title: [Results of low-dose computed tomography (LDCT) screening for early lung cancer: prevalence in 4 690 asymptomatic participants].
abstract: OBJECTIVE
  To report the results of low-dose computed tomography (LDCT) screening for early lung cancer in 4 690 asymptomatic participants at the Cancer Hospital, Chinese Academy of Medical Sciences between July 2007 and June 2012.
  
  
  METHODS
  After informed consent and questionnaire forms were obtained, 4 690 asymptomatic participants ≥ 40 years underwent chest low dose spiral CT scanning. According to the National Comprehensive Cancer Network (NCCN) guideline for lung cancer screening (version 1.1, 2012), all participants were assigned to three groups, namely high-risk, moderate-risk and low-risk groups. In terms of gender, smoking history and second-hand tobacco smoking exposure history, two other groups named male and female never-smoker groups who were exposed to second-hand tobacco smoking were designated. The positive results were identified as at least one solid or part-solid nodule measuring ≥ 5 mm, or non-solid nodule ≥ 8 mm in diameter. LDCT scanning protocol, criteria of management according to the size and consistency of pulmonary nodules were compliant with the International Early Lung Cancer Active Program (I-ELCAP). TNM staging of all lung cancers were based on the clinical evidence and pathological findings.
  
  
  RESULTS
  In various risk status group of the participants, the percentage of positive results of baseline CT were 27.0% (86/319), 19.3% (199/1 029) and 11.3% (377/3 342), respectively. A total of 26 participants (27 lesions) were diagnosed as lung cancer (11 in men, 15 in women). The detection rate of lung cancer was 0.6% (26/4 690). Besides a SCLC (limited-disease, LD), 25 cases (76.0%) were stage I including 24 NSCLC and one cacinoid on baseline LDCT and the surgical resection rate was 88.5% (23/26). The diameter of resected cancers was 6.9-29.5 mm (median, 16.3 mm). For female never smokers aged 40 years or older who were exposed to second-hand smoking, the detection rate of lung cancer was higher than that of the high-risk and male never smokers who were exposed to second-hand smoking (1.4% vs. 0.9%, 0.4%).
  
  
  CONCLUSIONS
  The results indicate that LDCT can detect small lung cancers and most of the cancers are detected at an early stage. Emphasis should be placed on the non-smoking female individuals who are exposed to second-hand smoking in China.
authors.affiliation: Department of Diagnostic Radiology, Cancer Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100021, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Tang
authors.affiliation: Email: cjr.wuning@vip.163.com.
authors.forename: Ning
authors.initials: N
authors.lastname: Wu
authors.forename: Yao
authors.initials: Y
authors.lastname: Huang
authors.forename: Jianwei
authors.initials: J
authors.lastname: Wang
authors.forename: Shijun
authors.initials: S
authors.lastname: Zhao
authors.forename: Zhijian
authors.initials: Z
authors.lastname: Xu
authors.forename: Kai
authors.initials: K
authors.lastname: Zhang
authors.forename: Yong
authors.initials: Y
authors.lastname: Jiang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Cai
authors.forename: Lina
authors.initials: L
authors.lastname: Zhou
authors.forename: Meng
authors.initials: M
authors.lastname: Li
authors.forename: Dandan
authors.initials: D
authors.lastname: Tao
authors.forename: Xiaomeng
authors.initials: X
authors.lastname: Liu
authors.forename: Yujie
authors.initials: Y
authors.lastname: Wang
mesh_terms: D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis / Q000453:epidemiology; D002681:China; D055088:Early Detection of Cancer; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000453:epidemiology; D008297:Male; D008403:Mass Screening; D009367:Neoplasm Staging; D015995:Prevalence; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology; D036542:Tomography, Spiral Computed; D014057:Tomography, X-Ray Computed