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Li TZ, Hin Lee H, Xu K, Gao R, Dawant BM, Maldonado F, Sandler KL, Landman BA. Quantifying emphysema in lung screening computed tomography with robust automated lobe segmentation. J Med Imaging (Bellingham) 2023; 10:044002. [PMID: 37469854 PMCID: PMC10353481 DOI: 10.1117/1.jmi.10.4.044002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 06/14/2023] [Accepted: 06/21/2023] [Indexed: 07/21/2023] Open
Abstract
Purpose Anatomy-based quantification of emphysema in a lung screening cohort has the potential to improve lung cancer risk stratification and risk communication. Segmenting lung lobes is an essential step in this analysis, but leading lobe segmentation algorithms have not been validated for lung screening computed tomography (CT). Approach In this work, we develop an automated approach to lobar emphysema quantification and study its association with lung cancer incidence. We combine self-supervised training with level set regularization and finetuning with radiologist annotations on three datasets to develop a lobe segmentation algorithm that is robust for lung screening CT. Using this algorithm, we extract quantitative CT measures for a cohort (n = 1189 ) from the National Lung Screening Trial and analyze the multivariate association with lung cancer incidence. Results Our lobe segmentation approach achieved an external validation Dice of 0.93, significantly outperforming a leading algorithm at 0.90 (p < 0.01 ). The percentage of low attenuation volume in the right upper lobe was associated with increased lung cancer incidence (odds ratio: 1.97; 95% CI: [1.06, 3.66]) independent of PLCO m 2012 risk factors and diagnosis of whole lung emphysema. Quantitative lobar emphysema improved the goodness-of-fit to lung cancer incidence (χ 2 = 7.48 , p = 0.02 ). Conclusions We are the first to develop and validate an automated lobe segmentation algorithm that is robust to smoking-related pathology. We discover a quantitative risk factor, lending further evidence that regional emphysema is independently associated with increased lung cancer incidence. The algorithm is provided at https://github.com/MASILab/EmphysemaSeg.
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Affiliation(s)
- Thomas Z. Li
- Vanderbilt University, Department of Biomedical Engineering, Nashville, Tennessee, United States
- Vanderbilt University, School of Medicine, Nashville, Tennessee, United States
| | - Ho Hin Lee
- Vanderbilt University, Department of Biomedical Engineering, Nashville, Tennessee, United States
| | - Kaiwen Xu
- Vanderbilt University, Department of Computer Science, Nashville, Tennessee, United States
| | - Riqiang Gao
- Vanderbilt University, Department of Computer Science, Nashville, Tennessee, United States
| | - Benoit M. Dawant
- Vanderbilt University, Department of Biomedical Engineering, Nashville, Tennessee, United States
- Vanderbilt University, Department of Computer Science, Nashville, Tennessee, United States
- Vanderbilt University, Department of Electrical and Computer Engineering, Nashville, Tennessee, United States
- Vanderbilt University Medical Center, Department of Radiology and Radiological Sciences, Nashville, Tennessee, United States
| | - Fabien Maldonado
- Vanderbilt University Medical Center, Department of Medicine, Nashville, Tennessee, United States
| | - Kim L. Sandler
- Vanderbilt University Medical Center, Department of Radiology and Radiological Sciences, Nashville, Tennessee, United States
| | - Bennett A. Landman
- Vanderbilt University, Department of Biomedical Engineering, Nashville, Tennessee, United States
- Vanderbilt University, Department of Computer Science, Nashville, Tennessee, United States
- Vanderbilt University, Department of Electrical and Computer Engineering, Nashville, Tennessee, United States
- Vanderbilt University Medical Center, Department of Radiology and Radiological Sciences, Nashville, Tennessee, United States
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Yang X, Wisselink HJ, Vliegenthart R, Heuvelmans MA, Groen HJM, Vonder M, Dorrius MD, de Bock GH. Association between Chest CT-defined Emphysema and Lung Cancer: A Systematic Review and Meta-Analysis. Radiology 2022; 304:322-330. [PMID: 35503012 DOI: 10.1148/radiol.212904] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Background Given the different methods of assessing emphysema, controversy exists as to whether it is associated with lung cancer. Purpose To perform a systematic review and meta-analysis of the association between chest CT-defined emphysema and the presence of lung cancer. Materials and Methods The PubMed, Embase, and Cochrane databases were searched up to July 15, 2021, to identify studies on the association between emphysema assessed visually or quantitatively with CT and lung cancer. Associations were determined by emphysema severity (trace, mild, or moderate to severe, assessed visually and quantitatively) and subtype (centrilobular and paraseptal, assessed visually). Overall and stratified pooled odds ratios (ORs) with their 95% CIs were obtained. Results Of the 3343 screened studies, 21 studies (107 082 patients) with 26 subsets were included. The overall pooled ORs for lung cancer given the presence of emphysema were 2.3 (95% CI: 2.0, 2.6; I2 = 35%; 19 subsets) and 1.02 (95% CI: 1.01, 1.02; six subsets) per 1% increase in low attenuation area. Studies with visual (pooled OR, 2.3; 95% CI: 1.9, 2.6; I2 = 48%; 12 subsets) and quantitative (pooled OR, 2.2; 95% CI: 1.8, 2.8; I2 = 3.7%; eight subsets) assessments yielded comparable results for the dichotomous assessment. Based on six studies (1716 patients), the pooled ORs for lung cancer increased with emphysema severity and were higher for visual assessment (2.5, 3.7, and 4.5 for trace, mild, and moderate to severe, respectively) than for quantitative assessment (1.9, 2.2, and 2.5) based on point estimates. Compared with no emphysema, only centrilobular emphysema (three studies) was associated with lung cancer (pooled OR, 2.2; 95% CI: 1.5, 3.2; P < .001). Conclusion Both visual and quantitative CT assessments of emphysema were associated with a higher odds of lung cancer, which also increased with emphysema severity. Regarding subtype, only centrilobular emphysema was significantly associated with lung cancer. Clinical trial registration no. CRD42021262163 © RSNA, 2022 See also the editorial by Hunsaker in this issue. Online supplemental material is available for this article.
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Affiliation(s)
- Xiaofei Yang
- From the Departments of Epidemiology (X.Y., M.A.H., M.V., M.D.D., G.H.d.B.), Radiology (H.J.W., R.V., M.D.D.), and Pulmonary Diseases (H.J.M.G.), University Medical Center Groningen, University of Groningen, 9700 RB Groningen, the Netherlands
| | - Hendrik Joost Wisselink
- From the Departments of Epidemiology (X.Y., M.A.H., M.V., M.D.D., G.H.d.B.), Radiology (H.J.W., R.V., M.D.D.), and Pulmonary Diseases (H.J.M.G.), University Medical Center Groningen, University of Groningen, 9700 RB Groningen, the Netherlands
| | - Rozemarijn Vliegenthart
- From the Departments of Epidemiology (X.Y., M.A.H., M.V., M.D.D., G.H.d.B.), Radiology (H.J.W., R.V., M.D.D.), and Pulmonary Diseases (H.J.M.G.), University Medical Center Groningen, University of Groningen, 9700 RB Groningen, the Netherlands
| | - Marjolein A Heuvelmans
- From the Departments of Epidemiology (X.Y., M.A.H., M.V., M.D.D., G.H.d.B.), Radiology (H.J.W., R.V., M.D.D.), and Pulmonary Diseases (H.J.M.G.), University Medical Center Groningen, University of Groningen, 9700 RB Groningen, the Netherlands
| | - Harry J M Groen
- From the Departments of Epidemiology (X.Y., M.A.H., M.V., M.D.D., G.H.d.B.), Radiology (H.J.W., R.V., M.D.D.), and Pulmonary Diseases (H.J.M.G.), University Medical Center Groningen, University of Groningen, 9700 RB Groningen, the Netherlands
| | - Marleen Vonder
- From the Departments of Epidemiology (X.Y., M.A.H., M.V., M.D.D., G.H.d.B.), Radiology (H.J.W., R.V., M.D.D.), and Pulmonary Diseases (H.J.M.G.), University Medical Center Groningen, University of Groningen, 9700 RB Groningen, the Netherlands
| | - Monique D Dorrius
- From the Departments of Epidemiology (X.Y., M.A.H., M.V., M.D.D., G.H.d.B.), Radiology (H.J.W., R.V., M.D.D.), and Pulmonary Diseases (H.J.M.G.), University Medical Center Groningen, University of Groningen, 9700 RB Groningen, the Netherlands
| | - Geertruida H de Bock
- From the Departments of Epidemiology (X.Y., M.A.H., M.V., M.D.D., G.H.d.B.), Radiology (H.J.W., R.V., M.D.D.), and Pulmonary Diseases (H.J.M.G.), University Medical Center Groningen, University of Groningen, 9700 RB Groningen, the Netherlands
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3
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Uthoff JM, Mott SL, Larson J, Neslund-Dudas CM, Schwartz AG, Sieren JC. Computed Tomography Features of Lung Structure Have Utility for Differentiating Malignant and Benign Pulmonary Nodules. CHRONIC OBSTRUCTIVE PULMONARY DISEASES (MIAMI, FLA.) 2022; 9:154-164. [PMID: 35021316 PMCID: PMC9166332 DOI: 10.15326/jcopdf.2021.0271] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/12/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND Chronic obstructive pulmonary disease (COPD) is a known comorbidity for lung cancer independent of smoking history. Quantitative computed tomography (qCT) imaging features related to COPD have shown promise in the assessment of lung cancer risk. We hypothesize that qCT features from the lung, lobe, and airway tree related to the location of the pulmonary nodule can be used to provide informative malignancy risk assessment. METHODS A total of 183 qCT features were extracted from 278 individuals with a solitary pulmonary nodule of known diagnosis (71 malignant, 207 benign). These included histogram and airway characteristics of the lungs, lobe, and segmental paths. Performances of the least absolute shrinkage and selection operator (LASSO) regression analysis and an ensemble of neural networks (ENN) were compared for feature set selection and classification on a testing cohort of 49 additional individuals (15 malignant, 34 benign). RESULTS The LASSO and ENN methods produced different feature sets for classification with LASSO selecting fewer qCT features (7) than the ENN (17). The LASSO model with the highest performing training area under the curve (AUC) (0.80) incorporated automatically extracted features and reader-measured nodule diameter with a testing AUC of 0.62. The ENN model with the highest performing AUC (0.77) also incorporated qCT and reader diameter but maintained higher testing performance AUC (0.79). CONCLUSIONS Automatically extracted qCT imaging features of the lung can be informative of the differentiation between individuals with malignant pulmonary nodules and those with benign pulmonary nodules, without requiring nodule segmentation and analysis.
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Affiliation(s)
- Johanna M. Uthoff
- Department of Radiology, University of Iowa, Iowa City, Iowa, United States
- Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa, United States
- Holden Comprehensive Cancer Center, University of Iowa, Iowa City, Iowa, United States
| | - Sarah L. Mott
- Holden Comprehensive Cancer Center, University of Iowa, Iowa City, Iowa, United States
| | - Jared Larson
- Department of Radiology, University of Iowa, Iowa City, Iowa, United States
| | - Christine M. Neslund-Dudas
- Department of Public Health Sciences, Henry Ford Health System, Detroit, Michigan, United States
- Henry Ford Cancer Institute, Henry Ford Health System, Detroit, Michigan, United States
| | - Ann G. Schwartz
- Karmanos Cancer Institute, Wayne State University, Detroit, Michigan, United States
| | - Jessica C. Sieren
- Department of Radiology, University of Iowa, Iowa City, Iowa, United States
- Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa, United States
- Holden Comprehensive Cancer Center, University of Iowa, Iowa City, Iowa, United States
| | - the COPDGene® Investigators
- Department of Radiology, University of Iowa, Iowa City, Iowa, United States
- Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa, United States
- Holden Comprehensive Cancer Center, University of Iowa, Iowa City, Iowa, United States
- Department of Public Health Sciences, Henry Ford Health System, Detroit, Michigan, United States
- Henry Ford Cancer Institute, Henry Ford Health System, Detroit, Michigan, United States
- Karmanos Cancer Institute, Wayne State University, Detroit, Michigan, United States
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Irie H, Ozaki M, Chubachi S, Hegab AE, Tsutsumi A, Kameyama N, Sakurai K, Nakayama S, Kagawa S, Wada S, Ishii M, Betsuyaku T, Fukunaga K. Short-term intermittent cigarette smoke exposure enhances alveolar type 2 cell stemness via fatty acid oxidation. Respir Res 2022; 23:41. [PMID: 35236337 PMCID: PMC8889685 DOI: 10.1186/s12931-022-01948-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 02/07/2022] [Indexed: 11/24/2022] Open
Abstract
Background Cigarette smoke (CS) is associated with chronic obstructive pulmonary disease (COPD) and cancer. However, the underlying pathological mechanisms are not well understood. We recently reported that mice exposed to long-term intermittent CS for 3 months developed more severe emphysema and higher incidence of adenocarcinoma than mice exposed to long-term continuous CS for 3 months and long-term continuous CS exposure activated alveolar stem cell proliferation. However, the influence of variations in the CS exposure pattern in alveolar stem cell in unknown. Here, we exposed mice to 3 weeks of continuous or intermittent CS to identify whether different CS exposure patterns would result in differential effects on stem cells and the mechanisms underlying these potential differences. Methods Female mice expressing GFP in alveolar type 2 (AT2) cells, which are stem cells of the alveolar compartment, were exposed to mainstream CS via nasal inhalation. AT2 cells were collected based on their GFP expression by flow cytometry and co-cultured with fibroblasts in stem cell 3D organoid/colony-forming assays. We compared gene expression profiles of continuous and intermittent CS-exposed AT2 cells using microarray analysis and performed a functional assessment of a differentially expressed gene to confirm its involvement in the process using activator and inhibitor studies. Results AT2 cells sorted from intermittent CS-exposed mice formed significantly more colonies compared to those from continuous CS-exposed mice, and both CS-exposed groups formed significantly more colonies when compared to air-exposed cells. Comparative microarray analysis revealed the upregulation of genes related to fatty acid oxidation (FAO) pathways in AT2 cells from intermittent CS-exposed mice. Treatment of intermittent CS-exposed mice with etomoxir, an inhibitor of the FAO regulator Cpt1a, for 5 weeks resulted in a significant suppression of the efficiency of AT2 cell colony formation. In vitro treatment of naïve AT2 cells with a FAO activator and inhibitor further confirmed the relationship between FAO and AT2 stem cell function. Conclusions Alveolar stem cell function was more strongly activated by intermittent CS exposure than by continuous CS exposure. We provide evidence that AT2 stem cells respond to intermittent CS exposure by activating stem cell proliferation via the activation of FAO. Supplementary Information The online version contains supplementary material available at 10.1186/s12931-022-01948-4.
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Affiliation(s)
- Hidehiro Irie
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Mari Ozaki
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Shotaro Chubachi
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan.
| | - Ahmed E Hegab
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan.
| | - Akihiro Tsutsumi
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Naofumi Kameyama
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Kaori Sakurai
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Shingo Nakayama
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Shizuko Kagawa
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Sachika Wada
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Makoto Ishii
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Tomoko Betsuyaku
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Koichi Fukunaga
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
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5
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Carr LL, Dyer DS, Zelarney PT, Kern EO. Improvement in Stage of Lung Cancer Diagnosis with Incident Pulmonary Nodules followed with a Patient Tracking System and Computerized Registry. JTO Clin Res Rep 2022; 3:100297. [PMID: 35310139 PMCID: PMC8924678 DOI: 10.1016/j.jtocrr.2022.100297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 02/09/2022] [Accepted: 02/13/2022] [Indexed: 11/30/2022] Open
Abstract
Introduction Given that an incidental pulmonary nodule (IPN) on chest computed tomography (CT) may represent nascent lung cancer, timely follow-up imaging is critical to assess nodule growth and the need for tissue sampling. We previously reported our institution’s systematic process to identify and track patients with an IPN associated with improved CT on follow-up. We hypothesized that this improvement may have led to a higher frequency of early-stage lung cancer. To evaluate this, we performed a study to determine whether cases of early-stage lung cancer were more likely to have had our tracking system applied to suspicious findings. Methods An observational study was performed by identifying cases of lung cancer that were detected as IPNs on chest CT scans performed at our institution, from 2006 to 2016. A total of 314 cases were dichotomized into early-stage (stage 1) or late-stage (stages II to IV) disease. A multivariant regression analysis with modeling was used to determine factors associated with a diagnosis of early-stage disease. Factors included the use of the tracking system and nodule registry. Results The following factors were independently associated with early-stage lung cancer: index nodule diameter, (OR = 0.971, confidence interval [CI]: 0.948–0.995], p = 0.016), adenocarcinoma histology (OR = 2.930 [CI: 1.695–5.064], p = 0.0001) and use of tracker phrases on CT reports (OR = 1.939 [CI: 1.126–3.339], p = 0.016). Conclusions The application of a patient tracking system and computerized lung nodule registry lead to an increased frequency in the diagnosis of stage 1 NSCLC from IPNs. This is a meaningful outcome for patients and should be adapted for IPN management.
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Affiliation(s)
- Laurie L. Carr
- Division of Oncology, Department of Medicine, National Jewish Health, Denver, Colorado
- Corresponding author. Address for correspondence: Laurie L. Carr, MD, Division of Oncology, Department of Medicine, National Jewish Health, 1400 Jackson Street, J328, Denver, CO 80207.
| | - Debra S. Dyer
- Department of Radiology, National Jewish Health, Denver, Colorado
| | | | - Elizabeth O. Kern
- Division of Medical, Behavioral, and Community Health, Department of Medicine, National Jewish Health, Denver, Colorado
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6
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Axelsson GT, Gudmundsson G. Interstitial lung abnormalities - current knowledge and future directions. Eur Clin Respir J 2021; 8:1994178. [PMID: 34745461 PMCID: PMC8567914 DOI: 10.1080/20018525.2021.1994178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Efforts to grasp the significance of radiologic changes similar to interstitial lung disease (ILD) in undiagnosed individuals have intensified in the recent decade. The term interstitial lung abnormalities (ILA) is an emerging definition of such changes, defined by visual examination of computed tomography scans. Substantial insights have been made in the origins and clinical consequences of these changes, as well as automated measures of early lung fibrosis, which will likely lead to increased recognition of early fibrotic lung changes among clinicians and researchers alike. Interstitial lung abnormalities have an estimated prevalence of 7–10% in elderly populations. They correlate with many ILD risk factors, both epidemiologic and genetic. Additionally, histopathological similarities with IPF exist in those with ILA. While no established blood biomarker of ILA exists, several have been suggested. Distinct imaging patterns indicating advanced fibrosis correlate with worse clinical outcomes. ILA are also linked with adverse clinical outcomes such as increased mortality and risk of lung cancer. Progression of ILA has been noted in a significant portion of those with ILA and is associated with many of the same features as ILD, including advanced fibrosis. Those with ILA progression are at risk of accelerated FVC decline and increased mortality. Radiologic changes resembling ILD have also been attained by automated measures. Such measures associate with some, but not all the same factors as ILA. ILA and similar radiologic changes are in many ways analogous to ILD and likely represent a precursor of ILD in some cases. While warranting an evaluation for ILD, they are associated with poor clinical outcomes beyond possible ILD development and thus are by themselves a significant finding. Among the present objectives of this field are the stratification of patients with regards to progression and the discovery of biomarkers with predictive value for clinical outcomes.
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Affiliation(s)
- Gisli Thor Axelsson
- Faculty of Medicine, University of Iceland, Reykjavik, Iceland.,Icelandic Heart Association, Kopavogur, Iceland
| | - Gunnar Gudmundsson
- Faculty of Medicine, University of Iceland, Reykjavik, Iceland.,Department of Respiratory Medicine and Sleep, Landspitali University Hospital, Reykjavik, Iceland
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7
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Meteran H, Thomsen SF, Miller MR, Hjelmborg J, Sigsgaard T, Backer V. Impact of the spirometric definition on comorbidities in chronic obstructive pulmonary disease. Respir Med 2021; 184:106399. [PMID: 34000574 DOI: 10.1016/j.rmed.2021.106399] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 03/30/2021] [Accepted: 04/09/2021] [Indexed: 12/15/2022]
Abstract
BACKGROUND Little is known about how the spirometric definition of airway obstruction affects the association between COPD and comorbidities and whether these associations might be due to genetic predisposition. AIM 1) To examine the impact of the spirometric definition on the associations between COPD and its comorbidities and 2) To examine whether these associations can be explained by shared genetic or environmental factors. METHODS 11,458 twins, aged 40-80 years, from the Danish Twin Registry were recruited who completed a questionnaire on medical history, life style factors and had a clinical examination. COPD was defined by respiratory symptoms (RS) plus airway obstruction according to either GOLD (FR-COPD) or ERS/ATS guidelines (LLN-COPD). Self-reported physician diagnoses were used to identify comorbidities. RESULTS The mean age of participants was 58.4 years ±SD 9.7, mean BMI was 26.6 kg/m2 ± SD 4.4, 52% were female and the prevalence of LLN2.5-COPD and FR-COPD was 2.5% and 6.3%, respectively. Among eight major comorbidities, multivariate logistic regression showed COPD was only associated with heart failure, whereas RS alone were associated with 6 out of 8 comorbidities after Bonferroni-correction. There was an increased risk of heart failure, ischemic heart disease, depression and pulmonary embolism in twin individuals with RS compared with the co-twin without RS. CONCLUSIONS COPD was only associated with an increased risk of heart failure. Discordant COPD-individuals (FR-COPD+/LLN5-COPD-) were at increased risk of heart failure. Sub-analyses showed that RS, but not airway obstruction were associated with an increased risk of comorbidities.
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Affiliation(s)
- Howraman Meteran
- Department of Internal Medicine, Respiratory Medicine Section, Copenhagen University Hospital-Herlev-Gentofte, Hellerup, Denmark; Department of Public Health, Section of Environment Occupation and Health, Danish Ramazzini Centre, University of Aarhus, Aarhus C, Denmark; Department of Microbiology and Immunology, University of Copenhagen, Denmark.
| | - Simon Francis Thomsen
- Department of Dermatology, Copenhagen University Hospital-Bispebjerg-Frederiksberg, Copenhagen, Denmark; Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Martin R Miller
- Institute of Applied Health Sciences, University of Birmingham, Birmingham, UK
| | - Jacob Hjelmborg
- The Danish Twin Registry, Epidemiology and Biostatistics, Institute of Public Health, University of Southern Denmark, Odense, Denmark
| | - Torben Sigsgaard
- Department of Public Health, Section of Environment Occupation and Health, Danish Ramazzini Centre, University of Aarhus, Aarhus C, Denmark
| | - Vibeke Backer
- Centre of Inflammation and Metabolism, Centre for Physical Activity Research, Copenhagen University Hospital-Rigshospitalet, Copenhagen, Denmark; Department of Otorhinolaryngology, Head and Neck Surgery and Audiology, Copenhagen University Hospital-Rigshospitalet, Copenhagen, Denmark
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8
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Machida H, Inoue S, Shibata Y, Kimura T, Ota T, Ishibashi Y, Murano H, Furuyama K, Yang S, Nakano H, Sato K, Sato M, Nemoto T, Nishiwaki M, Yamauchi K, Igarashi A, Watanabe M. The Incidence and Risk Analysis of Lung Cancer Development in Patients with Chronic Obstructive Pulmonary Disease: Possible Effectiveness of Annual CT-Screening. Int J Chron Obstruct Pulmon Dis 2021; 16:739-749. [PMID: 33790550 PMCID: PMC8006963 DOI: 10.2147/copd.s287492] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 02/25/2021] [Indexed: 01/18/2023] Open
Abstract
Purpose Lung cancer is a serious complication in patients with chronic obstructive pulmonary disease (COPD) and accounts for approximately 15% of deaths in patients with COPD. However, with the exception of emphysema, few reports to date have been published on the factors that predict lung cancer development in COPD patients. It has been reported that patients with COPD develop lung cancer at a rate of 0.8% - 1.7%/year, but the incidence may be higher in the Japanese population. Therefore, we investigated the incidence of lung cancer and the lung cancer mortality rate in Japanese COPD patients, as well as factors that are associated with the development of lung cancer in COPD patients. Patients and Methods We followed up 224 patients with stable COPD and performed CT examinations at least once per year. The incidence of lung cancer was recorded and data at enrollment were compared with data of the group that did not develop lung cancer. Results Over a median follow-up period of 4.58 years, lung cancer was newly diagnosed in 19 patients; the incidence of lung cancer in this population was 1.85%/year. Patients who developed lung cancer had more severe emphysema assessed by CT and GOLD classification and were more likely to be current smokers than those who did not develop lung cancer. No other significant differences were observed between these two groups. Mortality was significantly increased in patients who developed lung cancer compared with those who did not. Conclusion In COPD patients, the incidence of lung cancer is higher and the development of lung cancer worsens the prognosis; however, lung cancer development is unpredictable and attention should be paid to all patients. Annual CT screening is important for early detection of lung cancer.
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Affiliation(s)
- Hiroyoshi Machida
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, Yamagata, Japan
| | - Sumito Inoue
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, Yamagata, Japan
| | - Yoko Shibata
- Department of Pulmonary Medicine, Fukushima Medical University, Fukushima, Japan
| | - Tomomi Kimura
- Respiratory Medicine, Yamagata Saisei Hospital, Yamagata, Japan
| | - Takahito Ota
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, Yamagata, Japan
| | - Yu Ishibashi
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, Yamagata, Japan
| | - Hiroaki Murano
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, Yamagata, Japan
| | - Kodai Furuyama
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, Yamagata, Japan
| | - Sujeong Yang
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, Yamagata, Japan
| | - Hiroshi Nakano
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, Yamagata, Japan
| | - Kento Sato
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, Yamagata, Japan
| | - Masamichi Sato
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, Yamagata, Japan
| | - Takako Nemoto
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, Yamagata, Japan
| | - Michiko Nishiwaki
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, Yamagata, Japan
| | - Keiko Yamauchi
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, Yamagata, Japan
| | - Akira Igarashi
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, Yamagata, Japan
| | - Masafumi Watanabe
- Department of Cardiology, Pulmonology, and Nephrology, Yamagata University Faculty of Medicine, Yamagata, Japan
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9
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Makino A, Tsuruta M, Okabayashi K, Ishida T, Shigeta K, Seishima R, Ikebata A, Koishikawa K, Hasegawa H, Shimoda M, Fukunaga K, Betsuyaku T, Kitagawa Y. The Impact of Smoking on Pulmonary Metastasis in Colorectal Cancer. Onco Targets Ther 2020; 13:9623-9629. [PMID: 33061444 PMCID: PMC7533240 DOI: 10.2147/ott.s263250] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 09/01/2020] [Indexed: 12/12/2022] Open
Abstract
Introduction Recently, clinical studies have revealed that smoking can contribute to the poor prognosis of colorectal cancer (CRC) and, additionally, can be a risk factor for pulmonary metastasis of CRC. However, there has been no basic research regarding the underlying molecular mechanism. The purpose of this study was to clarify the mechanism by which smoking causes pulmonary metastasis of CRC. Methods First, pulmonary metastasis model mice inhaled cigarette smoke or air (control) for 1 h once a day for 3 weeks. We attempted to clarify the effect of smoking on the incidence of pulmonary metastasis. On the 15th day, CMT-93 cells were injected into the tail vein. At 6 and 8 weeks following injection, the extent of pulmonary metastasis was evaluated using in vivo micro CT. After the last CT examination, the mice were sacrificed, and the lungs were extracted for pathological examination. Results The number of mice with pulmonary metastases in the smoking group was significantly higher than in the control group. Three weeks of smoking induced mild inflammation in the lungs, as evidenced by increases in the levels of IL-6 and TNF-α in bronchoalveolar lavage. Moreover, the adhesion-related molecule ICAM-1 was overexpressed in pulmonary tissue, which allowed drained cancer cells to remain in the lung and contribute to the formation of pulmonary metastasis. Conclusion Collectively, cigarette smoking may contribute to the pathogenesis and development of pulmonary metastasis in CRC through enhancement of adhesion and inflammation.
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Affiliation(s)
- Akitsugu Makino
- Department of Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Masashi Tsuruta
- Department of Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Koji Okabayashi
- Department of Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Takashi Ishida
- Department of Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Kohei Shigeta
- Department of Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Ryo Seishima
- Department of Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Akiyoshi Ikebata
- Department of Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Kaoru Koishikawa
- Department of Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Hirotoshi Hasegawa
- Department of Surgery, Tokyo Dental College Ichikawa General Hospital, Chiba, Japan
| | - Masayuki Shimoda
- Department of Pathology, Keio University School of Medicine, Tokyo, Japan
| | - Koichi Fukunaga
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan
| | - Tomoko Betsuyaku
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan
| | - Yuko Kitagawa
- Department of Surgery, Keio University School of Medicine, Tokyo, Japan
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10
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Tsutsumi A, Ozaki M, Chubachi S, Irie H, Sato M, Kameyama N, Sasaki M, Ishii M, Hegab AE, Betsuyaku T, Fukunaga K. Exposure to Cigarette Smoke Enhances the Stemness of Alveolar Type 2 Cells. Am J Respir Cell Mol Biol 2020; 63:293-305. [PMID: 32338993 DOI: 10.1165/rcmb.2019-0188oc] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 04/27/2020] [Indexed: 12/16/2022] Open
Abstract
Chronic exposure to cigarette smoke (CS) causes chronic inflammation, oxidative stress, and apoptosis of epithelial cells, which results in destruction of the lung matrix. However, the mechanism by which the lung fails to repair the CS-induced damage, thereby succumbing to emphysema, remains unclear. Alveolar type 2 (AT2) cells comprise the stem cells of the alveolar compartments and are responsible for repairing and maintaining lung tissues. In this study, we examined the effect of chronic CS on AT2 stem cells. Adult mice expressing GFP in their AT2 cells were exposed to CS for > 3 months. Histological assessment showed that CS not only induced emphysematous changes but also increased the number of AT2 cells compared with that of air-exposed lungs. Assessment of sorted GFP+/AT2 cells via the stem cell three-dimensional organoid/colony-forming assay revealed that the number and size of the colonies formed by the CS-exposed AT2 stem cells were significantly higher than those of air-exposed control AT2 cells. Although CS-exposed lungs had more apoptotic cells, examination of the surviving AT2 stem cells in two-dimensional in vitro culture revealed that they developed a higher ability to resist apoptosis. Microarray analysis of CS-exposed AT2 stem cells revealed the upregulation of genes related to circadian rhythm and inflammatory pathways. In conclusion, we provide evidence that AT2 stem cells respond to chronic CS exposure by activating their stem cell function, thereby proliferating and differentiating faster and becoming more resistant to apoptosis. Disturbances in expression levels of several circadian rhythm-related genes might be involved in these changes.
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Affiliation(s)
- Akihiro Tsutsumi
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan
| | - Mari Ozaki
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan
| | - Shotaro Chubachi
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan
| | - Hidehiro Irie
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan
| | - Minako Sato
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan
| | - Naofumi Kameyama
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan
| | - Mamoru Sasaki
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan
| | - Makoto Ishii
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan
| | - Ahmed E Hegab
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan
| | - Tomoko Betsuyaku
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan
| | - Koichi Fukunaga
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan
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11
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Nakayama S, Chubachi S, Sakurai K, Irie H, Tsutsumi A, Hashiguchi M, Itabashi Y, Murata M, Nakamura H, Asano K, Fukunaga K. Characteristics of Chronic Obstructive Pulmonary Disease Patients with Pulmonary Hypertension Assessed by Echocardiography in a Three-Year Observational Cohort Study. Int J Chron Obstruct Pulmon Dis 2020; 15:487-499. [PMID: 32184586 PMCID: PMC7060780 DOI: 10.2147/copd.s230952] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 02/14/2020] [Indexed: 01/25/2023] Open
Abstract
Background Pulmonary hypertension (PH) is a major comorbidity of chronic obstructive pulmonary disease (COPD). However, the association of PH detected by echocardiography and COPD-related outcome in longitudinal follow-up has not been elucidated. In this study, we aimed to investigate the relationship between clinical characteristics of COPD patients with PH detected by echocardiography and various outcome parameters such as COPD exacerbation and health status over a three-year observation period. Methods In this observational study, we analyzed patients with COPD who underwent chest computed tomography and echocardiography at baseline (n = 183). Results The prevalence of PH was 21.9% (40 patients). The median estimated systolic pulmonary artery pressure in patients with PH was 38.8 mmHg. COPD patients with PH were older, had a lower body mass index, scored worse in the COPD Assessment Test and St. George's Respiratory Questionnaire, and exhibited a lower diffusing capacity of the lung for carbon monoxide in comparison to patients without PH. In computed tomography images, the percentages of low-attenuation areas (LAA%) and interstitial abnormalities were higher in COPD patients with PH than in those without PH. Higher values for LAA% (LAA ≥ 30%) and interstitial abnormalities independently increased the risk of PH. The ratio of main pulmonary diameter to aortic artery diameter was significantly correlated with estimated systolic pulmonary artery pressure. In the follow-up analysis, the frequency of exacerbations in three years was significantly higher in patients with PH compared to patients without PH. Conclusion In this study, we identified the clinical characteristics of COPD patients with PH detected by echocardiography. The presence of PH assessed by echocardiography was related to future COPD exacerbations and closely related to radiographical emphysema.
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Affiliation(s)
- Shingo Nakayama
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Shotaro Chubachi
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Kaori Sakurai
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Hidehiro Irie
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Akihiro Tsutsumi
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Mizuha Hashiguchi
- Division of Pulmonary Medicine, Keiyu Hospital, Yokohama, Kanagawa 220-0012, Japan
| | - Yuji Itabashi
- Department of Laboratory Medicine, Keio University School of Medicine, Tokyo, Japan
| | - Mitsushige Murata
- Center for Preventive Medicine, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Hidetoshi Nakamura
- Division of Pulmonary Medicine, Saitama Medical University Hospital, Saitama 350-0495, Japan
| | - Koichiro Asano
- Division of Pulmonary Medicine, Department of Medicine, Tokai University School of Medicine, Isehara-Shi, Kanagawa 259-1193, Japan
| | - Koichi Fukunaga
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo 160-8582, Japan
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12
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Kameyama N, Chubachi S, Hegab AE, Yasuda H, Kagawa S, Tsutsumi A, Fukunaga K, Shimoda M, Kanai Y, Soejima K, Betsuyaku T. Intermittent Exposure to Cigarette Smoke Increases Lung Tumors and the Severity of Emphysema More than Continuous Exposure. Am J Respir Cell Mol Biol 2019; 59:179-188. [PMID: 29443539 DOI: 10.1165/rcmb.2017-0375oc] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Lung cancer and chronic obstructive pulmonary disease are leading causes of morbidity and mortality worldwide, and cigarette smoking is a main risk factor for both. The presence of emphysema, an irreversible lung disease, further raises the risk of lung cancer in patients with chronic obstructive pulmonary disease. The mechanisms involved in smoke-induced tumorigenesis and emphysema are not fully understood, attributable to a lack of appropriate animal models. Here, we optimized a model of cigarette smoke (CS)-induced lung cancer and emphysema in A/J mice treated with 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, a potent carcinogen. We investigated whether variations in CS exposure patterns with the same total amount and duration of exposure affect tumorigenesis and/or development of emphysema. Continuous CS exposure for 3 months significantly suppressed 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone-induced development of adenomas and adenocarcinomas; however, emphysema independently developed during this period. Surprisingly, intermittent CS exposure increased the severity of emphysema and resulted in a higher incidence of adenocarcinomas. Furthermore, intermittent CS exposure elicited a marked increase in M2-polarized macrophages within and near the developed tumors. By employing a CS exposure protocol with repeated cycles of cessation and relapse, we provide evidence that intermittent CS exposure enhances tumorigenesis and emphysema progression more than that of continuous CS exposure.
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Affiliation(s)
| | | | - Ahmed E Hegab
- 1 Division of Pulmonary Medicine, Department of Medicine, and
| | - Hiroyuki Yasuda
- 1 Division of Pulmonary Medicine, Department of Medicine, and
| | - Shizuko Kagawa
- 1 Division of Pulmonary Medicine, Department of Medicine, and
| | | | - Koichi Fukunaga
- 1 Division of Pulmonary Medicine, Department of Medicine, and
| | - Masayuki Shimoda
- 2 Department of Pathology, Keio University, School of Medicine, Tokyo, Japan
| | - Yae Kanai
- 2 Department of Pathology, Keio University, School of Medicine, Tokyo, Japan
| | - Kenzo Soejima
- 1 Division of Pulmonary Medicine, Department of Medicine, and
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13
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Kusumoto T, Asakura T, Suzuki S, Okamori S, Namkoong H, Fujiwara H, Yagi K, Kamata H, Ishii M, Betsuyaku T, Hasegawa N. Development of lung cancer in patients with nontuberculous mycobacterial lung disease. Respir Investig 2018; 57:157-164. [PMID: 30598398 DOI: 10.1016/j.resinv.2018.11.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 11/20/2018] [Accepted: 11/26/2018] [Indexed: 12/28/2022]
Abstract
BACKGROUND As lung cancer development in patients with nontuberculous mycobacterial lung disease (NTM-LD) has never been reported, we investigated its incidence and clinical characteristics. METHODS Prospective observational cohort registry (from June 2012 to June 2017), and retrospective identification by the International Classification of Diseases, tenth revision (between March 2010 and March 2018), were used to identify NTM-LD patients aged ≥20 years who developed lung cancer. RESULTS Eight patients (two men and six women, one with smoking history), having Mycobacterium avium complex lung disease (MAC-LD) were identified. Four were identified from retrospective chart reviews and four from the prospective observational cohort registry (n = 361, 289 women; 311 never-smokers). All patients underwent chest computed tomography (CT) at least once a year. The incidence rate of lung cancer developing in NTM-LD patients was 124.6 per 100,000 patient-years, which was higher than the lung cancer rate in Japan. The mean age at diagnosis of MAC-LD and lung cancer was 63.6 and 74.4 years, respectively. The most common lung cancer types were adenocarcinoma (six patients) followed by squamous cell carcinoma (two patients). Lung cancer was diagnosed at early and advanced clinical stages in seven and one patients, respectively. Outcomes were favorable, except in two patients: one with advanced stage disease, and another with poor performance status. CONCLUSIONS We identified the clinical characteristics of eight MAC-LD patients who developed lung cancer. NTM-LD may be a risk factor for lung cancer development. Periodic follow-up with chest CT might contribute to early diagnosis and curative therapy for lung cancer.
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Affiliation(s)
- Tatsuya Kusumoto
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Japan
| | - Takanori Asakura
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Japan
| | - Shoji Suzuki
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Japan
| | - Satoshi Okamori
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Japan
| | - Ho Namkoong
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Japan
| | - Hiroshi Fujiwara
- Center for Infectious Diseases and Infection Control, Keio University School of Medicine, Japan
| | - Kazuma Yagi
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Japan
| | - Hirofumi Kamata
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Japan
| | - Makoto Ishii
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Japan
| | - Tomoko Betsuyaku
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Japan
| | - Naoki Hasegawa
- Center for Infectious Diseases and Infection Control, Keio University School of Medicine, Japan.
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