Tatsuya Chonan

Publications (8)26.98 Total impact

• Article: A decrease in lung cancer mortality following the introduction of low-dose chest CT screening in Hitachi, Japan.

  Takeshi Nawa, Tohru Nakagawa, Tetsuya Mizoue, Suzushi Kusano, Tatsuya Chonan, Kenji Hayashihara, Tetsushi Suito, Katsuyuki Endo
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  ABSTRACT: Recent US clinical trial demonstrated that CT screening prevents lung cancer death among high risk individuals. However, it remains unclear whether wide implementation of low-dose CT screening for lung cancer can decrease mortality in the community. Among residents in Hitachi City (Japan), where nearly 40% of inhabitants aged 50-69 years were estimated to have participated in the screening at least once from 1998 through 2009, the trend of lung cancer mortality was described in relation to the timing of implementation of the CT screening. Cancer mortality data were obtained from regional cancer registry and standardized mortality ratio (SMR) of lung cancer was calculated for each 5-year period during 1995-2009. In both men and women aged 60 years or older, age-specific lung cancer mortality rates were generally lower during 2005-2009 as compared with those during 1995-2004. For combined men and women aged 50-79 years, SMR was nearly unity prior to or during introductory phase of CT screening and during early period of implementation; however, it was significantly decreased during 2005-2009, well after the implementation of CT screening, with SMR (95% confidence interval) being 0.76 (0.67-0.86). Results suggest that wide implementation of low-dose chest CT screening may decrease lung cancer mortality in the community 4-8 years after introduction of the screening.
  Lung cancer (Amsterdam, Netherlands) 10/2012; · 3.14 Impact Factor
• Article: Prevalence of Pulmonary Arteriovenous Malformations as Estimated by Low-Dose Thoracic CT Screening.

  Masayuki Nakayama, Takeshi Nawa, Tatsuya Chonan, Katsuyuki Endo, Satoshi Morikawa, Masashi Bando, Yasuhiko Wada, Takanobu Shioya, Yukihiko Sugiyama, Shimao Fukai
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  ABSTRACT: Pulmonary arteriovenous malformations (PAVMs) are rarely encountered in clinical practice. The prevalence of PAVMs associated with hereditary hemorrhagic telangiectasia (HHT) has been estimated based on the rate in the family members of HHT patients, but the prevalence of PAVMs in the general population remains unknown. We retrospectively examined the prevalence and clinical characteristics of PAVMs as detected by a low-dose thoracic CT screening program for lung cancer at the Hitachi Medical Center and the Hitachi General Health Care Center in the northern part of Ibaraki Prefecture, Japan. From 2001 to 2007, we identified eight patients (seven females and one male) with PAVMs among 21,235 initial screening participants (the mean age of the patients with PAVMs and that of the screening participants was 60.6 years). The prevalence of PAVMs was estimated at 38 per 100,000 individuals [95% confidence interval (CI)=18-76]. The diameter of the PAVMs was a mean of 6.6 mm, and none of the lesions could be detected by chest X-ray. Females older than 60 years tended to have larger PAVMs than younger women did (p=0.06). Two patients (25%) were diagnosed with HHT. One patient had previously undergone surgery for a brain abscess. PAVMs are more prevalent than previously reported, especially among females.
  Internal Medicine 01/2012; 51(13):1677-81. · 0.94 Impact Factor
• Article: Indium lung disease.

  Kristin J Cummings, Makiko Nakano, Kazuyuki Omae, Koichiro Takeuchi, Tatsuya Chonan, Yong-long Xiao, Russell A Harley, Victor L Roggli, Akira Hebisawa, Robert J Tallaksen, Bruce C Trapnell, Gregory A Day, Rena Saito, Marcia L Stanton, Eva Suarthana, Kathleen Kreiss
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  ABSTRACT: Reports of pulmonary fibrosis, emphysema, and, more recently, pulmonary alveolar proteinosis (PAP) in indium workers suggested that workplace exposure to indium compounds caused several different lung diseases. To better understand the pathogenesis and natural history of indium lung disease, a detailed, systematic, multidisciplinary analysis of clinical, histopathologic, radiologic, and epidemiologic data for all reported cases and workplaces was undertaken. Ten men (median age, 35 years) who produced, used, or reclaimed indium compounds were diagnosed with interstitial lung disease 4-13 years after first exposure (n = 7) or PAP 1-2 years after first exposure (n = 3). Common pulmonary histopathologic features in these patients included intraalveolar exudate typical of alveolar proteinosis (n = 9), cholesterol clefts and granulomas (n = 10), and fibrosis (n = 9). Two patients with interstitial lung disease had pneumothoraces. Lung disease progressed following cessation of exposure in most patients and was fatal in two. Radiographic data revealed that two patients with PAP subsequently developed fibrosis and one also developed emphysematous changes. Epidemiologic investigations demonstrated the potential for exposure to respirable particles and an excess of lung abnormalities among coworkers. Occupational exposure to indium compounds was associated with PAP, cholesterol ester crystals and granulomas, pulmonary fibrosis, emphysema, and pneumothoraces. The available evidence suggests exposure to indium compounds causes a novel lung disease that may begin with PAP and progress to include fibrosis and emphysema, and, in some cases, premature death. Prospective studies are needed to better define the natural history and prognosis of this emerging lung disease and identify effective prevention strategies.
  Chest 12/2011; 141(6):1512-21. · 5.25 Impact Factor
• Article: Indium-tin oxide does not induce GM-CSF autoantibodies.

  Hironori Masuko, Nobuyuki Hizawa, Tatsuya Chonan, Atsuko Amata, Kazuyuki Omae, Makiko Nakano, Koh Nakata, Akira Hebisawa
  American Journal of Respiratory and Critical Care Medicine 09/2011; 184(6):741; author reply 741-2. · 11.08 Impact Factor
• Article: Long-term prognosis of patients with lung cancer detected on low-dose chest computed tomography screening.

  Takeshi Nawa, Tohru Nakagawa, Tetsuya Mizoue, Suzushi Kusano, Tatsuya Chonan, Shimao Fukai, Katsuyuki Endo
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  ABSTRACT: The effectiveness of lung cancer screening using low-dose chest computed tomography (CT) remains elusive. The present study examined the prognosis of patients with lung cancer detected on CT screening in Japanese men and women. Subjects were 210 patients with primary lung cancer identified on CT screening at two medical facilities in Hitachi, Japan, where a total of 61,914 CT screenings were performed among 25,385 screenees between 1998 and 2006. Prognostic status of these patients was sought by examining medical records at local hospitals, supplemented by vital status information from local government. The 5-year survival rate was estimated according to the characteristics of patients and lung nodule. A total of 203 (97%) patients underwent surgery. During a 5.7-year mean follow-up period, 19 patients died from lung cancer and 6 died from other causes. The estimated 5-year survival rate for all patients and for those on stage IA was 90% and 97%, respectively. Besides cancer stage, smoking and nodule appearance were independent predictors of a poor survival; multivariable-adjusted hazard ratio (95% confidence interval) was 4.7 (1.3, 16.5) for current and past smokers versus nonsmokers and 4.6 (1.6, 13.9) for solid nodule versus others. Even patients with solid shadow had a 5-year survival of 82% if the lesion was 20mm or less in size. Results suggest that lung cancers detected on CT screening are mostly curative. The impact of CT screening on mortality at community level needs to be clarified by monitoring lung cancer deaths.
  Lung cancer (Amsterdam, Netherlands) 08/2011; 75(2):197-202. · 3.14 Impact Factor
• Article: Indium lung--case reports and epidemiology.

  Kazuyuki Omae, Makiko Nakano, Akiyo Tanaka, Miyuki Hirata, Tsutahiro Hamaguchi, Tatsuya Chonan
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  ABSTRACT: The present review is aimed to introduce an new occupational lung disease, Indium Lung. We searched case reports and epidemiological studies concerning indium-related lung diseases and reviewed. Up to March, 2010, 7 cases of interstitial pneumonia in Japanese indium-exposed workers, two cases of pulmonary alveolar proteinosis (PAP) in US indium-exposed workers, one case of PAP in a Chinese indium-exposed worker, and 4 cross-sectional surveys in Japan had been published. All cases and epidemiological studies in Japan indicate that exposure to hardly soluble indium compounds causes interstitial as well as emphysematous lung damages, which we call "Indium Lung". Based on the epidemiological studies, the Japan Society for Occupational Health proposed 3 μg/l of indium in serum as an occupational exposure limit based on biological monitoring to prevent significant increase of KL-6. Long-term follow-up of currently and formerly indium-exposed workers is essential not only to clarify the natural history of indium lung but also to trace the incidence of lung cancer. It is also necessary to elucidate the mechanism of indium lung and difference in clinical manifestations between Japanese and US cases.
  Archiv für Gewerbepathologie und Gewerbehygiene 10/2010; 84(5):471-7. · 1.89 Impact Factor
• Source

  Available from: uoeh-u.ac.jp

  Article: Causal relationship between indium compound inhalation and effects on the lungs.

  Makiko Nakano, Kazuyuki Omae, Akiyo Tanaka, Miyuki Hirata, Takehiro Michikawa, Yuriko Kikuchi, Noriyuki Yoshioka, Yuji Nishiwaki, Tatsuya Chonan
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  ABSTRACT: Recent case reports and epidemiological studies suggest that inhalation of indium dust induces lung damage. To elucidate the dose-dependent effects of indium on the lungs and to prove a causal relationship more clearly. A baseline observation was conducted on 465 workers currently exposed to indium, 127 workers formerly exposed to indium and 169 workers without indium exposure in 12 factories and 1 research laboratory from 2003 to 2006. Indium in serum (In-S) was determined as an exposure parameter, and its effects on the lungs were examined. The means of In-S in the current, former and no exposure workers were 8.35, 9.63 and 0.56 ng/ml, respectively. The current and former exposure workers had significantly higher levels of KL-6, and showed significant dose-dependent increases in KL-6, SP-D, and SP-A. Current exposure workers with In-S of 3 ng/ml or above demonstrated a significant increase of KL-6 in both GM and prevalence exceeding the reference value. Approximately a quarter of the former exposure workers had interstitial changes as seen on chest HRCT. In-S of exposed workers who had been working before improvements of the working environment (Group Bef) and those who started working after improvements (Group Aft) were 12.29 and 0.81 ng/ml, respectively. Adjusted odds ratios indicated 87%, 71% and 44% reductions among Group Aft workers who exceeded the reference values of KL-6, SP-D and SP-A, respectively. Dose-dependent lung effects due to indium exposure were shown, and a decrease of indium exposure reduced the lung effects. An In-S value of 3 ng/ml may be a cut-off value which could be used to prevent early effects on the lungs.
  Journal of Occupational Health 10/2009; 51(6):513-21. · 1.55 Impact Factor
• Article: [Three cases of indium lung].

  Osamu Taguchi, Tatsuya Chonan
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  ABSTRACT: The production of indium tin oxide (ITO) has been increasing during the past decade because of its use in liquid crystal and plasma display panels. Following the first report on lethal lung injury in a ITO worker in 2001, we began pulmonary check-ups for 115 workers in the plant in our capacity of industrial physicians of the plant. Hence, we report interstitial pulmonary disease in 3 workers who had engaged in wet-surface grinding of ITO for 8 to 12 years and had significant lung injuries. The serum indium level and serum concentration of KL-6 were significantly elevated in all 3 cases. One non-smoker case among them showed severe obstructive changes on spirometry and had an episode of repeated bilateral pneumothorax before and during the follow-up period. All 3 cases showed both interstitial and/or emphysematous changes on HRCT. It is suggested that inhaled indium compounds can cause a new and unique interstitial pulmonary disease.
  Nihon Kokyūki Gakkai zasshi = the journal of the Japanese Respiratory Society. 08/2006; 44(7):532-6.