Pulmonary emphysema subtypes defined by unsupervised machine learning on CT scans

BACKGROUND

Treatment and preventative advances for chronic obstructive pulmonary disease (COPD) have been slow due, in part, to limited subphenotypes. We tested if unsupervised machine learning on CT images would discover CT emphysema subtypes with distinct characteristics, prognoses and genetic associations.

METHODS

New CT emphysema subtypes were identified by unsupervised machine learning on only the texture and location of emphysematous regions on CT scans from 2853 participants in the Subpopulations and Intermediate Outcome Measures in COPD Study (SPIROMICS), a COPD case-control study, followed by data reduction. Subtypes were compared with symptoms and physiology among 2949 participants in the population-based Multi-Ethnic Study of Atherosclerosis (MESA) Lung Study and with prognosis among 6658 MESA participants. Associations with genome-wide single-nucleotide-polymorphisms were examined.

RESULTS

The algorithm discovered six reproducible (interlearner intraclass correlation coefficient, 0.91-1.00) CT emphysema subtypes. The most common subtype in SPIROMICS, the combined bronchitis-apical subtype, was associated with chronic bronchitis, accelerated lung function decline, hospitalisations, deaths, incident airflow limitation and a gene variant near DRD1, which is implicated in mucin hypersecretion (p=1.1 ×10-8). The second, the diffuse subtype was associated with lower weight, respiratory hospitalisations and deaths, and incident airflow limitation. The third was associated with age only. The fourth and fifth visually resembled combined pulmonary fibrosis emphysema and had distinct symptoms, physiology, prognosis and genetic associations. The sixth visually resembled vanishing lung syndrome.

CONCLUSION

Large-scale unsupervised machine learning on CT scans defined six reproducible, familiar CT emphysema subtypes that suggest paths to specific diagnosis and personalised therapies in COPD and pre-COPD.

Novel Subtypes of Pulmonary Emphysema Based on Spatially-Informed Lung Texture Learning: The Multi-Ethnic Study of Atherosclerosis (MESA) COPD Study

Pulmonary emphysema overlaps considerably with chronic obstructive pulmonary disease (COPD), and is traditionally subcategorized into three subtypes previously identified on autopsy. Unsupervised learning of emphysema subtypes on computed tomography (CT) opens the way to new definitions of emphysema subtypes and eliminates the need of thorough manual labeling. However, CT-based emphysema subtypes have been limited to texture-based patterns without considering spatial location. In this work, we introduce a standardized spatial mapping of the lung for quantitative study of lung texture location and propose a novel framework for combining spatial and texture information to discover spatially-informed lung texture patterns (sLTPs) that represent novel emphysema subtype candidates. Exploiting two cohorts of full-lung CT scans from the MESA COPD (n = 317) and EMCAP (n = 22) studies, we first show that our spatial mapping enables population-wide study of emphysema spatial location. We then evaluate the characteristics of the sLTPs discovered on MESA COPD, and show that they are reproducible, able to encode standard emphysema subtypes, and associated with physiological symptoms.

Hypersensitivity pneumonitis: Airway-centered pulmonary fibrosis on chest CT

BACKGROUND

To evaluate the chest CT appearance of patients with a clinicopathologic diagnosis of hypersensitivity pneumonia.

METHODS

IRB approval was obtained for a retrospective review of patients with a preoperative CT scan, a surgical pathology report from a transbronchial biopsy or wedge resection consistent with hypersensitivity pneumonitis, and a pulmonary consultation, which also supported the diagnosis. The pathology report was evaluated for granulomas, airway-centered fibrosis, microscopic honeycombing, and fibroblast foci. The medical records were reviewed for any known antigen exposure. Patients were separated into two groups; those with and without a known antigen exposure. The CT scans were assessed for distribution of fibrosis: upper lobe or lower lobe predominance, airway-centered versus peripheral distribution, three-density pattern, and honeycombing.

RESULTS

264 pathology reports included the term chronic hypersensitivity pneumonitis (CHP). Thirty-eight of the patients had a pulmonologist who gave the patient a working diagnosis of CHP. The average age of these patients was 64 years, and 21/38 were women. Seventeen of the 38 patients had at least one antigen exposure described in the medical records. All the patients had fibrosis along the airways on chest CT. Both known antigen exposure and no known antigen patients had upper and lower lung-predominant fibrosis. There were more patients with hiatal hernias in the unknown antigen group. Honeycombing was an uncommon finding.

CONCLUSION

Airway-centered fibrosis was present on chest CT in all 38 patients with CHP (100%), with or without known antigen exposure.

Quantifying normal lung in pulmonary fibrosis: CT analysis and correlation with %DLCO

BACKGROUND

Chest CT scans are routinely obtained to monitor disease progression in pulmonary fibrosis. However, radiologists do not employ a standardized system for quantitative description of the severity of the disease. Development and validation of a grading system offers potential for enhancing the information that radiologists provide clinicians.

STUDY DESIGN AND METHODS

Our retrospective review analyzed 100 sequential patients with usual interstitial pneumonitis (UIP) on HRCT scans from 2018 and 2019. A radiologic scoring system evaluated the percent of normal lung on the basis of a 0-5 point scale per lobe (findings for the right middle lobe were included in the right upper lobe score), yielding an overall additive numerical score on a scale of 20 (completely normal lung) to 0 (no normal lung). Two radiologists quantified the percentage of normal lung by consensus agreement. Percent DLCO as well as demographic data were obtained from the medical record. Statistical analysis was performed using Spearman correlation to assess correlation between grade and percent DLCO.

RESULTS

96 patients met the inclusion criteria; average age was 71, 68% were male. Score on CT scan ranged from 18 to 4; average 10.9, SD 3.58. The single-breath diffusing capacity (percent DLCO) ranged from 88% to 17%; mean 44.5%, SD 14.3%. Spearman's correlation for CT score and percent DLCO was 0.622, P < 0.001.

CONCLUSION

This scoring system quantifying the amount of normal lung on chest CT of patients with UIP correlated significantly with percent DLCO (P < 0.001) and appears to offer a promising quantitative measure to assess severity of disease.

Interstitial lung abnormalities detected incidentally on CT: a Position Paper from the Fleischner Society

The term interstitial lung abnormalities refers to specific CT findings that are potentially compatible with interstitial lung disease in patients without clinical suspicion of the disease. Interstitial lung abnormalities are increasingly recognised as a common feature on CT of the lung in older individuals, occurring in 4-9% of smokers and 2-7% of non-smokers. Identification of interstitial lung abnormalities will increase with implementation of lung cancer screening, along with increased use of CT for other diagnostic purposes. These abnormalities are associated with radiological progression, increased mortality, and the risk of complications from medical interventions, such as chemotherapy and surgery. Management requires distinguishing interstitial lung abnormalities that represent clinically significant interstitial lung disease from those that are subclinical. In particular, it is important to identify the subpleural fibrotic subtype, which is more likely to progress and to be associated with mortality. This multidisciplinary Position Paper by the Fleischner Society addresses important issues regarding interstitial lung abnormalities, including standardisation of the definition and terminology; predisposing risk factors; clinical outcomes; options for initial evaluation, monitoring, and management; the role of quantitative evaluation; and future research needs.

COPDGene® 2019: Redefining the Diagnosis of Chronic Obstructive Pulmonary Disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) remains a major cause of morbidity and mortality. Present-day diagnostic criteria are largely based solely on spirometric criteria. Accumulating evidence has identified a substantial number of individuals without spirometric evidence of COPD who suffer from respiratory symptoms and/or increased morbidity and mortality. There is a clear need for an expanded definition of COPD that is linked to physiologic, structural (computed tomography [CT]) and clinical evidence of disease. Using data from the COPD Genetic Epidemiology study (COPDGene®), we hypothesized that an integrated approach that includes environmental exposure, clinical symptoms, chest CT imaging and spirometry better defines disease and captures the likelihood of progression of respiratory obstruction and mortality.

METHODS

Four key disease characteristics - environmental exposure (cigarette smoking), clinical symptoms (dyspnea and/or chronic bronchitis), chest CT imaging abnormalities (emphysema, gas trapping and/or airway wall thickening), and abnormal spirometry - were evaluated in a group of 8784 current and former smokers who were participants in COPDGene® Phase 1. Using these 4 disease characteristics, 8 categories of participants were identified and evaluated for odds of spirometric disease progression (FEV1 > 350 ml loss over 5 years), and the hazard ratio for all-cause mortality was examined.

RESULTS

Using smokers without symptoms, CT imaging abnormalities or airflow obstruction as the reference population, individuals were classified as Possible COPD, Probable COPD and Definite COPD. Current Global initiative for obstructive Lung Disease (GOLD) criteria would diagnose 4062 (46%) of the 8784 study participants with COPD. The proposed COPDGene® 2019 diagnostic criteria would add an additional 3144 participants. Under the new criteria, 82% of the 8784 study participants would be diagnosed with Possible, Probable or Definite COPD. These COPD groups showed increased risk of disease progression and mortality. Mortality increased in patients as the number of their COPD characteristics increased, with a maximum hazard ratio for all cause-mortality of 5.18 (95% confidence interval [CI]: 4.15-6.48) in those with all 4 disease characteristics.

CONCLUSIONS

A substantial portion of smokers with respiratory symptoms and imaging abnormalities do not manifest spirometric obstruction as defined by population normals. These individuals are at significant risk of death and spirometric disease progression. We propose to redefine the diagnosis of COPD through an integrated approach using environmental exposure, clinical symptoms, CT imaging and spirometric criteria. These expanded criteria offer the potential to stimulate both current and future interventions that could slow or halt disease progression in patients before disability or irreversible lung structural changes develop.

Ambient air pollution and pulmonary vascular volume on computed tomography: the MESA Air Pollution and Lung cohort studies

BACKGROUND

Air pollution alters small pulmonary vessels in animal models. We hypothesised that long-term ambient air pollution exposure would be associated with differences in pulmonary vascular volumes in a population-based study.

METHODS

The Multi-Ethnic Study of Atherosclerosis recruited adults in six US cities. Personalised long-term exposures to ambient black carbon, nitrogen dioxide (NO₂), oxides of nitrogen (NO _x ), particulate matter with a 50% cut-off aerodynamic diameter of <2.5 μm (PM_2.5) and ozone were estimated using spatiotemporal models. In 2010-2012, total pulmonary vascular volume was measured as the volume of detectable pulmonary arteries and veins, including vessel walls and luminal blood volume, on noncontrast chest computed tomography (TPVV_CT). Peripheral TPVV_CT was limited to the peripheral 2 cm to isolate smaller vessels. Linear regression adjusted for demographics, anthropometrics, smoking, second-hand smoke, renal function and scanner manufacturer.

RESULTS

The mean±sd age of the 3023 participants was 69.3±9.3 years; 46% were never-smokers. Mean exposures were 0.80 μg·m^-3 black carbon, 14.6 ppb NO₂ and 11.0 μg·m^-3 ambient PM_2.5. Mean±sd peripheral TPVV_CT was 79.2±18.2 cm³ and TPVV_CT was 129.3±35.1 cm³. Greater black carbon exposure was associated with a larger peripheral TPVV_CT, including after adjustment for city (mean difference 0.41 (95% CI 0.03-0.79) cm³ per interquartile range; p=0.036). Associations for peripheral TPVV_CT with NO₂ were similar but nonsignificant after city adjustment, while those for PM_2.5 were of similar magnitude but nonsignificant after full adjustment. There were no associations for NO _x or ozone, or between any pollutant and TPVV_CT.

CONCLUSIONS

Long-term black carbon exposure was associated with a larger peripheral TPVV_CT, suggesting diesel exhaust may contribute to remodelling of small pulmonary vessels in the general population.

CT-based Visual Classification of Emphysema: Association with Mortality in the COPDGene Study

Purpose

To determine whether visually assessed patterns of emphysema at CT might provide a simple assessment of mortality risk among cigarette smokers.

Materials and Methods

Of the first 4000 cigarette smokers consecutively enrolled between 2007 and 2011 in this COPDGene study, 3171 had data available for both visual emphysema CT scores and survival. Each CT scan was retrospectively visually scored by two analysts using the Fleischner Society classification system. Severity of emphysema was also evaluated quantitatively by using percentage lung volume occupied by low-attenuation areas (voxels with attenuation of −950 HU or less) (LAA-950). Median duration of follow-up was 7.4 years. Regression analysis for the relationship between imaging patterns and survival was based on the Cox proportional hazards model, with adjustment for age, race, sex, height, weight, pack-years of cigarette smoking, current smoking status, educational level, LAA-950, and (in a second model) forced expiratory volume in 1 second (FEV₁).

Results

Observer agreement in visual scoring was good (weighted κ values, 0.71–0.80). There were 519 deaths in the study cohort. Compared with subjects who did not have visible emphysema, mortality was greater in those with any grade of emphysema beyond trace (adjusted hazard ratios, 1.7, 2.5, 5.0, and 4.1, respectively, for mild centrilobular emphysema, moderate centrilobular emphysema, confluent emphysema, and advanced destructive emphysema, P < .001). This increased mortality generally persisted after adjusting for LAA-950.

Conclusion

The visual presence and severity of emphysema is associated with significantly increased mortality risk, independent of the quantitative severity of emphysema.

Online supplemental material is available for this article.

A Longitudinal Cohort Study of Aspirin Use and Progression of Emphysema-like Lung Characteristics on CT Imaging: The MESA Lung Study

BACKGROUND

Platelet activation reduces pulmonary microvascular blood flow and contributes to inflammation; these factors have been implicated in the pathogenesis of COPD and emphysema. We hypothesized that regular use of aspirin, a platelet inhibitor, would be associated with a slower progression of emphysema-like lung characteristics on CT imaging and a slower decline in lung function.

METHODS

The Multi-Ethnic Study of Atherosclerosis (MESA) enrolled participants 45 to 84 years of age without clinical cardiovascular disease from 2000 to 2002. The MESA Lung Study assessed the percentage of emphysema-like lung below -950 Hounsfield units ("percent emphysema") on cardiac (2000-2007) and full-lung CT scans (2010-2012). Regular aspirin use was defined as 3 or more days per week. Mixed-effect models adjusted for demographics, anthropometric features, smoking, hypertension, angiotensin-converting enzyme inhibitor or angiotensin II-receptor blocker use, C-reactive protein levels, sphingomyelin levels, and scanner factors.

RESULTS

At baseline, the 4,257 participants' mean (± SD) age was 61 ± 10 years, 54% were ever smokers, and 22% used aspirin regularly. On average, percent emphysema increased 0.60 percentage points over 10 years (95% CI, 0.35-0.94). Progression of percent emphysema was slower among regular aspirin users compared with patients who did not use aspirin (fully adjusted model: -0.34% /10 years, 95% CI, -0.60 to -0.08; P = .01). Results were similar in ever smokers and with doses of 81 and 300 to 325 mg and were of greater magnitude among those with airflow limitation. No association was found between aspirin use and change in lung function.

CONCLUSIONS

Regular aspirin use was associated with a more than 50% reduction in the rate of emphysema progression over 10 years. Further study of aspirin and platelets in emphysema may be warranted.

Associations between emphysema-like lung on CT and incident airflow limitation: a general population-based cohort study

Emphysema on CT is associated with accelerated lung function decline in heavy smokers and patients with COPD; however, in the general population, it is not known whether greater emphysema-like lung on CT is associated with incident COPD. We used data from 2045 adult participants without initial prebronchodilator airflow limitation, classified by FEV₁/FVC<0.70, in the Multi-Ethnic Study of Atherosclerosis. Emphysema-like lung on baseline cardiac CT, defined as per cent low attenuation areas_<-950HU>upper limit of normal, was associated with increased odds of incident airflow limitation at 5-year follow-up on both prebronchodilator (adjusted OR 2.62, 95% CI 1.47 to 4.67) and postbronchodilator (adjusted OR 4.38, 95% CI 1.63 to 11.74) spirometry, independent of smoking history. These results support investigation into whether emphysema-like lung could be informative for COPD risk stratification.

Unsupervised Discovery of Spatially-Informed Lung Texture Patterns for Pulmonary Emphysema: The MESA COPD Study

Unsupervised discovery of pulmonary emphysema subtypes offers the potential for new definitions of emphysema on lung computed tomography (CT) that go beyond the standard subtypes identified on autopsy. Emphysema subtypes can be defined on CT as a variety of textures with certain spatial prevalence. However, most existing approaches for learning emphysema subtypes on CT are limited to texture features, which are sub-optimal due to the lack of spatial information. In this work, we exploit a standardized spatial mapping of the lung and propose a novel framework for combining spatial and texture information to discover spatially-informed lung texture patterns (sLTPs). Our spatial mapping is demonstrated to be a powerful tool to study emphysema spatial locations over different populations. The discovered sLTPs are shown to have high reproducibility, ability to encode standard emphysema subtypes, and significant associations with clinical characteristics.

Explaining Radiological Emphysema Subtypes with Unsupervised Texture Prototypes: MESA COPD Study

Pulmonary emphysema is traditionally subcategorized into three subtypes, which have distinct radiological appearances on computed tomography (CT) and can help with the diagnosis of chronic obstructive pulmonary disease (COPD). Automated texture-based quantification of emphysema subtypes has been successfully implemented via supervised learning of these three emphysema subtypes. In this work, we demonstrate that unsupervised learning on a large heterogeneous database of CT scans can generate texture prototypes that are visually homogeneous and distinct, reproducible across subjects, and capable of predicting accurately the three standard radiological subtypes. These texture prototypes enable automated labeling of lung volumes, and open the way to new interpretations of lung CT scans with finer subtyping of emphysema.

Lung function, percent emphysema, and QT duration: The Multi-Ethnic Study of Atherosclerosis (MESA) lung study

BACKGROUND

The QT interval on electrocardiogram (ECG) reflects ventricular repolarization; a prolonged QT interval is associated with increased mortality risk. Prior studies suggest an association between chronic obstructive pulmonary disease (COPD) and prolonged QT interval. However, these studies were small and often enrolled hospital-based samples. We tested the hypotheses that lower lung function and increased percent emphysema on computed tomography (CT) are associated with a prolonged QT interval in a general population sample and additionally in those with COPD.

METHODS

As part of the Multi-Ethnic Study of Atherosclerosis (MESA) Lung Study, we assessed spirometry, full-lung CT scans, and ECGs in participants aged 45-84 years. The QT on ECGs was corrected for heart rate (QTc) using the Framingham formula. QTc values = 460 msec in women and ≥450 msec in men were considered abnormal (prolonged QT_C). Multivariate regression models were used to examine the cross-sectional association between pulmonary measures and QT_C. RESULTS: The mean age of the sample of 2585 participants was 69 years, and 47% were men. There was an inverse association between FEV₁%, FVC%, FEV₁/FVC%, emphysema, QTc duration and prolonged QTc. Gender was a significant interaction term, even among never smokers. Having severe COPD was also associated with QTc prolongation.

CONCLUSIONS

Our analysis revealed a significant association between lower lung function and longer QTc in men but not in women in a population-based sample. Our findings suggest the possibility of gender differences in the risk of QTc-associated arrhythmias in a population-based sample.

Percent Emphysema and Daily Motor Activity Levels in the General Population: Multi-Ethnic Study of Atherosclerosis

BACKGROUND

COPD is associated with reduced physical capacity. However, it is unclear whether pulmonary emphysema, which can occur without COPD, is associated with reduced physical activity in daily life, particularly among people without COPD and never smokers. We hypothesized that greater percentage of emphysema-like lung on CT scan is associated with reduced physical activity assessed by actigraphy and self-report.

METHODS

The Multi-Ethnic Study of Atherosclerosis (MESA) enrolled participants free of clinical cardiovascular disease from the general population. Percent emphysema was defined as percentage of voxels < -950 Hounsfield units on full-lung CT scans. Physical activity was measured by wrist actigraphy over 7 days and a questionnaire. Multivariable linear regression was used to adjust for age, sex, race/ethnicity, height, weight, education, smoking, pack-years, and lung function.

RESULTS

Among 1,435 participants with actigraphy and lung measures, 47% had never smoked, and 8% had COPD. Percent emphysema was associated with lower activity levels on actigraphy (P = .001), corresponding to 1.5 hour less per week of moderately paced walking for the average participant in quintile 2 vs 4 of percent emphysema. This association was significant among participants without COPD (P = .004) and among ever (P = .01) and never smokers (P = .03). It was also independent of coronary artery calcium and left ventricular ejection fraction. There was no evidence that percent emphysema was associated with self-reported activity levels.

CONCLUSIONS

Percent emphysema was associated with decreased physical activity in daily life objectively assessed by actigraphy in the general population, among participants without COPD, and nonsmokers.

Rheumatoid arthritis-associated autoantibodies and subclinical interstitial lung disease: the Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Adults with interstitial lung disease (ILD) often have serologic evidence of autoimmunity of uncertain significance without overt autoimmune disease. We examined associations of rheumatoid arthritis (RA)-associated antibodies with subclinical ILD in community-dwelling adults.

METHODS

We measured serum rheumatoid factor (RF) and anticyclic citrullinated peptide antibody (anti-CCP) and high attenuation areas (HAAs; CT attenuation values between -600 and -250 Hounsfield units) on cardiac CT in 6736 community-dwelling US adults enrolled in the Multi-Ethnic Study of Atherosclerosis. We measured interstitial lung abnormalities (ILAs) in 2907 full-lung CTs at 9.5-year median follow-up. We used generalised linear and additive models to examine associations between autoantibodies and both HAA and ILA, and tested for effect modification by smoking.

RESULTS

In adjusted models, HAA increased by 0.49% (95% CI 0.11% to 0.86%) per doubling of RF IgM and by 0.95% (95% CI 0.50% to 1.40%) per RF IgA doubling. ILA prevalence increased by 11% (95% CI 3% to 20%) per RF IgA doubling. Smoking modified the associations of both RF IgM and anti-CCP with both HAA and ILA (interaction p values varied from 0.01 to 0.09). Among ever smokers, HAA increased by 0.81% (95% CI 0.33% to 1.30%) and ILA prevalence increased by 14% (95% CI 5% to 24%,) per RF IgM doubling; and HAA increased by 1.31% (95% CI 0.45% to 2.18%) and ILA prevalence increased by 13% (95% CI 2% to 24%) per anti-CCP doubling. Among never smokers, no meaningful associations were detected.

CONCLUSIONS

RA-related autoimmunity is associated with both quantitative and qualitative subclinical ILD phenotypes on CT, particularly among ever smokers.

High attenuation areas on chest computed tomography in community-dwelling adults: the MESA study

Evidence suggests that lung injury, inflammation and extracellular matrix remodelling precede lung fibrosis in interstitial lung disease (ILD). We examined whether a quantitative measure of increased lung attenuation on computed tomography (CT) detects lung injury, inflammation and extracellular matrix remodelling in community-dwelling adults sampled without regard to respiratory symptoms or smoking.We measured high attenuation areas (HAA; percentage of lung voxels between -600 and -250 Hounsfield Units) on cardiac CT scans of adults enrolled in the Multi-Ethnic Study of Atherosclerosis.HAA was associated with higher serum matrix metalloproteinase-7 (mean adjusted difference 6.3% per HAA doubling, 95% CI 1.3-11.5), higher interleukin-6 (mean adjusted difference 8.8%, 95% CI 4.8-13.0), lower forced vital capacity (FVC) (mean adjusted difference -82 mL, 95% CI -119--44), lower 6-min walk distance (mean adjusted difference -40 m, 95% CI -1--80), higher odds of interstitial lung abnormalities at 9.5 years (adjusted OR 1.95, 95% CI 1.43-2.65), and higher all cause-mortality rate over 12.2 years (HR 1.58, 95% CI 1.39-1.79).High attenuation areas are associated with biomarkers of inflammation and extracellular matrix remodelling, reduced lung function, interstitial lung abnormalities, and a higher risk of death among community-dwelling adults.

Cancer Outcomes at the Hufeland (Complementary/Alternative Medicine) Klinik: A Best-Case Series Review

Purpose: A best-case series review is an efficient tool with which to screen complex complementary and alternative treatments for cancer as candidates for further study. Study Design: The National Cancer Institute and other agencies have adopted the best-case series method to evaluate cancer treatments involving complementary and alternative medicine (CAM) for further study. The authors conducted a best-case series review of the Hufeland Klinik. Established in 1985 in Bad Mergentheim, Germany, this facility treats more than 500 cancer patients per year. Hufeland treatment includes dietary modification, injections, ozone therapy, active fever therapy, psychotherapy, and sometimes hormone therapy and/or low-dose chemotherapy. The goal of the treatment is to prolong survival and to maintain good quality of life. Methods: The clinic provided summaries of 27 cases in which patients with longer than expected survival had agreed to make their medical records available for review. The review involved pathologic confirmation of disease and radiologic confirmation of complete response (CR) or partial response (PR) not attributable to conventional treatment. Results: Based on the summaries and an exhaustive 2-year search for medical records, slides, and imaging data, 12 of 27 cases were selected for full review, and 5 (3 CRs and 2 PRs) were judged best cases. Conclusion: Most patients with common cancers receive conventional treatment before coming to Hufeland, and many are treated with chemotherapy and/or hormonal therapy while there. Hence, only a few could be considered for review. With 5 of 12 patients showing a treatment response, the authors conclude that the Hufeland treatment merits further study. They also recommend the development of criteria with which to evaluate best-case series reviews of complex CAM treatments for patients with advanced cancer.

Pulmonary Microvascular Blood Flow in Mild Chronic Obstructive Pulmonary Disease and Emphysema. The MESA COPD Study

RATIONALE

Smoking-related microvascular loss causes end-organ damage in the kidneys, heart, and brain. Basic research suggests a similar process in the lungs, but no large studies have assessed pulmonary microvascular blood flow (PMBF) in early chronic lung disease.

OBJECTIVES

To investigate whether PMBF is reduced in mild as well as more severe chronic obstructive pulmonary disease (COPD) and emphysema.

METHODS

PMBF was measured using gadolinium-enhanced magnetic resonance imaging (MRI) among smokers with COPD and control subjects age 50 to 79 years without clinical cardiovascular disease. COPD severity was defined by standard criteria. Emphysema on computed tomography (CT) was defined by the percentage of lung regions below -950 Hounsfield units (-950 HU) and by radiologists using a standard protocol. We adjusted for potential confounders, including smoking, oxygenation, and left ventricular cardiac output.

MEASUREMENTS AND MAIN RESULTS

Among 144 participants, PMBF was reduced by 30% in mild COPD, by 29% in moderate COPD, and by 52% in severe COPD (all P < 0.01 vs. control subjects). PMBF was reduced with greater percentage emphysema-950HU and radiologist-defined emphysema, particularly panlobular and centrilobular emphysema (all P ≤ 0.01). Registration of MRI and CT images revealed that PMBF was reduced in mild COPD in both nonemphysematous and emphysematous lung regions. Associations for PMBF were independent of measures of small airways disease on CT and gas trapping largely because emphysema and small airways disease occurred in different smokers.

CONCLUSIONS

PMBF was reduced in mild COPD, including in regions of lung without frank emphysema, and may represent a distinct pathological process from small airways disease. PMBF may provide an imaging biomarker for therapeutic strategies targeting the pulmonary microvasculature.

Clinical and Radiologic Disease in Smokers With Normal Spirometry

IMPORTANCE

Airflow obstruction on spirometry is universally used to define chronic obstructive pulmonary disease (COPD), and current or former smokers without airflow obstruction may assume that they are disease free.

OBJECTIVE

To identify clinical and radiologic evidence of smoking-related disease in a cohort of current and former smokers who did not meet spirometric criteria for COPD, for whom we adopted the discarded label of Global Initiative for Obstructive Lung Disease (GOLD) 0.

DESIGN, SETTING, AND PARTICIPANTS

Individuals from the Genetic Epidemiology of COPD (COPDGene) cross-sectional observational study completed spirometry, chest computed tomography (CT) scans, a 6-minute walk, and questionnaires. Participants were recruited from local communities at 21 sites across the United States. The GOLD 0 group (n = 4388) (ratio of forced expiratory volume in the first second of expiration [FEV1] to forced vital capacity >0.7 and FEV1 ≥80% predicted) from the COPDGene study was compared with a GOLD 1 group (n = 794), COPD groups (n = 3690), and a group of never smokers (n = 108). Recruitment began in January 2008 and ended in July 2011.

MAIN OUTCOMES AND MEASURES

Physical function impairments, respiratory symptoms, CT abnormalities, use of respiratory medications, and reduced respiratory-specific quality of life.

RESULTS

One or more respiratory-related impairments were found in 54.1% (2375 of 4388) of the GOLD 0 group. The GOLD 0 group had worse quality of life (mean [SD] St George's Respiratory Questionnaire total score, 17.0 [18.0] vs 3.8 [6.8] for the never smokers; P < .001) and a lower 6-minute walk distance, and 42.3% (127 of 300) of the GOLD 0 group had CT evidence of emphysema or airway thickening. The FEV1 percent predicted distribution and mean for the GOLD 0 group were lower but still within the normal range for the population. Current smoking was associated with more respiratory symptoms, but former smokers had greater emphysema and gas trapping. Advancing age was associated with smoking cessation and with more CT findings of disease. Individuals with respiratory impairments were more likely to use respiratory medications, and the use of these medications was associated with worse disease.

CONCLUSIONS AND RELEVANCE

Lung disease and impairments were common in smokers without spirometric COPD. Based on these results, we project that there are 35 million current and former smokers older than 55 years in the United States who may have unrecognized disease or impairment. The effect of chronic smoking on the lungs and the individual is substantially underestimated when using spirometry alone.

CT-Definable Subtypes of Chronic Obstructive Pulmonary Disease: A Statement of the Fleischner Society

The purpose of this statement is to describe and define the phenotypic abnormalities that can be identified on visual and quantitative evaluation of computed tomographic (CT) images in subjects with chronic obstructive pulmonary disease (COPD), with the goal of contributing to a personalized approach to the treatment of patients with COPD. Quantitative CT is useful for identifying and sequentially evaluating the extent of emphysematous lung destruction, changes in airway walls, and expiratory air trapping. However, visual assessment of CT scans remains important to describe patterns of altered lung structure in COPD. The classification system proposed and illustrated in this article provides a structured approach to visual and quantitative assessment of COPD. Emphysema is classified as centrilobular (subclassified as trace, mild, moderate, confluent, and advanced destructive emphysema), panlobular, and paraseptal (subclassified as mild or substantial). Additional important visual features include airway wall thickening, inflammatory small airways disease, tracheal abnormalities, interstitial lung abnormalities, pulmonary arterial enlargement, and bronchiectasis.

Cor pulmonale parvus in chronic obstructive pulmonary disease and emphysema: the MESA COPD study

BACKGROUND

The classic cardiovascular complication of chronic obstructive pulmonary disease (COPD) is cor pulmonale or right ventricular (RV) enlargement. Most studies of cor pulmonale were conducted decades ago.

OBJECTIVES

This study sought to examine RV changes in contemporary COPD and emphysema using cardiac magnetic resonance (CMR) imaging.

METHODS

We performed a case-control study nested predominantly in 2 general population studies of 310 participants with COPD and control subjects 50 to 79 years of age with ≥10 pack-years of smoking who were free of clinical cardiovascular disease. RV volumes and mass were assessed using magnetic resonance imaging. COPD and COPD severity were defined according to standard spirometric criteria. The percentage of emphysema was defined as the percentage of lung regions <-950 Hounsfield units on full-lung computed tomography; emphysema subtypes were scored by radiologists. Results were adjusted for age, race/ethnicity, sex, height, weight, smoking status, pack-years, systemic hypertension, and sleep apnea.

RESULTS

Right ventricular end-diastolic volume (RVEDV) was reduced in COPD compared with control subjects (-7.8 ml; 95% confidence interval: -15.0 to -0.5 ml; p = 0.04). Increasing severity of COPD was associated with lower RVEDV (p = 0.004) and lower RV stroke volume (p < 0.001). RV mass and ejection fraction were similar between the groups. A greater percentage of emphysema also was associated with lower RVEDV (p = 0.005) and stroke volume (p < 0.001), as was the presence of centrilobular and paraseptal emphysema.

CONCLUSIONS

RV volumes are lower without significant alterations in RV mass and ejection fraction in contemporary COPD, and this reduction is related to the greater percentage of emphysema on computed tomography.

Intercellular adhesion molecule 1 and progression of percent emphysema: the MESA Lung Study

BACKGROUND

Endothelial intercellular adhesion molecule (ICAM) 1 binds neutrophils and facilitates their transmigration into the lung; E-selectin facilitates leukocyte rolling. As neutrophils contribute to tissue destruction in emphysema and chronic obstructive pulmonary disease, we hypothesized that soluble ICAM-1 (sICAM-1) and E-selectin (sE-selectin) would be associated with longitudinal progression of emphysema and lung function decline.

METHODS

The Multi-Ethnic Study of Atherosclerosis (MESA) enrolled participants 45-84 years old without clinical cardiovascular disease in 2000-02. The MESA Lung Study assessed percent emphysema (<-950 Hounsfield units) on cardiac (2000-07) and full-lung CT scans (2010-12), and spirometry was assessed twice over five years. sICAM-1 and sE-selectin were measured at baseline. Mixed-effect models adjusted for demographics, anthropometry, smoking, C-reactive protein, sphingomyelin and scanner factors.

RESULTS

Among 1865 MESA Lung participants with measurement of sICAM-1 and percent emphysema the mean log-sICAM-1 was 5.5 ± 0.3 ng/mL and percent emphysema increased 0.73 percentage points (95% CI: 0.34, 1.12; P < 0.001) over ten years. A one SD increase in sICAM-1 was associated with an accelerated increase in percent emphysema of 0.23 percentage points over ten years (95% CI: 0.06, 0.39; P = 0.007). No significant association was found for sE-selectin, or between any adhesion molecule and lung function.

CONCLUSIONS

Higher levels of sICAM-1 were independently associated with progression of percent emphysema in a general population sample.

Emphysema predicts hospitalisation and incident airflow obstruction among older smokers: a prospective cohort study

BACKGROUND

Emphysema on CT is common in older smokers. We hypothesised that emphysema on CT predicts acute episodes of care for chronic lower respiratory disease among older smokers.

MATERIALS AND METHODS

Participants in a lung cancer screening study age ≥ 60 years were recruited into a prospective cohort study in 2001-02. Two radiologists independently visually assessed the severity of emphysema as absent, mild, moderate or severe. Percent emphysema was defined as the proportion of voxels ≤ -910 Hounsfield Units. Participants completed a median of 5 visits over a median of 6 years of follow-up. The primary outcome was hospitalization, emergency room or urgent office visit for chronic lower respiratory disease. Spirometry was performed following ATS/ERS guidelines. Airflow obstruction was defined as FEV1/FVC ratio <0.70 and FEV1<80% predicted.

RESULTS

Of 521 participants, 4% had moderate or severe emphysema, which was associated with acute episodes of care (rate ratio 1.89; 95% CI: 1.01-3.52) adjusting for age, sex and race/ethnicity, as was percent emphysema, with similar associations for hospitalisation. Emphysema on visual assessment also predicted incident airflow obstruction (HR 5.14; 95% CI 2.19-21.1).

CONCLUSION

Visually assessed emphysema and percent emphysema on CT predicted acute episodes of care for chronic lower respiratory disease, with the former predicting incident airflow obstruction among older smokers.

Genome-wide study of percent emphysema on computed tomography in the general population. The Multi-Ethnic Study of Atherosclerosis Lung/SNP Health Association Resource Study

RATIONALE

Pulmonary emphysema overlaps partially with spirometrically defined chronic obstructive pulmonary disease and is heritable, with moderately high familial clustering.

OBJECTIVES

To complete a genome-wide association study (GWAS) for the percentage of emphysema-like lung on computed tomography in the Multi-Ethnic Study of Atherosclerosis (MESA) Lung/SNP Health Association Resource (SHARe) Study, a large, population-based cohort in the United States.

METHODS

We determined percent emphysema and upper-lower lobe ratio in emphysema defined by lung regions less than -950 HU on cardiac scans. Genetic analyses were reported combined across four race/ethnic groups: non-Hispanic white (n = 2,587), African American (n = 2,510), Hispanic (n = 2,113), and Chinese (n = 704) and stratified by race and ethnicity.

MEASUREMENTS AND MAIN RESULTS

Among 7,914 participants, we identified regions at genome-wide significance for percent emphysema in or near SNRPF (rs7957346; P = 2.2 × 10(-8)) and PPT2 (rs10947233; P = 3.2 × 10(-8)), both of which replicated in an additional 6,023 individuals of European ancestry. Both single-nucleotide polymorphisms were previously implicated as genes influencing lung function, and analyses including lung function revealed independent associations for percent emphysema. Among Hispanics, we identified a genetic locus for upper-lower lobe ratio near the α-mannosidase-related gene MAN2B1 (rs10411619; P = 1.1 × 10(-9); minor allele frequency [MAF], 4.4%). Among Chinese, we identified single-nucleotide polymorphisms associated with upper-lower lobe ratio near DHX15 (rs7698250; P = 1.8 × 10(-10); MAF, 2.7%) and MGAT5B (rs7221059; P = 2.7 × 10(-8); MAF, 2.6%), which acts on α-linked mannose. Among African Americans, a locus near a third α-mannosidase-related gene, MAN1C1 (rs12130495; P = 9.9 × 10(-6); MAF, 13.3%) was associated with percent emphysema.

CONCLUSIONS

Our results suggest that some genes previously identified as influencing lung function are independently associated with emphysema rather than lung function, and that genes related to α-mannosidase may influence risk of emphysema.

Pulmonary emphysema subtypes on computed tomography: the MESA COPD study

BACKGROUND

Pulmonary emphysema is divided into 3 major subtypes at autopsy: centrilobular, paraseptal, and panlobular emphysema. These subtypes can be defined by visual assessment on computed tomography (CT); however, clinical characteristics of emphysema subtypes on CT are not well defined. We developed a reliable approach to visual assessment of emphysema subtypes on CT and examined if emphysema subtypes have distinct characteristics.

METHODS

The Multi-Ethnic Study of Atherosclerosis COPD Study recruited smokers with chronic obstructive pulmonary disease (COPD) and controls ages 50-79 years with ≥ 10 pack-years. Participants underwent CT following a standardized protocol. Definitions of centrilobular, paraseptal, and panlobular emphysema were obtained by literature review. Six-minute walk distance and pulmonary function were performed following guidelines.

RESULTS

Twenty-seven percent of 318 smokers had emphysema on CT. Interrater reliability of emphysema subtype was substantial (K: 0.70). Compared with participants without emphysema, individuals with centrilobular or panlobular emphysema had greater dyspnea, reduced walk distance, greater hyperinflation, and lower diffusing capacity. In contrast, individuals with paraseptal emphysema were similar to controls, except for male predominance. Centrilobular, but not panlobular or paraseptal, emphysema was associated with greater smoking history (+21 pack-years P <.001). Panlobular, but not other types of emphysema, was associated with reduced body mass index (-5 kg/m(2); P = .01). Other than for dyspnea, these findings were independent of the forced expiratory volume in 1 second. Seventeen percent of smokers without COPD on spirometry had emphysema, which was independently associated with reduced walk distance.

CONCLUSIONS

Emphysema subtypes on CT are common in smokers with and without COPD. Centrilobular and panlobular emphysema, but not paraseptal emphysema, have considerable symptomatic and physiological consequences.

Bronchial thermoplasty: Long-term safety and effectiveness in patients with severe persistent asthma

BACKGROUND

Bronchial thermoplasty (BT) has previously been shown to improve asthma control out to 2 years in patients with severe persistent asthma.

OBJECTIVE

We sought to assess the effectiveness and safety of BT in asthmatic patients 5 years after therapy.

METHODS

BT-treated subjects from the Asthma Intervention Research 2 trial (ClinicalTrials.govNCT01350414) were evaluated annually for 5 years to assess the long-term safety of BT and the durability of its treatment effect. Outcomes assessed after BT included severe exacerbations, adverse events, health care use, spirometric data, and high-resolution computed tomographic scans.

RESULTS

One hundred sixty-two (85.3%) of 190 BT-treated subjects from the Asthma Intervention Research 2 trial completed 5 years of follow-up. The proportion of subjects experiencing severe exacerbations and emergency department (ED) visits and the rates of events in each of years 1 to 5 remained low and were less than those observed in the 12 months before BT treatment (average 5-year reduction in proportions: 44% for exacerbations and 78% for ED visits). Respiratory adverse events and respiratory-related hospitalizations remained unchanged in years 2 through 5 compared with the first year after BT. Prebronchodilator FEV₁ values remained stable between years 1 and 5 after BT, despite a 18% reduction in average daily inhaled corticosteroid dose. High-resolution computed tomographic scans from baseline to 5 years after BT showed no structural abnormalities that could be attributed to BT.

CONCLUSIONS

These data demonstrate the 5-year durability of the benefits of BT with regard to both asthma control (based on maintained reduction in severe exacerbations and ED visits for respiratory symptoms) and safety. BT has become an important addition to our treatment armamentarium and should be considered for patients with severe persistent asthma who remain symptomatic despite taking inhaled corticosteroids and long-acting β₂-agonists.

Radiologic implications of the 2011 classification of adenocarcinoma of the lung

Now the leading subtype of lung cancer, adenocarcinoma received a new classification in 2011. For tumors categorized previously as bronchioloalveolar carcinoma (BAC), criteria and terminology had not been uniform, so the 2011 classification provided four new terms: (a) adenocarcinoma in situ (AIS), representing histopathologically a small (≤3-cm), noninvasive lepidic growth, which at computed tomography (CT) is usually nonsolid; (b) minimally invasive adenocarcinoma, representing histopathologically a small (≤3-cm) and predominantly lepidic growth that has 5-mm or smaller invasion, which at CT is mainly nonsolid but may have a central solid component of up to approximately 5 mm; (c) lepidic predominant nonmucinous adenocarcinoma, representing histopathologically invasive adenocarcinoma that shows predominantly lepidic nonmucinous growth, which at CT is usually part solid but may be nonsolid or occasionally have cystic components; and (d) invasive mucinous adenocarcinoma, histopathologically showing lepidic growth as its predominant component, which at CT varies widely from solid to mostly solid to part solid to nonsolid and may be single or multiple (when multifocal, it was formerly called multicentric BAC). In addition, new histopathologic subcategories of acinar, papillary, micropapillary, and solid predominant adenocarcinoma are now described, all as nonmucinous, predominantly invasive, may include a small lepidic component, and at CT are usually solid but may include a small nonsolid component. The micropapillary subtype has a poorer prognosis than the other subtypes. In addition, molecular genetic correlations for the subcategories of adenocarcinoma of the lung are now a topic of increasing interest. As the new classification enters common use, further descriptions of related correlations can be anticipated.

The American Association for Thoracic Surgery guidelines for lung cancer screening using low-dose computed tomography scans for lung cancer survivors and other high-risk groups

OBJECTIVE

Lung cancer is the leading cause of cancer death in North America. Low-dose computed tomography screening can reduce lung cancer-specific mortality by 20%.

METHOD

The American Association for Thoracic Surgery created a multispecialty task force to create screening guidelines for groups at high risk of developing lung cancer and survivors of previous lung cancer.

RESULTS

The American Association for Thoracic Surgery guidelines call for annual lung cancer screening with low-dose computed tomography screening for North Americans from age 55 to 79 years with a 30 pack-year history of smoking. Long-term lung cancer survivors should have annual low-dose computed tomography to detect second primary lung cancer until the age of 79 years. Annual low-dose computed tomography lung cancer screening should be offered starting at age 50 years with a 20 pack-year history if there is an additional cumulative risk of developing lung cancer of 5% or greater over the following 5 years. Lung cancer screening requires participation by a subspecialty-qualified team. The American Association for Thoracic Surgery will continue engagement with other specialty societies to refine future screening guidelines.

CONCLUSIONS

The American Association for Thoracic Surgery provides specific guidelines for lung cancer screening in North America.

Development of The American Association for Thoracic Surgery guidelines for low-dose computed tomography scans to screen for lung cancer in North America: recommendations of The American Association for Thoracic Surgery Task Force for Lung Cancer Screening and Surveillance

OBJECTIVE

The study objective was to establish The American Association for Thoracic Surgery (AATS) lung cancer screening guidelines for clinical practice.

METHODS

The AATS established the Lung Cancer Screening and Surveillance Task Force with multidisciplinary representation including 4 thoracic surgeons, 4 thoracic radiologists, 4 medical oncologists, 1 pulmonologist, 1 pathologist, and 1 epidemiologist. Members have engaged in interdisciplinary collaborations regarding lung cancer screening and clinical care of patients with, and at risk for, lung cancer. The task force reviewed the literature, including screening trials in the United States and Europe, and discussed local best clinical practices in the United States and Canada on 4 conference calls. A reference library supported the discussions and increased individual study across disciplines. The task force met to review the literature, state of clinical practice, and recommend consensus-based guidelines.

RESULTS

Nine of 14 task force members were present at the meeting, and 3 participated by telephone. Two absent task force members were polled afterward. Six unanimous recommendations and supporting work-up algorithms were presented to the Council of the AATS at the 2012 annual meeting in San Francisco, California.

CONCLUSIONS

Annual lung cancer screening and surveillance with low-dose computed tomography is recommended for smokers and former smokers with a 30 pack-year history of smoking and long-term lung cancer survivors aged 55 to 79 years. Screening may begin at age 50 years with a 20 pack-year history of smoking and additional comorbidity that produces a cumulative risk of developing lung cancer of 5% or greater over the following 5 years. Screening should be undertaken with a subspecialty qualified interdisciplinary team. Patient risk calculator application and intersociety engagement will provide data needed to refine future lung cancer screening guidelines.

International association for the study of lung cancer/american thoracic society/european respiratory society international multidisciplinary classification of lung adenocarcinoma

INTRODUCTION

Adenocarcinoma is the most common histologic type of lung cancer. To address advances in oncology, molecular biology, pathology, radiology, and surgery of lung adenocarcinoma, an international multidisciplinary classification was sponsored by the International Association for the Study of Lung Cancer, American Thoracic Society, and European Respiratory Society. This new adenocarcinoma classification is needed to provide uniform terminology and diagnostic criteria, especially for bronchioloalveolar carcinoma (BAC), the overall approach to small nonresection cancer specimens, and for multidisciplinary strategic management of tissue for molecular and immunohistochemical studies.

METHODS

An international core panel of experts representing all three societies was formed with oncologists/pulmonologists, pathologists, radiologists, molecular biologists, and thoracic surgeons. A systematic review was performed under the guidance of the American Thoracic Society Documents Development and Implementation Committee. The search strategy identified 11,368 citations of which 312 articles met specified eligibility criteria and were retrieved for full text review. A series of meetings were held to discuss the development of the new classification, to develop the recommendations, and to write the current document. Recommendations for key questions were graded by strength and quality of the evidence according to the Grades of Recommendation, Assessment, Development, and Evaluation approach.

RESULTS

The classification addresses both resection specimens, and small biopsies and cytology. The terms BAC and mixed subtype adenocarcinoma are no longer used. For resection specimens, new concepts are introduced such as adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) for small solitary adenocarcinomas with either pure lepidic growth (AIS) or predominant lepidic growth with ≤ 5 mm invasion (MIA) to define patients who, if they undergo complete resection, will have 100% or near 100% disease-specific survival, respectively. AIS and MIA are usually nonmucinous but rarely may be mucinous. Invasive adenocarcinomas are classified by predominant pattern after using comprehensive histologic subtyping with lepidic (formerly most mixed subtype tumors with nonmucinous BAC), acinar, papillary, and solid patterns; micropapillary is added as a new histologic subtype. Variants include invasive mucinous adenocarcinoma (formerly mucinous BAC), colloid, fetal, and enteric adenocarcinoma. This classification provides guidance for small biopsies and cytology specimens, as approximately 70% of lung cancers are diagnosed in such samples. Non-small cell lung carcinomas (NSCLCs), in patients with advanced-stage disease, are to be classified into more specific types such as adenocarcinoma or squamous cell carcinoma, whenever possible for several reasons: (1) adenocarcinoma or NSCLC not otherwise specified should be tested for epidermal growth factor receptor (EGFR) mutations as the presence of these mutations is predictive of responsiveness to EGFR tyrosine kinase inhibitors, (2) adenocarcinoma histology is a strong predictor for improved outcome with pemetrexed therapy compared with squamous cell carcinoma, and (3) potential life-threatening hemorrhage may occur in patients with squamous cell carcinoma who receive bevacizumab. If the tumor cannot be classified based on light microscopy alone, special studies such as immunohistochemistry and/or mucin stains should be applied to classify the tumor further. Use of the term NSCLC not otherwise specified should be minimized.

CONCLUSIONS

This new classification strategy is based on a multidisciplinary approach to diagnosis of lung adenocarcinoma that incorporates clinical, molecular, radiologic, and surgical issues, but it is primarily based on histology. This classification is intended to support clinical practice, and research investigation and clinical trials. As EGFR mutation is a validated predictive marker for response and progression-free survival with EGFR tyrosine kinase inhibitors in advanced lung adenocarcinoma, we recommend that patients with advanced adenocarcinomas be tested for EGFR mutation. This has implications for strategic management of tissue, particularly for small biopsies and cytology samples, to maximize high-quality tissue available for molecular studies. Potential impact for tumor, node, and metastasis staging include adjustment of the size T factor according to only the invasive component (1) pathologically in invasive tumors with lepidic areas or (2) radiologically by measuring the solid component of part-solid nodules.

Cigarette smoking is associated with subclinical parenchymal lung disease: the Multi-Ethnic Study of Atherosclerosis (MESA)-lung study

RATIONALE

Cigarette smoking is a risk factor for diffuse parenchymal lung disease. Risk factors for subclinical parenchymal lung disease have not been described.

OBJECTIVES

To determine if cigarette smoking is associated with subclinical parenchymal lung disease, as measured by spirometric restriction and regions of high attenuation on computed tomography (CT) imaging.

METHODS

We examined 2,563 adults without airflow obstruction or clinical cardiovascular disease in the Multi-Ethnic Study of Atherosclerosis, a population-based cohort sampled from six communities in the United States. Cumulative and current cigarette smoking were assessed by pack-years and urine cotinine, respectively. Spirometric restriction was defined as a forced vital capacity less than the lower limit of normal. High attenuation areas on the lung fields of cardiac CT scans were defined as regions having an attenuation between -600 and -250 Hounsfield units, reflecting ground-glass and reticular abnormalities. Generalized additive models were used to adjust for age, gender, race/ethnicity, smoking status, anthropometrics, center, and CT scan parameters.

MEASUREMENTS AND MAIN RESULTS

The prevalence of spirometric restriction was 10.0% (95% confidence interval [CI], 8.9-11.2%) and increased relatively by 8% (95% CI, 3-12%) for each 10 cigarette pack-years in multivariate analysis. The median volume of high attenuation areas was 119 cm(3) (interquartile range, 100-143 cm(3)). The volume of high attenuation areas increased by 1.6 cm(3) (95% CI, 0.9-2.4 cm(3)) for each 10 cigarette pack-years in multivariate analysis.

CONCLUSIONS

Smoking may cause subclinical parenchymal lung disease detectable by spirometry and CT imaging, even among a generally healthy cohort.

Pulmonary lymphoma identified as a result of low-dose CT screening for lung cancer

PURPOSE

To describe the frequency and findings of pulmonary lymphoma in asymptomatic people undergoing computed tomographic (CT) screening for lung cancer.

METHODS

All lymphoma diagnoses resulting from CT screening of 31 567 at-risk subjects (median age, 61 years) were identified, and the CT images were reviewed to document the lesions as to number, location, density, shape, and margin. The presence of lymphadenopathy and pleural effusion was also documented.

RESULTS

Five patients with pulmonary lymphoma were identified. The lymphoma was a B-cell lymphoma in three, Hodgkin's lymphoma in one, and malignant lymphoma in one; it was primary in four and secondary in one. One patient had two lesions; the other four patients each had one lesion. Four of the six lesions were a mass, and two were a nodule. Four of the lesions had irregular margins. Air bronchograms were seen in three. Growth assessment was useful in leading to decisions for biopsy.

CONCLUSION

In a context of CT screening to detect lung cancer in asymptomatic volunteers, the diagnosis of pulmonary lymphoma was rare but, nevertheless, occurred in five (.016%) of 31 567 volunteers.

Plasma carbonyls do not correlate with lung function or computed tomography measures of lung density in older smokers

Oxidative stress and inflammation are hallmarks of chronic obstructive pulmonary disease (COPD). A critical byproduct of oxidative damage is the introduction of carbonyl groups into amino acid residues. We hypothesize that plasma carbonyl content is inversely correlated with lung function and computed tomography (CT) measures of lung density among smokers and is elevated in COPD. Carbonyl was measured in plasma of participants aged 60 years and older by ELISA. Generalized linear and additive models were used to adjust for potential confounders. Among 541 participants (52% male, mean age 67 years, 41% current smokers), mean plasma carbonyl content was 17.9+/-2.9 nmol ml(-1) and mean forced expiratory volume in one second (FEV(1)) was 80.7+/-20.9% of predicted. Plasma carbonyl content was inversely associated with FEV(1), but this relationship was largely explained by age. Multivariate analyses ruled out clinically meaningful associations of plasma carbonyl content with FEV(1), FEV(1)/FVC (forced vital capacity) ratio, severity of airflow obstruction, and CT lung density. Plasma carbonyl content is a poor biomarker of oxidative stress in COPD and emphysema.

No effect of cigarette smoking dose on oxidized plasma proteins

Cigarette smoking is a major source of oxidative stress. Protein carbonyls have been used as a biomarker of oxidative stress because of the relative stability of carbonylated proteins and the high protein concentration in blood. Increased levels of carbonyl groups have been found in serum proteins of smokers compared to nonsmokers. However, neither the dose effect of current cigarette smoke nor other predictors of oxidative stress have been studied. Hence, we used an Enzyme-Linked Immunosorbent Assay (ELISA) to evaluate plasma protein carbonyls in smokers recruited in the Early Lung Cancer Action Project (ELCAP) program. The lung cancer screening program enrolled current and former smokers age 60 years and over without a prior cancer diagnosis. A total of 542 participants (282 men and 260 women) completed a baseline questionnaire and provided blood samples for the biomarker study. Protein oxidation was measured by derivatization of the carbonyl groups with 2,4-dinitrophenylhydrazine (DNPH) and ELISA quantitation of the DNPH group. Current smoking status was confirmed with urinary cotinine. The mean (+/-S.D.) protein carbonyl level was 17.9+/-2.9 nmol carbonyl/ml plasma. Protein carbonyls did not differ significantly by gender. Carbonyl levels were higher among current than former smokers, but these differences did not attain statistical significance, nor did differences by urine cotinine levels, pack-years, pack/day among current smokers, and smoking duration. In a multiple regression analysis, higher protein carbonyl levels were independently associated with increasing age (0.59 nmol/ml increase per 10 years, 95% CI 0.14, 1.05, p=0.01), African-American vs. white race/ethnicity, (1.30 nmol/ml, 95% CI 0.4, 2.19, p=0.008), and lower educational attainment (0.75 nmol/ml, 95% CI 0.12, 1.38, p=0.02). Although we found no significant difference between current vs. past cigarette smoking and protein carbonyls in this older group of smokers, associations were found for age, ethnicity, and educational attainment. Our results indicate that the measurement of plasma carbonyls by this ELISA technique is still an easy and suitable method for studies of diseases related to oxidative stress.

Impaired flow-mediated dilation is associated with low pulmonary function and emphysema in ex-smokers: the Emphysema and Cancer Action Project (EMCAP) Study

RATIONALE

Basic science research suggests a causal role for endothelial dysfunction in chronic obstructive pulmonary disease (COPD). Clinical studies examining endothelial function are lacking, particularly early in the disease. Flow-mediated dilation (FMD) is a physiologic measure of endothelial reactivity to endogenous nitric oxide.

OBJECTIVES

We hypothesized that lower FMD among former smokers would be associated with lower post-bronchodilator FEV(1), higher percentage of emphysema using computed tomography (CT) and lower diffusing capacity.

METHODS

We measured FMD, pulmonary function, and CT percentage of emphysema in a random sample of 107 cotinine-confirmed former smokers in the ongoing EMCAP study. FMD was defined as percentage change in the brachial artery diameter with reactive hyperemia. Generalized additive models were used to adjust for potential confounders and assess linearity.

MEASUREMENTS AND MAIN RESULTS

Mean age of participants was 71 +/- 5 years, 46% were female, and pack-years averaged 48 +/- 26. Mean FMD was 3.8 +/- 3.1%; mean post-bronchodilator FEV(1), 2.3 +/- 0.8 L; and mean CT percentage of emphysema, 26 +/- 10%. A 1 SD decrease in FMD was associated with a 132-ml (95% confidence interval, 16-248 ml; P = 0.03) decrement in post-bronchodilator FEV(1) and a 2.6% (95% confidence interval, 0.5-4.7%; P = 0.02) increase in CT percentage of emphysema in fully adjusted models. These associations were linear across the spectrum from normality to disease, independent of smoking history, and also significant among participants without COPD. Associations with diffusing capacity were consistent but nonsignificant (P = 0.09). The FMD-FEV(1) association was entirely attributable to percentage of emphysema.

CONCLUSIONS

Impaired endothelial function, as measured by FMD, was associated with lower FEV(1) and higher CT percentage of emphysema in former smokers early in COPD.

Lung-volume reduction surgery for pulmonary emphysema: Improvement in body mass index, airflow obstruction, dyspnea, and exercise capacity index after 1 year

OBJECTIVES

We hypothesized that lung-volume reduction surgery for pulmonary emphysema would improve body mass index, airflow obstruction, dyspnea, and exercise capacity (BODE) index, a multidimensional predictor of survival in chronic obstructive pulmonary disease. We also aimed to identify preoperative predictors of improvement in the BODE index.

METHODS

In a prospective cohort study of patients undergoing lung-volume reduction surgery at our center, with the methodology of the National Emphysema Treatment Trial, we compared clinical characteristics before and 1 year after surgery with the Wilcoxon signed rank test. Changes in the BODE index were correlated with preoperative variables with the Spearman correlation coefficient.

RESULTS

Twenty-three patients with predominantly upper-lobe pulmonary emphysema underwent lung-volume reduction surgery (14 by video-assisted thoracoscopic surgery, 9 by median sternotomy). There were no postoperative or follow-up deaths. The BODE index improved from a median of 5 (interquartile range 4-5) before surgery to 3 (interquartile range 2-4) 1 year after surgery (P < .0001). Improvements were seen in the lung function and dyspnea components of the BODE index. Lower preoperative 6-minute walk distance and lower postwalk Borg fatigue scores were each associated with greater improvement in the BODE index after 1 year.

CONCLUSION

Lung-volume reduction surgery for pulmonary emphysema improved the BODE index in patients with predominantly upper-lobe disease. Lower preoperative 6-minute walk distance correlated with greater improvement in the BODE index.

Prediction of lung cancer using volatile biomarkers in breath1

BACKGROUND

Normal metabolism generates several volatile organic compounds (VOCs) that are excreted in the breath (e.g. alkanes). In patients with lung cancer, induction of high-risk cytochrome p450 genotypes may accelerate catabolism of these VOCs, so that their altered abundance in breath may provide biomarkers of lung cancer.

METHODS

VOCs in 1.0 L alveolar breath were analyzed in 193 subjects with primary lung cancer and 211 controls with a negative chest CT. Subjects were randomly assigned to a training set or to a prediction set in a 2:1 split. A fuzzy logic model of breath biomarkers of lung cancer was constructed in the training set and then tested in subjects in the prediction set by generating their typicality scores for lung cancer.

RESULTS

Mean typicality scores employing a 16 VOC model were significantly higher in lung cancer patients than in the control group (p<0.0001 in all TNM stages). The model predicted primary lung cancer with 84.6% sensitivity, 80.0% specificity, and 0.88 area under curve (AUC) of the receiver operating characteristic (ROC) curve. Predictive accuracy was similar in TNM stages 1 through 4, and was not affected by current or former tobacco smoking. The predictive model achieved near-maximal performance with six breath VOCs, and was progressively degraded by random classifiers. Predictions with fuzzy logic were consistently superior to multilinear analysis. If applied to a population with 2% prevalence of lung cancer, a screening breath test would have a negative predictive value of 0.985 and a positive predictive value of 0.163 (true positive rate =0.277, false positive rate =0.029).

CONCLUSIONS

A two-minute breath test predicted lung cancer with accuracy comparable to screening CT of chest. The accuracy of the test was not affected by TNM stage of disease or tobacco smoking. Alterations in breath VOCs in lung cancer were consistent with a non-linear pathophysiologic process, such as an off-on switch controlling high-risk cytochrome p450 activity. Further research is needed to determine if detection of lung cancer with this test will reduce mortality.

Clinical predictors of metastatic disease to the brain from non-small cell lung carcinoma: primary tumor size, cell type, and lymph node metastases

PURPOSE

To retrospectively assess possible clinical predictors of metastatic disease to the brain in patients with non-small cell lung carcinoma (NSCLC).

MATERIALS AND METHODS

Institutional review board approval was obtained, informed consent was waived, and data and other information were obtained prior to implementation of HIPAA. A review was performed of 264 patients (mean age, 65 years; 158 men and 106 women) with NSCLC who had undergone imaging studies of the chest and head. Hierarchical logistic regression was used to determine the predicted probability of metastatic disease to the brain as a function of patient age and sex and of size, cell type, peripheral versus central location, and lymph node stage of the primary NSCLC.

RESULTS

Ninety-five (36%) patients had evidence of metastatic disease to the brain. Mean diameter of the primary tumors was 4.0 cm +/- 2.2 (standard deviation). Cell types included adenocarcinoma (136 [52%] patients), undifferentiated (68 [26%] patients), and squamous (47 [18%] patients), for which metastatic disease to the brain occurred in 43%, 41%, and 13% (P = .003) of patients, respectively. The predicted probability of metastatic disease to the brain correlated positively with size of the primary tumor (P < .001), cell type (adenocarcinoma and undifferentiated vs squamous, P = .001), and lymph node stage (P < .017) but did not correlate with age, sex, or primary tumor location. For primary adenocarcinoma without lymph node spread, the predicted probabilities of metastatic disease to the brain from 2- and 6-cm primary tumors were .14 (95% confidence interval: .06, .27) and .72 (95% confidence interval: .48, .88), respectively (P < .02).

CONCLUSION

The probability of metastatic disease to the brain from primary NSCLC is correlated with size of the primary tumor, cell type, and intrathoracic lymph node stage.

Aortic Valve Calcification as an Incidental Finding at CT of the Elderly: Severity and Location as Predictors of Aortic Stenosis

OBJECTIVE

The purpose of this study was to correlate the severity and location of aortic valve calcifications, as an incidental finding at chest CT of elderly persons, with pressure gradients across the valve.

MATERIALS AND METHODS

One hundred fifteen subjects who were 60 years old or older and who showed aortic valve calcification on chest CT (5-mm reconstructed section width, no IV contrast material) and who had also undergone transthoracic echocardiography within 3 months of the CT examination were identified retrospectively. Aortic valve calcification scores (Agatston and volumetric) and subjective calcification pattern scores (based on a 9-point scale) were calculated and correlated with echocardiographic gradients.

RESULTS

Thirty patients (26%) (median age, 81 years) were identified who showed an increased pressure gradient across the aortic valve at echocardiography. Eighty-five subjects (74%), including 30 age-matched but otherwise randomly selected control subjects, showed no increase in pressure gradient. The severity of aortic valve calcification was greater for the 30 subjects with an increased gradient than for the control subjects (p < 0.0001). Increased mean and peak gradients across the aortic valve correlated with the subjective scores for aortic valve calcification (r = 0.69 and 0.65, respectively; p < 0.0001), with Agatston scores (r = 0.76 and 0.70, respectively; p < 0.0001), and with volumetric scores (r = 0.78 and 0.73, respectively; p < 0.0001). In terms of specific commissures, the greatest correlation with mean and peak gradients was for peripheral left-posterior commissural calcification (r = 0.71 and 0.65, respectively; p < 0.0001) and central right-left commissural calcification (r = 0.69 and 0.66, respectively; p < 0.0001).

CONCLUSION

The severity of aortic valve calcifications on chest CT, as assessed either subjectively or objectively, correlated with increased pressure gradients across the aortic valve, particularly for calcification of the peripheral left-posterior commissure and the central right-left commissure. These results indicate that the severity and location of aortic valve calcifications on chest CT are associated with an increased pressure gradient across the aortic valve.

Guidelines for Management of Small Pulmonary Nodules Detected on CT Scans: A Statement from the Fleischner Society

Lung nodules are detected very commonly on computed tomographic (CT) scans of the chest, and the ability to detect very small nodules improves with each new generation of CT scanner. In reported studies, up to 51% of smokers aged 50 years or older have pulmonary nodules on CT scans. However, the existing guidelines for follow-up and management of noncalcified nodules detected on nonscreening CT scans were developed before widespread use of multi-detector row CT and still indicate that every indeterminate nodule should be followed with serial CT for a minimum of 2 years. This policy, which requires large numbers of studies to be performed at considerable expense and with substantial radiation exposure for the affected population, has not proved to be beneficial or cost-effective. During the past 5 years, new information regarding prevalence, biologic characteristics, and growth rates of small lung cancers has become available; thus, the authors believe that the time-honored requirement to follow every small indeterminate nodule with serial CT should be revised. In this statement, which has been approved by the Fleischner Society, the pertinent data are reviewed, the authors' conclusions are summarized, and new guidelines are proposed for follow-up and management of small pulmonary nodules detected on CT scans.

Influence of Type of Cigarette on Peripheral versus Central Lung Cancer

OBJECTIVES

Adenocarcinoma has replaced squamous cell carcinoma as the most common cell type of lung cancer in the United States. It has been proposed that this shift is due to the increased use of filter and lower-tar cigarettes, resulting in increased delivery of smoke to peripheral regions of the lungs, where adenocarcinoma usually occurs. We reviewed radiologic data to evaluate the hypothesis that tumors in smokers of cigarettes with lower-tar yield are more likely to occur peripherally than tumors in smokers of higher-yield cigarettes.

METHODS

At two urban academic medical centers, we reviewed computed tomographic scans, chest radiographs, and medical records to assign tumor location (peripheral or central) for 330 smokers diagnosed with carcinoma of the lung between 1993 and 1999. We compared the proportion of tumors in a peripheral versus central location by lifetime filter use and average lifetime tar rating (< 21 and > or = 21 mg).

RESULTS

Tumor location (69% peripheral and 31% central) was unrelated to cigarette filter use. Smokers of cigarettes with lower-tar ratings were more likely than those with higher ratings to have peripheral rather than central tumors (odds ratio, 1.76; 95% confidence interval, 0.89-3.47). When restricted to subjects with adenocarcinoma or squamous cell carcinoma, the odds ratio (95% confidence interval) was 2.31 (1.05-5.08).

CONCLUSIONS

Among cigarette smokers with lung cancer, use of cigarettes with lower-tar yield was associated with preferential occurrence of tumors in peripheral sites. Our findings support the hypothesis that changes in smoking associated with lower-tar cigarettes have led to a shift in the location of smoking-related lung cancer.

Adenosquamous carcinoma of the lung: CT—pathological correlation

AIM

To correlate CT morphological features and histopathological findings of adenosquamous carcinoma of the lung.

MATERIALS AND METHODS

In all, 29 patients underwent contrast-enhanced CT of an adenosquamous carcinoma of the lung, followed by resection of the cancer. Correlations between CT morphological and histopathological features were evaluated, including location, characteristics of margins, attenuation and the presence of necrosis.

RESULTS

The tumour was peripheral in 21 (72%) and central in 8 (28%) cases. The tumours varied in size from 1.1cm to 11.0cm (mean 3.8cm); 20 (69%) appeared as heterogeneous masses and 9 (31%) as homogeneous masses. The most common CT features were lobulation in 27 (93%), pleural tail in 22 (76%), spiculation in 17 (59%), necrosis in 15 (52%) and vessel convergence in 13 (45%). Among the 21 peripheral tumours, 14 (67%) showed intratumoural necrosis and 17 (81%) were heterogeneous. Among the 8 central tumours, only 1 (12.5%) showed intratumoural necrosis and 5 (62.5%) were homogeneous. These CT features corresponded mainly to solid tumour growth, which was composed of both squamous cell carcinomatous and adenocarcinomatous tissue.

CONCLUSION

Adenosquamous carcinoma of the lung is shown to be characteristically a solid, lobulated nodule or mass, more commonly peripheral than central. After intravenous injection of positive contrast medium, CT shows that the peripheral lesions are usually of heterogeneous soft-tissue attenuation.

Molecular Signatures in Biopsy Specimens of Lung Cancer

Gene expression profiles of resected tumors may predict treatment response and outcome. We hypothesized that profiles derived from lung tumor biopsies would discriminate tumor-specific gene signatures and provide predictive information about outcome. Lung carcinoma specimens were obtained from 23 patients undergoing computed tomography-guided transthoracic biopsy or endobronchial brushing for undiagnosed nodules. Excess tissue was processed for gene profiling. We built class prediction models for lung cancer histology and for cancer outcome. The histology model used an F test to identify 99 genes that were differentially expressed among lung cancer subtypes. The histology validation set class prediction accuracy rate was 86%. The outcome model used the maximum difference subset algorithm to identify 42 genes associated with high risk for cancer death. The outcome training set class prediction accuracy rate was 87%. In conclusion, gene expression profiles of biopsy specimens of lung cancers identify unique tumoral signatures that provide information about tissue morphology and prognosis. The use of specimens acquired from lung biopsy procedures to identify biomarkers of clinical outcome may have application in the management of patients with lung cancer. The procedures are safe and feasible; the efficacy and utility of this strategy will ultimately be determined by prospective clinical trials.