Impact of coexistent preserved ratio impaired spirometry on the survival of patients with lung cancer: Analysis of data from the Korean Association for Lung Cancer Registry

Preserved ratio impaired spirometry: clinical, imaging and artificial intelligence perspective

Preserved ratio impaired spirometry (PRISm) is a pulmonary function pattern characterized by a forced expiratory volume in one second (FEV1) to forced vital capacity ratio greater than 0.70, with an FEV1 that is below 80% of the predicted value, even after the use of bronchodilators. PRISm is considered a form of "Pre-Chronic Obstructive Pulmonary Disease (Pre-COPD)" within the broader scope of COPD. Clinically, it presents with respiratory symptoms and is more commonly observed in individuals with high body mass index, females, and those who are current smokers. Additionally, it is frequently associated with metabolic disorders and cardiovascular diseases. Regarding prognosis, PRISm shows considerable variation, ranging from improvement in lung function to the development of COPD. In this article, we review the epidemiology, comorbidities, and clinical outcomes of PRISm, with a particular emphasis on the crucial role of imaging assessments, especially computed tomography scans and magnetic resonance imaging (MRI) technology, in diagnosing, evaluating, and predicting the prognosis of PRISm. Comprehensive imaging provides a quantitative evaluation of lung volume, density, airways, and vasculature, while MRI technology can directly quantify ventilation function and pulmonary blood flow. We also emphasize the future potential of X-ray technology in this field. Moreover, the article discusses the application of artificial intelligence, including its role in predicting PRISm subtypes and modeling ventilation function.

The prevalence and mortality risks of PRISm and COPD in the United States from NHANES 2007-2012

BACKGROUND

We estimated the prevalence and mortality risks of preserved ratio impaired spirometry (PRISm) and chronic obstructive pulmonary disease (COPD) in the US adult population.

METHODS

We linked three waves of pre-bronchodilator spirometry data from the US National Health and Nutritional Examination Survey (2007-2012) with the National Death Index. The analytic sample included adults ages 20 to 79 without missing data on age, sex, height, BMI, race/ethnicity, and smoking status. We defined COPD (GOLD 1, 2, and 3-4) and PRISm using FEV1/FVC cut points by the Global Initiative for Chronic Obstructive Lung Disease (GOLD). We compared the prevalence of GOLD stages and PRISm by covariates across the three waves. We estimated adjusted all-cause and cause-specific mortality risks by COPD stage and PRISm using all three waves combined.

RESULTS

Prevalence of COPD and PRISm from 2007-2012 ranged from 13.1%-14.3% and 9.6%-10.2%, respectively. We found significant differences in prevalence by sex, age, smoking status, and race/ethnicity. Males had higher rates of COPD regardless of stage, while females had higher rates of PRISm. COPD prevalence increased with age, but not PRISm, which was highest among middle-aged individuals. Compared to current and never smokers, former smokers showed lower rates of PRISm but higher rates of GOLD 1. COPD prevalence was highest among non-Hispanic White individuals, and PRISm was notably higher among non-Hispanic Black individuals (range 31.4%-37.4%). We found associations between PRISm and all-cause mortality (hazard ratio [HR]: 2.3 95% CI: 1.9-2.9) and various cause-specific deaths (HR ranges: 2.0-5.3). We also found associations between GOLD 2 (HR: 2.1, 95% CI: 1.7-2.6) or higher (HR: 4.2, 95% CI: 2.7-6.5) and all-cause mortality. Cause-specific mortality risk varied within COPD stages but typically increased with higher GOLD stage.

CONCLUSIONS

The prevalence of COPD and PRISm remained stable from 2007-2012. Greater attention should be paid to the potential impacts of PRISm due to its higher prevalence in minority groups and its associations with mortality across various causes including cancer.

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.

The value of lung function assessment and Testin expression detection in clinicopathological features and prognosis of NSCLC patients

OBJECTIVE

The aim of this study is to investigate the clinical value and potential prognostic significance of lung function assessment and Testin expression in non-small cell lung cancer (NSCLC) patients.

METHODS

The NSCLC patients were classified into three groups according to lung function: group of normal lung function, group of PRISm (preserved ratio impaired spirometry) (FEV1, forced expiratory volume during the first second < 80% predicted and FEV1/FVC (forced vital capacity) ≥ 70%) and group of COPD (chronic obstructive pulmonary disease) (FEV1/FVC < 70%). The pre-operational clinicopathological characteristics of these patients were recorded and the markers of systemic inflammatory response, including neutrophil to lymphocyte ratio (NLR), lymphocyte to monocyte ratio (LMR), platelet to lymphocyte ratio (PLR) and eosinophils (EOS), were compared between three groups. The expression of Testin in NSCLC samples was detected by IHC and we further explored the correlation between Testin expression and clinicopathological characteristics and prognosis of NSCLC patients. Finally, Cox regression analysis was conducted to study the prognostic factors of NSCLC patients.

RESULTS

Of the 158 NSCLC patients, percentages of normal lung function, PRISm and COPD were 41.4%, 22.8% and 36.1%, respectively. Patients with tumor in the left lung were more likely to have pulmonary dysfunction (PRISm and COPD) than the right lung. The markers of systemic inflammatory response showed differences to various degree in the three groups and NSCLC patients with PRISm or COPD presented more unfavorable prognosis than patients with normal function. The expression of Testin correlated with lymph node metastasis, TNM stage and tumor invasion of NSCLC patients. Moreover, patients with low Testin expression exhibited poorer disease-free survival and overall survival than those with high Testin expression. In Cox regression analysis, we found that PRISm, COPD and Testin expression served as prognostic factors in NSCLC patients.

CONCLUSIONS

The presence of COPD or PRISm influenced systemic inflammatory response and prognosis of NSCLC patients. Testin expression correlated with clinicopathological features and could be potentially used as a prognostic marker in NSCLC.

Impact of preserved ratio impaired spirometry on coronary artery calcium score progression: a longitudinal cohort study

Background

Preserved ratio impaired spirometry (PRISm) is associated with increased cardiovascular disease (CVD) risk and mortality. However, a causal relationship between PRISm and CVD remains unclear. We investigated the progression of coronary artery calcium (CAC) scores based on the presence of PRISm and reduced forced vital capacity (FVC).

Methods

This retrospective cohort study included 11 420 participants aged ≥40 years with forced expiratory volume in 1 s (FEV1)/FVC ≥0.7 who underwent at least two health screening examinations with coronary computed tomography scan between 2003 and 2020, and were without a history of CVD or interstitial lung disease. Participants with PRISm, defined as FEV1/FVC ≥0.7 and FEV1 <80% predicted, were further divided by low FVC (FVC <80% predicted). We estimated the 5-year progression rates of CAC by comparing participants with and without PRISm at baseline using mixed linear models.

Results

Of the 11 420 participants, 8536 (75%), 811 (7%) and 2073 (18%) had normal spirometry, PRISm with normal FVC and PRISm with low FVC, respectively. During the mean (range) follow-up of 6.0 (0.5-17.2) years, the multivariable adjusted ratio of 5-year CAC progression rates comparing participants with PRISm to those with normal spirometry was 1.08 (95% CI 1.04-1.13). This rate was higher in participants with PRISm with low FVC (1.21 (95% CI 1.12-1.30)) than in those with normal FVC.

Conclusion

In this longitudinal cohort study of subjects without a history of CVD, PRISm was significantly associated with CAC progression, which was more evident in the group with PRISm and low FVC.

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.

Hyperinflation and reduced diffusing capacity predict prognosis in SCLC: value of extended pre-therapeutic lung function testing

BACKGROUND

Small cell lung cancer (SCLC) is characterized by aggressive growth and poor prognosis. Although SCLC affects nearly exclusively heavy smokers and leads to frequent respiratory symptoms, the impact of pre-therapeutic lung function testing in SCLC is sparely investigated until now. Therefore, we sought to examine whether we could find prognostic markers in pre-therapeutic lung function testing of SCLC patients.

PATIENTS AND METHODS

We retrospectively analysed a cohort of 205 patients with the diagnosis of SCLC between 2010 and 2018. Pre-therapeutic values of spirometry, body plethysmography and measurement of diffusing capacity was extracted from patients' charts. Comparisons between groups were performed using the Mann-Whitney U-test or by chi-square tests as appropriate. Kaplan-Meier analyses and COX-regression models were performed to correlate lung function parameters with patients' outcome.

RESULTS

Airway obstruction itself, or the diagnosis chronic obstructive pulmonary disease (COPD) based on GOLD definitions did not correlate with survival in SCLC patients. Hyperinflation measured by increased residual volume and residual volume to total lung capacity ratio (log-rank p < 0.001) and reduced diffusing capacity (log-rank p = 0.007) were associated with reduced survival. Furthermore, patients with hyperinflation as well as impairments in gas exchange representing an emphysematic phenotype had the worst outcome (log-rank p < 0.001).

CONCLUSION

We recommend including body plethysmography and measurement of diffusing capacity in the pre-therapeutic assessment of SCLC patients. Our findings suggest that reduction of hyperinflation may lead to better outcome in SCLC patients. Thus, in addition to effective tumour therapy, adequate therapy of the comorbidity of COPD should also be provided. In particular, measures to reduce hyperinflation by means of dual bronchodilation as well as respiratory physiotherapy should be further assessed in this setting.

Spontaneous Ventilation Video-Assisted Thoracoscopic Surgery for Non-small-cell Lung Cancer Patients With Poor Lung Function: Short- and Long-Term Outcomes

Objective

The goal of this study was to explore the feasibility and safety of spontaneous ventilation video-assisted thoracoscopic surgery (SV-VATS) for non-small-cell lung cancer (NSCLC) patients with poor lung function.

Methods

NSCLC patients with poor lung function who underwent SV-VATS or mechanical ventilation VATS (MV-VATS) from 2011 to 2018 were analyzed. 1:2 Propensity score matching (PSM) was applied, and the short- and long-term outcomes between the SV-VATS group and the MV-VATS group were compared.

Results

Anesthesia time (226.18 ± 64.89 min vs. 248.27 ± 76.07 min; P = 0.03), operative time (140.85 ± 76.07 min vs. 163.12 ± 69.37 min; P = 0.01), days of postoperative hospitalization (7.29 ± 3.35 days vs. 8.40 ± 7.89 days; P = 0.04), and days of chest tube use (4.15 ± 2.89 days vs. 5.15 ± 3.54 days; P = 0.01), the number of N1 station lymph node dissection (2.94 ± 3.24 vs. 4.34 ± 4.15; P = 0.005) and systemic immune-inflammation index (3855.43 ± 3618.61 vs. 2908.11 ± 2933.89; P = 0.04) were lower in SV-VATS group. Overall survival and disease-free survival were not significantly different between the two groups (OS: HR 0.66, 95% CI: 0.41–1.07, P = 0.09; DFS: HR 0.78, 95% CI: 0.42–1.45, P = 0.43).

Conclusions

Comparable short-term and long-term outcomes indicated that SV-VATS is a feasible and safe method and might be an alternative to MV-VATS when managing NSCLC patients with poor lung function.