Lung function impairment in the German Lung Cancer Screening Intervention Study (LUSI): prevalence, symptoms, and associations with lung cancer risk, tumor histology and all-cause mortality

Impaired lung function and lung cancer risk in 461 183 healthy individuals: a cohort study

BACKGROUND

It has been known that smoking and various lung diseases including lung cancer can cause lung function impairment. However, the impact of different types of lung function impairments, such as preserved ratio impaired spirometry (PRISm) and airflow obstruction (AO), on the incidence and mortality of lung cancer in both general and never-smoker populations remains unclear. We wished to examine the effect of lung function impairments on lung cancer risks.

METHODS

This was a retrospective cohort study (1 January 1994 to 31 December 2017) of individuals from a health surveillance programme in Taiwan who underwent baseline spirometry tests at the entry point. PRISm was defined as an FEV1/FVC (forced expiratory volume in 1 s/forced vital capacity) ratio >0.7 and FEV1 <0.8, while AO was defined as an FEV1/FVC ratio <0.7. Cox proportional hazards models and cubic spline curves were used to examine the associations between lung function impairments and lung cancer risks.

RESULTS

The study included 461,183 individuals, of whom 14.3% had PRISm and 7.9% had AO. A total of 4038 cases of lung cancer and 3314 lung cancer-related deaths were identified during the 23 years of follow-up. Individuals with PRISm and AO exhibited a higher risk of lung cancer incidence and mortality compared with those with normal lung function. The adjusted HRs and 95% CIs were 1.14 (1.03 to 1.26) and 1.23 (1.10 to 1.37) in the overall cohort, and 1.08 (0.93 to 1.24), and 1.23 (1.05 to 1.45) in the never-smoker cohort. The risks of both developing and dying of lung cancer increased with the severity levels of lung function impairments and lower FEV1 values.

CONCLUSION

Impaired lung function is associated with increased risks of developing lung cancer and subsequent mortality. The study highlights the importance of considering lung function in lung cancer screening for better candidate selection.

Low lung function in Bipolar Disorder and Schizophrenia: a hidden risk

Introduction: People with serious mental illness (SMI), such as schizophrenia and bipolar disorder, have a higher risk of premature morbidity and mortality. In the general population, impaired lung function is associated with increased morbidity and mortality. We compared lung function between people with and without serious mental illnesses using a cross-sectional study in 9 community mental health units. Methods: Subjects aged 40-70 years with a diagnosis of schizophrenia or bipolar disorder were recruited consecutively. The controls had no psychiatric diagnosis and were not receiving any psychotropics. Spirometry was performed by a trained nurse. We used the 2021 American Thoracic Society/European Respiratory Society standards for the interpretation of the spirometry results. Results: We studied 287 subjects. People with SMI (n = 169) had lower spirometry values than those without a psychiatric diagnosis (n = 118). An abnormal spirometry pattern (36.1% vs 16.9%, p < 0.001), possible restriction or non-specific (Preserved Ratio Impaired Spirometry [PRISm]) pattern (17.8% vs 7.6%, p = 0.014), and pattern of airflow obstruction or possible mixed disorder (18.3% vs 9.3%, p = 0.033) were more frequent in people with SMI. Multivariate analyses showed that the PRISm pattern was associated with abdominal circumference (odds ratio [OR] 1.05, 95%CI 1.03-1.08) and that the pattern of airflow obstruction or possible mixed disorder was associated with smoking behavior (OR 5.15, 95%CI 2.06-15.7). Conclusion: People with SMI have impaired lung function, with up to one-third of them showing an abnormal spirometry pattern. This suggests that regular monitoring of lung function and addressing modifiable risk factors, such as tobacco use and obesity, in this population is of paramount importance.

Cardiac troponin I as predictor for cardiac and other mortality in the German randomized lung cancer screening trial (LUSI)

Cardiac Troponin I (cTnI) could be used to identify individuals at elevated risk of cardiac death in lung cancer (LC) screening settings. In a population-based, randomized LC screening trial in Germany ("LUSI" study) serum cTnI was measured by high-sensitivity assay in blood samples collected at baseline, and categorized into unquantifiable/low (< 6 ng/L), intermediate (≥ 6-15 ng/L), and elevated (≥ 16 ng/L). Cox proportional-hazard models were used to estimate risk of all-cause and cardiac mortality with cTnI levels. After exclusion criteria, 3653 participants were included for our analyses, of which 82.4% had low, 12.8% intermediate and 4.8% elevated cTnI, respectively. Over a median follow up of 11.87 years a total of 439 deaths occurred, including 67 caused by cardiac events. Within the first 5 years after cTnI measurement, intermediate or elevated cTnI levels showed approximately 1.7 (HR = 1.69 [95% CI 0.57-5.02) and 4.7-fold (HR = 4.66 [1.73-12.50]) increases in risk of cardiac death relative to individuals with unquantifiable/low cTnI, independently of age, sex, smoking and other risk factors. Within this time interval, a risk model based on age, sex, BMI, smoking history and cTnI showed a combined area under the ROC curve (AUC) of 73.6 (58.1-87.3), as compared to 70.4 (53.3-83.5) for a model without cTnI. Over the time interval of > 5-10 years after blood donation, the relative risk associations with cTnI and were weaker. cTnI showed no association with mortality from any other (non-cardiac) cause. Our findings show that cTnI may be of use for identifying individuals at elevated risk specifically of short-term cardiac mortality in the context of LC screening.

Association of preserved ratio impaired spirometry with mortality: a systematic review and meta-analysis

BACKGROUND

Preserved ratio impaired spirometry (PRISm) is prevalent within the general population. Increased mortality has been reported among subjects with PRISm, but the evidence has never been summarised. This systematic review aims to synthesise evidence on the association between PRISm and the risk of all-cause, cardiovascular and respiratory-related mortality.

METHODS

We systematically searched MEDLINE, Embase and Web of Science for population-based cohort studies from inception to April 2023 using the terms related to impaired spirometry and mortality. Titles and abstracts were screened to identify eligible studies that reported mortality estimates for individuals with PRISm. We excluded studies that adopted other definitions of impaired spirometry, had a specific study setting (e.g. HIV patients), had an insufficient follow-up period (<1 year) or reported duplicated data. Random-effects meta-analysis was used to produce pooled hazard ratio (HR) with 95% confidence intervals. Between-study heterogeneity was assessed with I2.

RESULTS

Eight studies met the inclusion criteria involving 40 699 individuals with PRISm. All included studies reported increased risk of all-cause mortality among adults with PRISm. Meta-analysis showed that PRISm was associated with an increased risk of all-cause mortality (pooled HR 1.71, 95% CI 1.51-1.93; I2=64%), cardiovascular mortality (pooled HR 1.57, 95% CI 1.44-1.72; I2=35%) and respiratory-related mortality (pooled HR 1.97, 95% CI 1.55-2.49; I2=0%).

CONCLUSIONS

Individuals with PRISm have a significantly increased risk of mortality compared with those with normal spirometry.

Serum-based biomarkers associated with lung cancer risk and cause-specific mortality in the German randomized Lung Cancer Screening Intervention (LUSI) trial

Background

Lung cancer (LC) screening can be optimized using individuals' estimated risks of having a detectable lung tumor, as well as of mortality risk by competing causes, to guide decisions on screening eligibility, ideal screening intervals and stopping ages. Besides age, sex and smoking history, blood-based biomarkers may be used to improve the assessment of LC risk and risk of mortality by competing causes.

Methods

In the German randomized Lung Screening Intervention Trial (LUSI), we measured growth/differentiation factor-15 (GDF-15), interleukin-6 (IL-6), C-reactive protein (CRP) and N-terminal pro-brain natriuretic protein (NT-proBNP), in blood serum samples collected at start of the trial. Participants in the computed tomography (CT)-screening arm also had a pulmonary function test. Regression models were used to examine these markers as predictors for impaired lung function, LC risk and mortality due to LC or other causes, independently of age, sex and smoking history.

Results

Our models showed increases in LC risk among participants with elevated serum levels of GDF-15 [odds ratio (OR)Q4-Q1 =2.47, 95% confidence interval (CI): 1.49-4.26], IL-6 [ORQ4-Q1 =2.36 (1.43-4.00)] and CRP [ORQ4-Q1 =1.81 (1.08-2.75)]. Likewise, proportional hazards models showed increased risks for LC-related mortality, hazard ratio (HR)Q4-Q1 of 4.63 (95% CI: 2.13-10.07) for GDF-15, 3.56 (1.72-7.37) for IL-6 and 2.34 (1.24-4.39) for CRP. All four markers were associated with increased risk of mortality by causes other than LC, with strongest associations for GDF-15 [HRQ4-Q1 =3.04 (2.09-4.43)] and IL-6 [HRQ4-Q1 =2.98 (2.08-4.28)]. Significant associations were also observed between IL-6, CRP, GDF-15 and impaired pulmonary function [chronic obstructive pulmonary disease (COPD), preserved ratio impaired spirometry (PRISm)]. Multi-marker models identified GDF-15 and IL-6 as joint risk predictors for risk of LC diagnosis, without further discrimination by CRP or NT-proBNP. A model based on age, sex, smoking-related variables, GFD-15 and IL-6 provided moderately strong discrimination for prediction of LC diagnoses within 9 years after blood sampling [area under the curve (AUC) =74.3% (57.3-90.2%)], compared to 67.0% (49.3-84.8%) for a model without biomarkers. For mortality by competing causes, a model including biomarkers resulted in an AUC of 76.2% (66.6-85.3%)], compared to 70.0% (60.9-77.9%) a model including age, sex and smoking variables.

Conclusions

Serum GDF-15 and IL-6 may be useful indicators for estimating risks for LC and competing mortality among long-term smokers participating in LC screening, to optimize LC screening strategies.

Predictive Value of Skeletal Muscle Function Test Combined with Climbing Test for Postoperative Cardiopulmonary Complications in Patients with COPD and Concurrent Lung Cancer

Purpose

To explore the predictive value of skeletal muscle function measurement combined with stair climbing test for postoperative cardiopulmonary complications in patients with chronic obstructive pulmonary disease (COPD) and non-small cell lung cancer (NSCLC).

Patients and Methods

A prospective study was conducted from June 2022 to July 2023 at West China Hospital of Sichuan University, including 335 COPD patients with lung cancer who underwent surgery. The patients were divided into two groups based on the occurrence of postoperative cardiopulmonary complications: the complication group and the non-complication group. The demographic data, including gender, age, smoking history, quadriceps strength, body mass index (BMI), respiratory muscle strength, 6-minute walk test (6MWD), stair climbing test, and preoperative pulmonary function tests, were compared between the two groups. Logistic regression analysis was performed to evaluate the predictive power of each parameter for postoperative cardiopulmonary complications.

Results

Among the enrolled patients, 103 (30.7%) developed postoperative cardiopulmonary complications. Significant differences were observed between the two groups in terms of quadriceps strength, respiratory muscle strength, 6MWD, smoking history, stair climbing test, DLCO%, FEV1%, heart rate, oxygen saturation, surgical duration, surgical approach, resection range, and blood loss (P<0.05). Logistic regression analysis revealed that respiratory muscle strength, quadriceps strength, stair climbing test, FEV1%, DLCO%, ΔHR, ΔSPO2, surgical approach were identified as risk factors for postoperative cardiopulmonary complications in patients with COPD and lung cancer.

Conclusion

Skeletal muscle function measurement, stair climbing test, FEV1, surgical approach, and DLCO% can serve as assessment tools for surgical risk in patients with COPD and lung cancer. They can predict the occurrence of postoperative cardiopulmonary complications to a certain extent, providing valuable predictive value for these complications in patients with COPD and NSCLC.

Prevalence, diagnosis, and treatment of chronic obstructive pulmonary disease in a hospitalized lung cancer population: a single center study

Background

Chronic obstructive pulmonary disease (COPD) often coexists with lung cancer (LC) and has a detrimental effect on the prognosis of LC patients. Presently, there is a lack of adequate assessment regarding the management of COPD in LC patients. This study assessed the screening, prevalence, diagnosis and treatment of COPD in hospitalized LC patients and compared the management practices between two departments at our hospital.

Methods

We retrospectively assessed the data of 3,578 patients diagnosed with primary LC in the Department of Respiratory and Critical Care Medicine and the Department of Thoracic Surgery from January 2019 to December 2020. We also compared the rate of spirometry, COPD diagnosis and COPD inhalation treatment between the LC patients from both departments, the proportion of patients aware of their COPD diagnosis and adhered to inhaled therapy, and analyzed factors influencing COPD diagnosis and inhalation treatment.

Results

A total of 2,762 (77.2%) LC patients underwent spirometry, and the observed spirometry-defined COPD prevalence was 25.0% (690/2,762). The proportion of spirometry performed in the Department of Thoracic Surgery was significantly higher than in the Department of Respiratory and Critical Care Medicine (90.5% vs. 62.9%; P<0.001). The overall COPD diagnosis rate recorded in the discharge diagnosis in the 690 spirometry-defined COPD patients was 46.5% (321/690), and the COPD treatment rate during hospitalization was 45.2% (312/690). In addition, physicians from the Department of Respiratory and Critical Care Medicine had a higher diagnostic rate than surgeons from the Department of Thoracic Surgery (69.1% vs. 7.5%; P<0.001), as well as a better-standardized COPD treatment rate (60.6% vs. 18.6%; P<0.001). Further, the proportion of COPD inhalation treatment was higher among LC patients with COPD recorded in discharge diagnosis (74.8% vs. 19.5%; P<0.001), and multivariate logistic regression analysis showed that COPD recorded in discharge diagnosis significantly increased the proportion of COPD awareness post-hospitalization (P<0.001).

Conclusions

This study showed that COPD could be a frequently undiagnosed and undertreated condition among LC patients, especially those hospitalized in a surgical ward. Additionally, a discharge diagnosis of COPD may increase the rate of inhalation treatment and awareness of the condition in LC patients.

Should we be screening for COPD? - looking through the lens of lung cancer screening

INTRODUCTION

In May 2022, the US Preventive Services Task Force published their recommendation against screening for chronic obstructive pulmonary disease (COPD) in asymptomatic adults. However, we argue the routine use of spirometry in both asymptomatic and symptomatic high-risk smokers has utility.

AREAS COVERED

We provide published and unpublished observations from a secondary analyses of the American College of Radiology Imaging Network (ACRIN), arm of the National Lung Screening Trial, including 18,463 high-risk current or former smokers who underwent pre-bronchodilator spirometry at baseline. According to history alone, 20% reported a prior diagnosis of 'COPD,' although only 11% (about one half), actually had airflow limitation (Diagnosed COPD) and 9% had Global Initiative for Obstructive Pulmonary Disease GOLD 0 Pre-COPD. Of the remaining 80% of 'asymptomatic' screening participants, 23% had airflow limitation (Screen-detected COPD) and 13% had preserved ratio impaired spirometry (PRISm). This means 45% of this high-risk cohort were reclassified by spirometry, and together with comorbid disease, identified subgroups where lung cancer screening efficacy could be optimized by between 2-6 fold.

EXPERT OPINION

Our preliminary findings suggest lung cancer screening outcomes vary according to 'new' COPD-related spirometric-defined subgroups and that screening spirometry, together with comorbid disease, identifies those for whom lung cancer screening is mostly beneficial or potentially harmful.

Lung Cancer Screening with Low-Dose CT: What We Have Learned in Two Decades of ITALUNG and What Is Yet to Be Addressed

The ITALUNG trial started in 2004 and compared lung cancer (LC) and other-causes mortality in 55-69 years-aged smokers and ex-smokers who were randomized to four annual chest low-dose CT (LDCT) or usual care. ITALUNG showed a lower LC and cardiovascular mortality in the screened subjects after 13 years of follow-up, especially in women, and produced many ancillary studies. They included recruitment results of a population-based mimicking approach, development of software for computer-aided diagnosis (CAD) and lung nodules volumetry, LDCT assessment of pulmonary emphysema and coronary artery calcifications (CAC) and their relevance to long-term mortality, results of a smoking-cessation intervention, assessment of the radiations dose associated with screening LDCT, and the results of biomarkers assays. Moreover, ITALUNG data indicated that screen-detected LCs are mostly already present at baseline LDCT, can present as lung cancer associated with cystic airspaces, and can be multiple. However, several issues of LC screening are still unaddressed. They include the annual vs. biennial pace of LDCT, choice between opportunistic or population-based recruitment. and between uni or multi-centre screening, implementation of CAD-assisted reading, containment of false positive and negative LDCT results, incorporation of emphysema. and CAC quantification in models of personalized LC and mortality risk, validation of ultra-LDCT acquisitions, optimization of the smoking-cessation intervention. and prospective validation of the biomarkers.

Pulmonary emphysema and coronary artery calcifications at baseline LDCT and long-term mortality in smokers and former smokers of the ITALUNG screening trial

OBJECTIVES

Cardiovascular disease (CVD), lung cancer (LC), and respiratory diseases are main causes of death in smokers and former smokers undergoing low-dose computed tomography (LDCT) for LC screening. We assessed whether quantification of pulmonary emphysematous changes at baseline LDCT has a predictive value concerning long-term mortality.

METHODS

In this longitudinal study, we assessed pulmonary emphysematous changes with densitometry (volume corrected relative area below - 950 Hounsfield units) and coronary artery calcifications (CAC) with a 0-3 visual scale in baseline LDCT of 524 participants in the ITALUNG trial and analyzed their association with mortality after 13.6 years of follow-up using conventional statistics and a machine learning approach.

RESULTS

Pulmonary emphysematous changes were present in 32.3% of subjects and were mild (6% ≤ RA950 ≤ 9%) in 14.9% and moderate-severe (RA950 > 9%) in 17.4%. CAC were present in 67% of subjects (mild in 34.7%, moderate-severe in 32.2%). In the follow-up, 81 (15.4%) subjects died (20 of LC, 28 of other cancers, 15 of CVD, 4 of respiratory disease, and 14 of other conditions). After adjusting for age, sex, smoking history, and CAC, moderate-severe emphysema was significantly associated with overall (OR 2.22; 95CI 1.34-3.70) and CVD (OR 3.66; 95CI 1.21-11.04) mortality. Machine learning showed that RA950 was the best single feature predictive of overall and CVD mortality.

CONCLUSIONS

Moderate-severe pulmonary emphysematous changes are an independent predictor of long-term overall and CVD mortality in subjects participating in LC screening and should be incorporated in the post-test calculation of the individual mortality risk profile.

KEY POINTS

• Densitometry allows quantification of pulmonary emphysematous changes in low-dose CT examinations for lung cancer screening. • Emphysematous lung density changes are an independent predictor of long-term overall and cardio-vascular disease mortality in smokers and former smokers undergoing screening. • Emphysematous changes quantification should be included in the post-test calculation of the individual mortality risk profile.