Emphysema detected by lung cancer screening with low-dose spiral CT: prevalence, and correlation with smoking habits and pulmonary function in Japanese male subjects.
OBJECTIVE
Screening with low-dose spiral CT is a promising new tool for early lung cancer detection. A study was undertaken to assess the prevalence of emphysema detected by CT screening, and to assess the correlation between the extent of emphysema and the severity defined according to the recently published Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria.


METHODS
After informed consent, CT screening and pulmonary function tests were performed on 615 men between the ages of 40 and 69. Severity of emphysema was assessed visually. Only the pulmonary function data for male subjects were analysed because there were too few female subjects with emphysema.


RESULTS
Emphysema was detected in 30.5% of current smokers, 14.1% of former smokers and 3.0% of non-smokers. In male current smokers, airflow obstruction (FEV(1)/FVC < 0.7) was seen in 18.1% of subjects with mild emphysema, and in 33.3% of subjects with moderate emphysema. FEV(1) values were less than 80% of the predicted normal in 8.5% of subjects with mild emphysema, and 28.6% of subjects with moderate emphysema. The percentage of male subjects with emphysema equivalent to GOLD stage 0 was 90.0% for subjects in their 40s, 82.5% for those in their 50s, and 68.2% for those in their 60s.


CONCLUSIONS
A considerable percentage of the subjects with emphysema as detected by CT screening had GOLD stage 0. CT screening assists in detecting early-stage emphysema.
Japanese Red Cross Kumamoto Health Care Center, Nagamineminami, Kumakoto, Japan. omori@kenkan.gr.jp
Hisamitsu
H
Omori
Rumi
R
Nakashima
Nobuko
N
Otsuka
Yoshiko
Y
Mishima
Seigi
S
Tomiguchi
Akiko
A
Narimatsu
Yoshio
Y
Nonami
Shuichi
S
Mihara
Wasaku
W
Koyama
Tohru
T
Marubayashi
Yasuo
Y
Morimoto
D000328:Adult; D000368:Aged; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000453:epidemiology*; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D015995:Prevalence; D011379:Prognosis; D011656:Pulmonary Emphysema / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000503:physiopathology; D012129:Respiratory Function Tests; D012907:Smoking / Q000009:adverse effects* / Q000453:epidemiology; D036542:Tomography, Spiral Computed