes in male never-smokers of a large population-based prospective study.

METHODS

A total of 37,085 male never-smokers from Kailuan cohort with at least ≥2 BMI measurements were recruited in the present study. The BMI change in the follow-up was calculated as the annual percent change between BMI at last examination and that at baseline, and categorized into five groups: stable (-0.1 to <0.1 kg/m2 /year), minor loss (-1.0 to <0.1 kg/m2 /year) or gain (0.1 to <1.0 kg/m2 /year), and major loss (<-1.0 kg/m2 /year) or gain (≥1.0 kg/m2 /year). The hazards ratios (HRs) and its 95% confidence intervals (CI) were estimated using Cox regression models.

RESULTS

During a median follow-up of 5.16 years, 224 lung cancer cases were identified. We found a U-shaped association between BMI changes and lung cancer risk. Compared to men with stable BMI, those with major loss had a nearly twofold higher risk of lung cancer (HR = 1.97, 95% CI: 1.12-3.45), as well as those with major gain had more than twofold higher risk of lung cancer (HR = 2.15, 95% CI: 1.15-4.02). The associations existed when the analysis was stratified by BMI, waist circumference and blood lipids, and lipoproteins concentration at baseline examination.

CONCLUSIONS

The dramatic changes in BMI, both gain and loss, might increase lung cancer risk. The control of body weight would be a potential way for lung cancer prevention especially for the nonsmokers.

Incidence trends and risk factors of lung cancer in never smokers: Pooled analyses of seven cohorts

The trends in incidence of lung cancer in never smokers are unclear as well as the significance of risk factors. We studied time trends in the incidence and risk factors of lung cancer in never smokers in Finland in a large, pooled cohort. We pooled data from seven Finnish health cohorts from the period between 1972 and 2015 with 106 193 never smokers. The harmonised risk factors included education, alcohol consumption, physical activity, height and BMI. We retrieved incident lung cancers from the nation-wide Finnish Cancer Registry. We estimated average annual percent change (AAPC) and the effects of risk factors on cause-specific hazard ratios (HRs) of lung cancer using Poisson regression. We detected 47 lung cancers in never smoking men (n = 31 859) and 155 in never smoking women (n = 74 334). The AAPC of lung cancer incidence was -3.30% (95% confidence interval [CI]: -5.68% to -0.88%, P = .009) in never smoking men and 0.00% (95% CI: -1.57% to 1.60%, P = .996) in never smoking women. Of the five studied risk factors only greater height in women had a statistically significant increased risk of lung cancer (multivariate HR = 1.84, 95%CI: 1.08 to 3.12). It is plausible that tobacco control measures focused on working places have reduced passive smoking among men more than among women, which could explain the declining trend in lung cancer incidence in never smoker men but not in never smoker women. As tobacco control measures have not been targeted to domestic environments, it is likely that women's exposure to passive smoking has continued longer.

Individual 5-Year Lung Cancer Risk Prediction Model in Korea Using a Nationwide Representative Database

Early detection of lung cancer by screening has contributed to reduce lung cancer mortality. Identifying high risk subjects for lung cancer is necessary to maximize the benefits and minimize the harms followed by lung cancer screening. In the present study, individual lung cancer risk in Korea was presented using a risk prediction model. Participants who completed health examinations in 2009 based on the Korean National Health Insurance (KNHI) database (DB) were eligible for the present study. Risk scores were assigned based on the adjusted hazard ratio (HR), and the standardized points for each risk factor were calculated to be proportional to the b coefficients. Model discrimination was assessed using the concordance statistic (c-statistic), and calibration ability assessed by plotting the mean predicted probability against the mean observed probability of lung cancer. Among candidate predictors, age, sex, smoking intensity, body mass index (BMI), presence of chronic obstructive pulmonary disease (COPD), pulmonary tuberculosis (TB), and type 2 diabetes mellitus (DM) were finally included. Our risk prediction model showed good discrimination (c-statistic, 0.810; 95% CI: 0.801-0.819). The relationship between model-predicted and actual lung cancer development correlated well in the calibration plot. When using easily accessible and modifiable risk factors, this model can help individuals make decisions regarding lung cancer screening or lifestyle modification, including smoking cessation.

Body Mass Index, Height, Weight Change, and Subsequent Lung Cancer Risk: The Japan Public Health Center-Based Prospective Study

BACKGROUND

Body mass index (BMI) is inversely associated with lung cancer risk, while residual confounding by smoking or weight change is controversial. Evidence on height and lung cancer is scarce.

METHODS

We investigated the associations between anthropometrics, BMI, and height, and incidence of lung cancer among 92,098 study subjects (44,158 men and 47,940 women) in the Japan Public Health Center-based Prospective Study. Cox proportional hazards regression was performed with adjustment for potential confounders and by cancer subtypes and smoking status. Information on weight and height was self-reported at baseline, and validated using measured health check-up data.

RESULTS

During follow-up between 1990 and 2013 (average, 19.1 years), a total of 2,152 lung cancer cases were newly diagnosed. In a multivariate regression model, lower BMI was positively associated with overall lung cancer risk [<19 kg/m² HR = 1.48; 95% confidence interval (CI) = 1.18-1.85 and 19-22.9 kg/m²; HR = 1.19; 95% CI = 1.05-1.35; P _trend = <0.001] in men. The risk estimate was also elevated for adenocarcinoma in the BMI <19 kg/m² category and for squamous cell carcinoma among men in the 19-22.9 kg/m² BMI category. An association was also observed between low BMI, weight decrease, and squamous cell carcinoma in women. No significant associations were observed for other weight categories, height, weight change and lung cancer, adenocarcinoma, squamous and small cell carcinoma.

CONCLUSIONS

Our prospective study suggests that lower BMI may be associated with an increased risk of smoking-related lung cancer in Japan, irrespective of gender.

IMPACT

This study highlights the association between lower BMI and the risk of lung cancer in men.

The Inverse Association of Body Mass Index with Lung Cancer: Exploring Residual Confounding, Metabolic Aberrations and Within-Person Variability in Smoking

BACKGROUND

The inverse observational association between body mass index (BMI) and lung cancer risk remains unclear. We assessed whether the association is explained by metabolic aberrations, residual confounding, and within-person variability in smoking, and compared against other smoking-related cancers.

METHODS

We investigated the association between BMI, and its combination with a metabolic score (MS) of mid-blood pressure, glucose, and triglycerides, with lung cancer and other smoking-related cancers in 778,828 individuals. We used Cox regression, adjusted and corrected for within-person variability in smoking (status/pack-years), calculated from 600,201 measurements in 221,958 participants.

RESULTS

Over a median follow-up of 20 years, 20,242 smoking-related cancers (6,735 lung cancers) were recorded. Despite adjustment and correction for substantial within-person variability in smoking, BMI remained inversely associated with lung cancer [HR per standard deviation increase, 0.87 (95% confidence interval 0.85-0.89)]. Individuals with BMI less than 25 kg/m² and high MS had the highest risk [HR 1.52 (1.44-1.60) vs. BMI ≥25 with low MS]. These associations were weaker and nonsignificant among nonsmokers. Similar associations were observed for head and neck cancers and esophageal squamous cell carcinoma, whereas for other smoking-related cancers, we generally observed positive associations with BMI.

CONCLUSIONS

The increased lung cancer risk with low BMI and high MS is unlikely due to residual confounding and within-person variability in smoking. However, similar results for other cancers strongly related to smoking suggest a remaining, unknown, effect of smoking.

IMPACT

Extensive smoking-adjustments may not capture all the effects of smoking on the relationship between obesity-related factors and risk of smoking-related cancers.

The Role of Nutritional Support in Malnourished Patients With Lung Cancer

This review aimed to aggregate and describe the available data about clinical nutrition in lung cancer and the role of the dietitian in multidisciplinary patient care. Scientific literature was searched in order to summarize key aspects related to clinical nutrition in lung cancer. This information can be used to arrange a proper nutritional therapy that can enhance patient treatment responses, prevent side-effects, shorten recovery time, improve prognosis and increase quality of life. An anti-inflammatory diet rich in antioxidants, immunomodulatory compounds, dietary fibre and an appropriate intake of protein can reduce the risk of initiation and progression of lung cancer, support the regeneration of tissues (also after surgery) and improve the nutritional status during the disease and after remission. A correct intake of nutrients is significant prior to disease occurrence and at every stage of treatment and recovery.

Tobacco Smoking and Risk of Second Primary Lung Cancer

INTRODUCTION

Lung cancer survivors are at high risk of developing a second primary lung cancer (SPLC). However, SPLC risk factors have not been established and the impact of tobacco smoking remains controversial. We examined the risk factors for SPLC across multiple epidemiologic cohorts and evaluated the impact of smoking cessation on reducing SPLC risk.

METHODS

We analyzed data from 7059 participants in the Multiethnic Cohort (MEC) diagnosed with an initial primary lung cancer (IPLC) between 1993 and 2017. Cause-specific proportional hazards models estimated SPLC risk. We conducted validation studies using the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (N = 3423 IPLC cases) and European Prospective Investigation into Cancer and Nutrition (N = 4731 IPLC cases) cohorts and pooled the SPLC risk estimates using random effects meta-analysis.

RESULTS

Overall, 163 MEC cases (2.3%) developed SPLC. Smoking pack-years (hazard ratio [HR] = 1.18 per 10 pack-years, p < 0.001) and smoking intensity (HR = 1.30 per 10 cigarettes per day, p < 0.001) were significantly associated with increased SPLC risk. Individuals who met the 2013 U.S. Preventive Services Task Force's screening criteria at IPLC diagnosis also had an increased SPLC risk (HR = 1.92; p < 0.001). Validation studies with the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial and European Prospective Investigation into Cancer and Nutrition revealed consistent results. Meta-analysis yielded pooled HRs of 1.16 per 10 pack-years (pmeta < 0.001), 1.25 per 10 cigarettes per day (pmeta < 0.001), and 1.99 (pmeta < 0.001) for meeting the U.S. Preventive Services Task Force's criteria. In MEC, smoking cessation after IPLC diagnosis was associated with an 83% reduction in SPLC risk (HR = 0.17; p < 0.001).

CONCLUSIONS

Tobacco smoking is a risk factor for SPLC. Smoking cessation may reduce the risk of SPLC. Additional strategies for SPLC surveillance and screening are warranted.

Impact of body mass index on survival and serious adverse events in advanced non-small cell lung cancer treated with bevacizumab: a meta-analysis of randomized clinical trials

PURPOSE

Lung cancer accounts for 28% of all cancer deaths, more deaths than any other cancer in the United States. The influence of body composition has been evaluated in several studies, specifically, the influence of obesity on lung cancer survival. Outcomes have been mixed, with some studies demonstrating a paradoxical beneficial effect in early lung cancer where survival is improved in obese patients. The study aim was to evaluate the impact of obesity on overall survival (OS), progression free survival (PFS), and occurrence of serious adverse events (SAE) in clinical trials evaluating bevacizumab for advanced non-small cell lung cancer (NSCLC).

METHODS

We performed a post hoc analysis combining available individual level data from bevacizumab randomized clinical trials available through the Clinical Study Data Request database. The primary outcome measured in our analysis was the influence of bevacizumab on OS stratified by body mass index (BMI). In addition to OS, both PFS and the occurrence of SAE requiring therapy interruption were evaluated. All endpoints were evaluated in patients who were obese (BMI ≥30.0 kg/m²) compared with non-obese (BMI <30.0 kg/m²). As a sensitivity analysis, endpoints were also evaluated in patients who were overweight (BMI ≥25.0 kg/m²) compared with non-overweight (BMI <25.0 kg/m²). In addition to analysis of each individual study, a meta-analysis was performed in order to calculate pooled hazard ratios (HR). Hazard ratios for both OS and PFS were calculated using multivariable Cox proportional hazards models. Odds ratios for SAE were calculated using multivariable logistic regression. The validity of the regression models was tested using a log-log plot and overall fit using the goodness of fit test.

RESULTS

After adjusting for covariates using a Cox proportional hazards model and combining the resulting adjusted hazard ratios using meta-analysis, there was no significant difference between obese and non-obese groups for OS or PFS. In addition, when treatment discontinuation due to an adverse event was assessed, none of the trials showed a significant difference between the obese and non-obese groups.

CONCLUSION

In this analysis of clinical trial data, obesity was not associated with worse survival versus non-obese individuals in advanced NSCLC. In addition, serious adverse events were similar between patients with and without obesity.

Causal relationships between body mass index, smoking and lung cancer: Univariable and multivariable Mendelian randomization

At the time of cancer diagnosis, body mass index (BMI) is inversely correlated with lung cancer risk, which may reflect reverse causality and confounding due to smoking behavior. We used two-sample univariable and multivariable Mendelian randomization (MR) to estimate causal relationships of BMI and smoking behaviors on lung cancer and histological subtypes based on an aggregated genome-wide association studies (GWASs) analysis of lung cancer in 29 266 cases and 56 450 controls. We observed a positive causal effect for high BMI on occurrence of small-cell lung cancer (odds ratio (OR) = 1.60, 95% confidence interval (CI) = 1.24-2.06, P = 2.70 × 10-4 ). After adjustment of smoking behaviors using multivariable Mendelian randomization (MVMR), a direct causal effect on small cell lung cancer (ORMVMR = 1.28, 95% CI = 1.06-1.55, PMVMR = .011), and an inverse effect on lung adenocarcinoma (ORMVMR = 0.86, 95% CI = 0.77-0.96, PMVMR = .008) were observed. A weak increased risk of lung squamous cell carcinoma was observed for higher BMI in univariable Mendelian randomization (UVMR) analysis (ORUVMR = 1.19, 95% CI = 1.01-1.40, PUVMR = .036), but this effect disappeared after adjustment of smoking (ORMVMR = 1.02, 95% CI = 0.90-1.16, PMVMR = .746). These results highlight the histology-specific impact of BMI on lung carcinogenesis and imply mediator role of smoking behaviors in the association between BMI and lung cancer.

High-Fat Diet-Related Obesity Promotes Urethane-Induced Lung Tumorigenesis in C57BL/6J Mice

Epidemiological studies have recently shown that obesity increases lung cancer risk, but the underlying biological connection is unclear. To determine whether high-fat diet (HFD)-induced obesity influences the susceptibility to chemical-induced lung tumorigenesis, a HFD feeding condition was combined with a multi-dose urethane-induced lung tumorigenesis model using C57BL/6J mice. In cell culture models, lung cancer cell lines A549 and H460 were used to investigate the effect of leptin on cell viability and its underlying mechanism of action. The results showed that obesity was induced with a 60 kcal% HFD feeding. Serum leptin levels increased with HFD feeding and further increased in urethane-administered and HFD-fed mice. Compared to the control diet-fed mice, the HFD-fed mice exhibited increased lung tumor burden and typical pro-tumorigenic STAT3 pathway activation in lung tissues after urethane administration. In vitro, leptin significantly increased the viability of lung cancer cell lines A549 and H460 in a dose-dependent manner by activation of STAT3, Bcl-2, and cyclin D1. These effects were significantly attenuated when PI3K or mTOR were inhibited by LY294002 or rapamycin, respectively. These results suggested that HFD-induced obesity could promote the development of lung tumorigenesis in C57BL/6J mice, and leptin-mediated activation of the PI3K/Akt/mTOR/STAT3 pathway was likely involved in this mechanism.

Body mass index and waist circumference in relation to the risk of 26 types of cancer: a prospective cohort study of 3.5 million adults in Spain

BACKGROUND

A high body mass index (BMI) has been associated with increased risk of several cancers; however, whether BMI is related to a larger number of cancers than currently recognized is unclear. Moreover, whether waist circumference (WC) is more strongly associated with specific cancers than BMI is not well established. We aimed to investigate the associations between BMI and 26 cancers accounting for non-linearity and residual confounding by smoking status as well as to compare cancer risk estimates between BMI and WC.

METHODS

Prospective cohort study with population-based electronic health records from Catalonia, Spain. We included 3,658,417 adults aged ≥ 18 years and free of cancer at baseline between 2006 and 2017. Our main outcome measures were cause-specific hazard ratios (HRs) with 99% confidence intervals (CIs) for incident cancer at 26 anatomical sites.

RESULTS

After a median follow-up time of 8.3 years, 202,837 participants were diagnosed with cancer. A higher BMI was positively associated with risk of nine cancers (corpus uteri, kidney, gallbladder, thyroid, colorectal, breast post-menopausal, multiple myeloma, leukemia, non-Hodgkin lymphoma) and was positively associated with three additional cancers among never smokers (head and neck, brain and central nervous system, Hodgkin lymphoma). The respective HRs (per 5 kg/m2 increment) ranged from 1.04 (99%CI 1.01 to 1.08) for non-Hodgkin lymphoma to 1.49 (1.45 to 1.53) for corpus uteri cancer. While BMI was negatively associated to five cancer types in the linear analyses of the overall population, accounting for non-linearity revealed that BMI was associated to prostate cancer in a U-shaped manner and to head and neck, esophagus, larynx, and trachea, bronchus and lung cancers in an L-shaped fashion, suggesting that low BMIs are an approximation of heavy smoking. Of the 291,305 participants with a WC measurement, 27,837 were diagnosed with cancer. The 99%CIs of the BMI and WC point estimates (per 1 standard deviation increment) overlapped for all cancers.

CONCLUSIONS

In this large Southern European study, a higher BMI was associated with increased risk of twelve cancers, including four hematological and head and neck (only among never smokers) cancers. Furthermore, BMI and WC showed comparable estimates of cancer risk associated with adiposity.

The Obesity Paradox in Lung Cancer: Associations With Body Size Versus Body Shape

Background

The association between obesity and lung cancer (LC) remains poorly understood. However, other indices of obesity on the basis of body shape instead of body size have not been examined yet. The aim of this study was to evaluate the association between different indices of body size and body shape and the risk of LC. In particular, this study examined the association between A Body Shape Index, a more precise indicator of abdominal fat than traditional anthropometric measures, and the risk of LC.

Methods

In the prospective cohort the Rotterdam Study, we analysed data of 9,689 participants. LC diagnoses were based on medical records and anthropometric measurements were assessed at baseline. Cox-regression analyses with corresponding Hazard Ratios were used to examine the association between the anthropometric measurements and the risk of LC with adjustment for potential confounders. Potential non-linear associations were explored with cubic splines using the Likelihood ratio (LR) test.

Results

During follow-up, 319 participants developed LC. Body mass Index (BMI) was inversely associated with the risk of lung cancer (HR 0.94, 95% CI: 0.91–0.97) and persisted after excluding lung cancer cases during the first 10 years of follow-up. There was evidence for a non-linear association between BMI and the risk of lung cancer (0,04, df = 1), which indicated that the inverse association between BMI and lung cancer was mainly present in non-obese participants. Waist circumference (WC) (HR 1.03 95% CI: 1.01–1.05), Waist-to-Hip Ratio (WHR) (HR 1.23 95% CI: 1.09–1.38) and ABSI (A Body Shape Index) (HR 1.17 95% CI: 1.05–1.30) were positively and linearly associated with the risk of lung cancer.

Conclusions

Body shape rather than body size may be an important risk indicator of LC. Future research should focus on the role of visceral fat and the risk of LC as well as the underlying mechanisms.

Statistical Assessment of Toxic and Essential Metals in the Serum of Female Patients with Lung Carcinoma from Pakistan

Lung cancer (LC) is the number one cancer killer of women both in the USA and around the world. Besides cigarette smoking, an important feature in the etiology of LC is its strong association with exposure of toxic metals. The primary objective of the present investigation was to assess the concentrations of toxic/essential elements (Ni, Ca, Se, Zn, Co, K, Cr, As, Cu, Na, Fe, Hg, Cd, Mg, Mn, and Pb) in the serum samples of LC female patients with female controls by atomic absorption spectrometry after wet-acid digestion procedure. Carcinoembryonic antigen (CEA) was also measured in the serum of the patients using immunoradiometric method. Comparative appraisal of the data revealed that concentrations of Cr, Mg, Cd, Pb, Hg, As, and Ni were noted to be high significantly in serum of LC female patients, while the average Fe, Co, Mn, Na, K, Zn, Ca, and Se were observed at higher levels in female controls (p < 0.05). The correlation study revealed significantly different mutual associations among the elements in the both donor groups. Markedly, variations in the elemental levels were also noted for different types (non-small cell lung cancer and small cell lung cancer) and stages (I, II, III, & IV) of LC patients. Multivariate analyses showed substantially diverse apportionment of the metals in the female patients and female controls. Hence, present findings suggest that the toxic and essential metals accumulated in the body may pose a high risk for LC progression in Pakistani females.

Quantitative Pectoralis Muscle Area is Associated with the Development of Lung Cancer in a Large Lung Cancer Screening Cohort

BACKGROUND

Studies have demonstrated an inverse relationship between body mass index (BMI) and the risk of developing lung cancer. We conducted a retrospective cohort study evaluating baseline quantitative computed tomography (CT) measurements of body composition, specifically muscle and fat area in a large CT lung screening cohort (CTLS). We hypothesized that quantitative measurements of baseline body composition may aid in risk stratification for lung cancer.

METHODS

Patients who underwent baseline CTLS between January 1st, 2012 and September 30th, 2014 and who had an in-network primary care physician were included. All patients met NCCN Guidelines eligibility criteria for CTLS. Quantitative measurements of pectoralis muscle area (PMA) and subcutaneous fat area (SFA) were performed on a single axial slice of the CT above the aortic arch with the Chest Imaging Platform Workstation software. Cox multivariable proportional hazards model for cancer was adjusted for variables with a univariate p < 0.2. Data were dichotomized by sex and then combined to account for baseline differences between sexes.

RESULTS

One thousand six hundred and ninety six patients were included in this study. A total of 79 (4.7%) patients developed lung cancer. There was an association between the 25th percentile of PMA and the development of lung cancer [HR 1.71 (1.07, 2.75), p < 0.025] after adjusting for age, BMI, qualitative emphysema, qualitative coronary artery calcification, and baseline Lung-RADS® score.

CONCLUSIONS

Quantitative assessment of PMA on baseline CTLS was associated with the development of lung cancer. Quantitative PMA has the potential to be incorporated as a variable in future lung cancer risk models.

Risk factors for primary lung cancer among never-smoking women in South Korea: a retrospective nationwide population-based cohort study

BACKGROUND/AIMS

We performed a large-scale, retrospective, nationwide, cohort study to investigate the risk factors for lung cancer among never-smoking Korean females.

METHODS

The study data were collected from a general health examination and questionnaire survey of eligible populations conducted between January 1, 2003 and December 31, 2004; the data were acquired from the tailored big data distribution service of the National Health Insurance Service. After a 1-year clearance period, 5,860,922 of 6,318,878 never-smoking female participants with no previous history of lung cancer were investigated. After a median follow-up of 11.4 years, 43,473 (0.74%) participants were defined as "newly diagnosed lung cancer".

RESULTS

After adjusting for all variables at baseline, the variables older age, lower body mass index (BMI), less exercise, frequent alcohol drinking, meat-based diet, rural residence, and previous history of cancer were associated with a higher incidence of lung cancer. Low BMI (< 18.5 kg/m2: hazard ratio [HR], 1.33; 95% confidence interval [CI], 1.27 to 1.40) was a significant independent risk factor; as BMI decreased, HR increased. Negative associations between BMI and lung-cancer development were also observed after controlling for age (p for trend < 0.001). Drinking alcohol one to two times a week (HR, 1.25; 95% CI, 1.21 to 1.28) and eating a meat-based diet (HR, 1.08; 95% CI, 1.01 to 1.15) were associated with lung-cancer incidence.

CONCLUSION

Modifiable baseline characteristics, such as BMI, exercise, alcohol consumption, and diet, are risk factors for lung-cancer development among never- smoking females. Thus, lifestyle modifications may help prevent lung cancer.

The relation between healthy lifestyle changes and decrease in systemic inflammation in patients with stable cardiovascular disease

BACKGROUND AND AIMS

Pharmacological lowering of inflammation has proven effective in reducing recurrent cardiovascular event rates. Aim of the current study is to evaluate lifestyle changes (smoking cessation, weight loss, physical activity level increase, alcohol moderation, and a summary lifestyle improvement score) in relation to change in plasma C-reactive protein (CRP) concentration in patients with established cardiovascular disease.

METHODS

In total, 1794 patients from the UCC-SMART cohort with stable cardiovascular disease and CRP levels ≤10 mg/L, who returned for a follow-up study visit after median 9.9 years (IQR 5.4-10.8), were included. The relation between changes in smoking status, weight, physical activity, alcohol consumption, a summary lifestyle improvement score and change in plasma CRP concentration was evaluated with linear regression analyses.

RESULTS

Smoking cessation was related to a 0.40 mg/L decline in CRP concentration (β-coefficient -0.40; 95%CI -0.73,-0.07). Weight loss (per 1SD = 6.4 kg) and increase in physical activity (per 1 SD = 48 MET hours per week) were related to a decrease in CRP concentration (β-coefficients -0.25; 95%CI -0.33,-0.16 and -0.09; 95%CI -0.17,-0.01 per SD). Change in alcohol consumption was not related to CRP difference. Every point higher in the summary lifestyle improvement score was related to a decrease in CRP concentration of 0.17 mg/L (β-coefficient -0.17; 95%CI -0.26,-0.07).

CONCLUSIONS

Smoking cessation, increase in physical activity, and weight loss are related to a decrease in CRP concentration in patients with stable cardiovascular disease. Patients with the highest summary lifestyle improvement score have the most decrease in CRP concentration. These results may indicate that healthy lifestyle changes contribute to lowering systemic inflammation, potentially leading to a lower cardiovascular risk in patients with established cardiovascular disease.

Tea consumption and colorectal cancer risk: a meta-analysis of prospective cohort studies

PURPOSE

Data from in vitro and animal studies support the preventive effect of tea (Camellia sinensis) against colorectal cancer. Further, many epidemiologic studies evaluated the association between tea consumption and colorectal cancer risk, but the results were inconsistent. We conducted a meta-analysis of prospective cohort studies to systematically assess the association between tea consumption and colorectal cancer risk.

METHODS

A comprehensive literature review was conducted to identify the related articles by searching PubMed and Embase up to June, 2019. Summary relative risks (RRs) and 95% confidence intervals (CIs) were calculated using a fixed effect model.

RESULTS

Twenty cohort articles were included in the present meta-analysis involving 2,068,137 participants and 21,437 cases. The combined RR of colorectal cancer for the highest vs. lowest tea consumption was determined to 0.97 (95% CI 0.94-1.01) with marginal heterogeneity (I² = 24.0%, P = 0.093) among all studies. This indicated that tea consumption had no significant association with colorectal cancer risk. Stratified analysis showed that no significant differences were found in all subgroups. We further conducted the gender-specific meta-analysis for deriving a more precise estimation. No significant association was observed between tea consumption and colorectal cancer risk in male (combined RR = 0.97; 95% CI 0.90-1.04). However, tea consumption had a marginal significant inverse impact on colorectal cancer risk in female (combined RR = 0.93; 95% CI 0.86-1.00). Further, we found a stronger inverse association between tea consumption and risk of colorectal cancer among the female studies with no adjustment of coffee intake (RR: 0.90; 95% CI 0.82-1.00, P < 0.05) compared to the female studies that adjusted for coffee intake (RR = 0.97; 95% CI 0.87-1.09, P > 0.05).

CONCLUSIONS

Our finding indicates that tea consumption has no significant impact on the colorectal cancer risk in both genders combined, but gender-specific meta-analysis shows that tea consumption has a marginal significant inverse impact on colorectal cancer risk in female.

The Molecular Mechanism of Metabolic Remodeling in Lung Cancer

Metabolic remodeling is a key phenomenon in the occurrence and development of tumors. It not only offers materials and energy for the survival and proliferation of tumor cells, but also protects tumor cells so that they may survive, proliferate and transfer in the harsh microenvironment. This paper attempts to reveal the role of abnormal metabolism in the development of lung cancer by considering the processes of glycolysis and lipid metabolism, Identification of the molecules that are specifically used in the processes of glycolysis and lipid metabolism, and their underlying molecular mechanisms, is of great clinical and theoretical significance. We will focus on the recent progress in elucidating the molecular mechanism of metabolic remodeling in lung cancer.

Postoperative outcomes of robotic-assisted lobectomy in obese patients with non-small-cell lung cancer

OBJECTIVES

The aim of this study was to assess the postoperative outcomes of robotic-assisted lobectomy in obese patients to determine the impact of the robotic approach on a high-risk population who were candidates for major pulmonary resection for non-small-cell lung cancer (NSCLC).

METHODS

Between January 2007 and August 2018, we retrospectively reviewed the medical records of 224 obese patients (body mass index ≥ 30) who underwent pulmonary lobectomy at our institution via robotic-assisted thoracic surgery (RATS, n = 51) or lateral muscle-sparing thoracotomy (n = 173).

RESULTS

Forty-two patients were individually matched with those who had the same pathological tumour stage and similar comorbidities and presurgical treatment. The median operative time was significantly longer in the RATS group compared to that in the thoracotomy group (200 vs 158 min; P = 0.003), whereas the length of stay was significantly better for the RATS group (5 vs 6 days; P = 0.047). Postoperative complications were significantly more frequent after open lobectomy than in the RATS group (42.9% vs 16.7%; P = 0.027). After a median follow-up of 4.4 years, the 5-year overall survival rate was 67.6% [95% confidence interval (CI) 45.7–82.2] for the RATS group, and 66.1% (95% CI 46.8–79.9) for the open surgery group (log-rank P = 0.54). The 5-year cumulative incidence of cancer-related deaths was 24.8% (95% CI 9.7–43.5) for the RATS group and 23.6% (95% CI 10.8–39.2) for the open surgery group (Gray’s test, P = 0.69).

CONCLUSIONS

RATS is feasible and safe for obese patients with NSCLC with advantages compared to open surgery in terms of early postoperative outcomes. In addition, the long-term survival rate was comparable to that of the open approach.

Predicted lean body mass, fat mass and risk of lung cancer: prospective US cohort study

An inverse association between body mass index (BMI) and risk of lung cancer has been reported. However, the association of body composition such as fat mass (FM) and lean body mass (LBM) with risk of lung cancer has not been fully investigated. Using two large prospective cohort studies (Nurses' Health Study, 1986-2014; Health Professionals Follow-up Study, 1987-2012) in the United States, we included 100,985 participants who were followed for occurrence of lung cancer. Predicted FM and LBM derived from validated anthropometric prediction equations were categorized by sex-specific deciles. During an average 22.3-year follow-up, 2615 incident lung cancer cases were identified. BMI showed an inverse association with lung cancer risk. Participants in the 10th decile of predicted FM and LBM had a lower risk of lung cancer compared with those in the 1st decile, but when mutually adjusted for each other, predicted FM was not associated with lung cancer risk (adjusted hazard ratio [aHR] = 0.98, 95% confidence interval [CI] 0.72-1.35; P(trend) = 0.97) whereas predicted LBM had an inverse association (aHR = 0.73, 95% CI 0.53-1.00; P(trend) = 0.03), especially among participants who were current smokers or had smoked in the previous 10 years (aHR = 0.55, 95% CI 0.36-0.84; P(trend) = 0.008). In conclusion, BMI was inversely associated with lung cancer risk. Based on anthropometric prediction equations, low LBM rather than low FM accounted for the inverse association between BMI and lung cancer risk.

Perioperative Management May Improve Long-term Survival in Patients After Lung Cancer Surgery: A Retrospective Cohort Study

BACKGROUND:

Surgical resection is the main treatment for patients with non–small-cell lung cancer (NSCLC), but patients’ long-term outcome is still challenging. The purpose of this study was to identify predictors of long-term survival in patients after lung cancer surgery.

METHODS:

Patients who underwent surgery for NSCLC from January 1, 2006, to December 31, 2009, were enrolled into this retrospective cohort study. The primary outcome was the survival length after surgery. Predictors of long-term survival were screened with the multivariable Cox proportional hazard model.

RESULTS:

Postoperative follow-up was completed in 588 patients with a median follow-up duration of 5.2 years (interquartile range, 2.0–6.8). Two hundred ninety-one patients (49.5%) survived at the end of follow-up with median survival duration of 64.3 months (interquartile range, 28.5–81.6). The overall survival rates were 90.8%, 70.0%, and 57.1% at the end of the first, third, and fifth year after surgery, respectively. Limited resection (hazard ratio [HR], 1.46; 95% confidence interval [CI], 1.08–1.98; P = .013) and large tumor size (HR, 1.29; 95% CI, 1.17–1.42; P < .001) were associated with short survival; whereas high body mass index grade (HR, 0.82; 95% CI, 0.69–0.97; P = .021), highly differentiated tumor (HR, 0.59; 95% CI, 0.37–0.93; P = .024), dissection of mediastinal lymph node during surgery (HR, 0.45; 95% CI, 0.30–0.67; P < .001), and perioperative use of dexamethasone (HR, 0.70; 95% CI, 0.54–0.90; P = .006) were associated with long survival. No association was found between perioperative use of flurbiprofen axetil and long survival (HR, 0.80; 95% CI, 0.62–1.03; P = .086). However, combined administration of dexamethasone and flurbiprofen axetil was associated with longer survival (compared to no use of both: adjusted HR, 0.57; 95% CI, 0.38–0.84; P = .005).

CONCLUSIONS:

Certain factors in particular perioperative dexamethasone and flurbiprofen axetil therapy may improve patients’ long-term survival after surgery for NSCLC. Given the small sample size, these findings should be interpreted with caution, and randomized clinical trials are needed for further clarification.

Paradoxical relationship between body mass index and bone mineral density in patients with non-small cell lung cancer with brain metastasis

Background and purpose

Low body mass index (BMI) at presentation has been reported to be associated with higher incidence and mortality of lung cancer, but studies on the relationship between brain metastasis and BMI at presentation are lacking. This study aimed to evaluate the association between brain metastasis and BMI and bone mineral density (BMD) in NSCLC.

Methods

We retrospectively enrolled patients with non–small cell lung cancer who underwent brain magnetic resonance imaging with contrast within 3 months of diagnosis. The BMI was collected, and the BMD was measured in Hounsfield unit (HU) on initial staging computed tomography scans. The independent relationship between BMI and BMD was assessed using multivariable linear regression according to the presence of brain metastasis.

Results

A total of 356 consecutive NSCLC patients were enrolled in the study over a 8-year period in a single institution. Lower BMI with higher BMD was an independent predictive factor for brain metastasis in patients with NSCLC, relative to the other group (HR, 2.03; 95% CI, 1.21 to 3.40; P = 0.007). We also found a significant negative correlation between BMI and BMD among patients with NSCLC with brain metastases (B, -3.343; 95% confidence interval, -6.352 to -0.333; P = 0.030).

Conclusions

Brain metastasis may possibly be associated with lower BMI and higher BMD in NSCLC patients. We expect that these results may facilitate future predictions of brain metastases during the clinical course of NSCLC and enhance our understanding of the underlying mechanisms that link brain metastases and lung cancer.

Cancer risk in relation to body fat distribution, evaluated by DXA-scans, in postmenopausal women - the Prospective Epidemiological Risk Factor (PERF) study

Studies with direct measures of body fat distribution are required to explore the association between central and general obesity to cancer risk in postmenopausal women. This study investigates the association between central obesity and general obesity to overall/site-specific cancer risk in postmenopausal women. The analysis included 4,679 Danish postmenopausal women. Body fat distribution was evaluated by whole-body dual-energy X-ray absorptiometry scanners. Cancer diagnoses were extracted from the Danish Cancer Registry and multivariable Cox regression models explored the association between cancer risk and central obesity after adjusting for BMI. Our results showed that high central obese women had a 50% increased risk of overall cancer relative to low central obese women (Q1vs.Q4: [HR:1.50, CI:1.20-1.88]). For site-specific cancers, central obesity was significantly associated with Respiratory (Q1vs.Q4: [HR:2.01, CI:1.17-3.47]), Gastrointestinal (Q1vs.Q4: [HR:1.55, CI:0.99-2.41]) and Female genital organs (Q1vs.Q4: [HR:1.95, CI:1.00-3.78]) cancer diagnoses. Sub-analyses stratified by smoking-habits found a significant association between central obesity and a cancer diagnosis for current (Q1vs.Q4: [HR:1.93, CI:1.25-2.99]) and former smokers (Q1vs.Q4: [HR:1.90, CI:1.23-2.94]). These analyses suggest that central obesity is associated with some cancers in postmenopausal women independent of BMI.

Central body fatness is a stronger predictor of cancer risk than overall body size

The importance of body size versus weight distribution for cancer risk is unclear. We investigated associations between measures of body size and shape and the risk of developing cancer. The study population consisted of 26,607 participants from the Alberta’s Tomorrow Project cohort. Two main measures of body shape and size were examined: i) body mass index (BMI) and ii) waist circumference (WC). Incident cancers were identified via linkage to the Alberta Cancer Registry. Cox proportional hazards models were used. Males and females classified as obese (BMI ≥ 30 kg /m⁻²) have a 33% and 22% increased risk of all-cancer, respectively, than their normal weight counterparts. Similar all-cancer risk increases are observed for those above sex-specific WC guidelines. Mutual adjustment for WC attenuates the association between BMI and all-cancer risk, especially among females. Central adiposity appears to be a stronger predictor of all-cancer risk than body size.

Obesity is linked to increased cancer risk but the impact of body size versus weight distribution in determining the increased risk is unclear. Here the authors examined body mass index, waist circumference, and waist to hip ratio in relation to all-cancer incidence and incidence of seven individual cancers in a population of approximately 26,000 individual and conclude that central adiposity appears to be a stronger predictor of all-cancer risk than body size.

Overweight in midlife and risk of cancer in late life: A nationwide Swedish twin study

Our study examined whether midlife overweight (body mass index [BMI] ≥25) is associated with late-life cancer risk and explored the role of genetic and early-life environmental factors in this association. The study included 14,766 individuals from the Swedish Twin Registry, whose midlife (30-50 years) height and weight were recorded. Information on cancer diagnoses in late life (>65 years) was derived from the National Patient Registry and Cancer Registry. Generalized estimating equation (GEE) models were used to analyze unmatched case-control data (controlled for the clustering of twins within a pair). A co-twin matched case-control analysis used conditional logistic regression to compare cancer-discordant twins. Of all participants, 3968 (26.9%) were overweight and 4253 (28.8%) had cancer. In multi-adjusted GEE models using normal-weight (BMI 18.5-24.9) participants as the reference group, overweight was related to higher risk of colon cancer (OR 1.36, 95% CI: 1.00-1.84, p = 0.049), liver cancer (OR 2.00, 95% CI: 1.11-3.62), cervix uteri cancer (OR 2.86, 95% CI: 1.19-6.91) and corpus uteri cancer (OR 1.78, 95% CI: 1.14-2.78) but lower risk of nonmelanoma skin cancer (OR 0.77, 95% CI: 0.66-0.90). In conditional logistic regression analysis, these associations were attenuated becoming nonsignificance. The difference in ORs from the unmatched and matched analyses was not significant. In conclusion, midlife overweight is associated with increased risk of late-life colon, liver and uterine cancer but reduced risk of late-life nonmelanoma skin cancer. Further investigations are warranted to explore the role of genetic and early-life environmental factors in these associations.

A multi-parameterized artificial neural network for lung cancer risk prediction

The objective of this study is to train and validate a multi-parameterized artificial neural network (ANN) based on personal health information to predict lung cancer risk with high sensitivity and specificity. The 1997-2015 National Health Interview Survey adult data was used to train and validate our ANN, with inputs: gender, age, BMI, diabetes, smoking status, emphysema, asthma, race, Hispanic ethnicity, hypertension, heart diseases, vigorous exercise habits, and history of stroke. We identified 648 cancer and 488,418 non-cancer cases. For the training set the sensitivity was 79.8% (95% CI, 75.9%-83.6%), specificity was 79.9% (79.8%-80.1%), and AUC was 0.86 (0.85-0.88). For the validation set sensitivity was 75.3% (68.9%-81.6%), specificity was 80.6% (80.3%-80.8%), and AUC was 0.86 (0.84-0.89). Our results indicate that the use of an ANN based on personal health information gives high specificity and modest sensitivity for lung cancer detection, offering a cost-effective and non-invasive clinical tool for risk stratification.

Leitzmann M, Brenner*2 H, Mons*2 U. Cancers Due to Excess Weight, Low Physical Activity, and Unhealthy Diet

BACKGROUND

Excess weight, low physical activity, low intakes of dietary fiber, fruits, and vegetables, and high meat and salt intake increase cancer risk.

METHODS

Numbers and proportions (population-attributable fractions, PAF) of incident cancer cases in Germany in 2018 attributable to these factors were estimated by sex and age groups for ages 35 to 84 years using population projections, national cancer incidence and exposure data, and published risk estimates.

RESULTS

Estimated numbers (percentages) of attributable cancers were 30 567 (7%) for excess weight, 27 081 (6%) for low physical activity, 14 474 (3%) for low dietary fiber intake, 9447 (2%) for low fruit and vegetable consumption, 9454 (2%) and 1687 (0.4%) for processed meat and high red meat consumption, respectively, and 1204 (0.3%) for high salt intake. Excess weight substantially contributed to endometrial, renal, and liver cancer (PAF = 24 to 35%). Low physical activity contributed to endometrial, renal, and lung cancer (PAF = 15 to 19%), and dietary factors mainly contributed to colorectal, breast, and lung cancer (PAF = 9 to 16%).

CONCLUSION

A considerable proportion of cancer cases are attributable to excess weight, physical inactivity, and unhealthy dietary habits. Major prevention efforts are needed to reduce the cancer incidence attributable to these avoidable factors.

Body mass index and cancer risk among Chinese patients with type 2 diabetes mellitus

Background

Obesity and diabetes are two risk factors for cancer. To evaluate the association of body mass index (BMI) with cancer risk in diabetic patients may improve current understanding of potential mechanisms.

Methods

A retrospective cohort study was conducted in 51,004 newly diagnosed T2DM patients derived from an electronic health record (EHR) database of Minhang district in Shanghai, China. Incident cancer cases and all-cause deaths occurred before September 30, 2015 were identified by linking with the Shanghai Cancer Registry and the Shanghai Vital Statistics. To examine the potential non-linear and linear relationships of BMI and cancer risk, Cox proportional hazard models with and without restricted cubic spline functions were used, respectively.

Results

A non-linear association was observed between BMI and overall cancer incidence in men younger than 60 years old (p for non-linearity = 0.009). Compared with those having BMI of 25.0 kg/m², the cancer risk increased in those with either lower or higher BMI. In women older than 60 years old, linear dose-response relationships were observed between BMI and the risk of both overall cancer and breast cancer. As each unit increase in BMI, the overall cancer risks elevated by 3% (95%CI: 1–5%) and the breast cancer risks increased by 7% (95%CI: 1–13%). No significant association was observed between BMI and other common cancer sites.

Conclusions

Our results show that the effect of BMI on cancer risk in Chinese patients with T2DM may vary by gender, age and cancer subtypes, suggesting different underlying biological mechanisms.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4675-0) contains supplementary material, which is available to authorized users.

Main and interactive effects of physical activity, fitness and body mass in the prevention of cancer from the Copenhagen Male Study

Little knowledge exists about the role of cardiorespiratory fitness (CRF) or its interaction with excess adiposity determined by body mass index (BMI) in cancer prevention. A total of 5,128 middle-aged men, without a history of cancer at baseline in 1970–71, were examined for subsequent incidence and mortality of several cancer types. Participants’ data were linked with cancer registration and mortality data to March 2017. During 47 years of follow-up, a total of 1,920 incident cases and 1,638 cancer-related deaths were ascertained. BMI, particularly obesity, was associated with (i) incidence and (ii) mortality from respiratory/thoracic cancers; and (iii) all cancer-cause mortality. The respective adjusted hazard ratios (HRs) were: (i) 0.51 (95%CI:0.32–0.79), (ii) 0.48 (95%CI:0.30–0.75) and (iii) 0.73 (95%CI:0.59–0.89) when compared obese men (BMI ≥30 kg/m²) to men with healthy-BMI (<25 kg/m²). Increasing CRF was inversely associated with incidence and mortality of respiratory/thoracic cancers, HRs 0.78 (95%CI:0.67–0.90) and 0.73 (95%CI:0.63–0.84) respectively; and all cancer-cause incidence 0.92 (95%CI:0.86–0.98) and mortality 0.85 (95%CI:0.79–0.91). Physical activity (PA) was not associated with most outcomes. We found no evidence of interactions between CRF or PA and BMI on cancer risk. This evidence suggests that midlife CRF is associated with lowered risk of cancer incidence and mortality with no evidence of cancer risk modification by BMI.

Overall and Central Obesity and Risk of Lung Cancer: A Pooled Analysis

Background

The obesity-lung cancer association remains controversial. Concerns over confounding by smoking and reverse causation persist. The influence of obesity type and effect modifications by race/ethnicity and tumor histology are largely unexplored.

Methods

We examined associations of body mass index (BMI), waist circumference (WC), and waist-hip ratio (WHR) with lung cancer risk among 1.6 million Americans, Europeans, and Asians. Cox proportional hazard regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) with adjustment for potential confounders. Analyses for WC/WHR were further adjusted for BMI. The joint effect of BMI and WC/WHR was also evaluated.

Results

During an average 12-year follow-up, 23 732 incident lung cancer cases were identified. While BMI was generally associated with a decreased risk, WC and WHR were associated with increased risk after controlling for BMI. These associations were seen 10 years before diagnosis in smokers and never smokers, were strongest among blacks, and varied by histological type. After excluding the first five years of follow-up, hazard ratios per 5 kg/m2 increase in BMI were 0.95 (95% CI = 0.90 to 1.00), 0.92 (95% CI = 0.89 to 0.95), and 0.89 (95% CI = 0.86 to 0.91) in never, former, and current smokers, and 0.86 (95% CI = 0.84 to 0.89), 0.94 (95% CI = 0.90 to 0.99), and 1.09 (95% CI = 1.03 to 1.15) for adenocarcinoma, squamous cell, and small cell carcinoma, respectively. Hazard ratios per 10 cm increase in WC were 1.09 (95% CI = 1.00 to 1.18), 1.12 (95% CI = 1.07 to 1.17), and 1.11 (95% CI = 1.07 to 1.16) in never, former, and current smokers, and 1.06 (95% CI = 1.01 to 1.12), 1.20 (95% CI = 1.12 to 1.29), and 1.13 (95% CI = 1.04 to 1.23) for adenocarcinoma, squamous cell, and small cell carcinoma, respectively. Participants with BMIs of less than 25 kg/m2 but high WC had a 40% higher risk (HR = 1.40, 95% CI = 1.26 to 1.56) than those with BMIs of 25 kg/m2 or greater but normal/moderate WC.

Conclusions

The inverse BMI-lung cancer association is not entirely due to smoking and reverse causation. Central obesity, particularly concurrent with low BMI, may help identify high-risk populations for lung cancer.