Association of radiographic emphysema and airflow obstruction with lung cancer.

RATIONALE: To study the relationship between emphysema and/or airflow obstruction and lung cancer in a high-risk population. OBJECTIVE: We studied lung cancer related to radiographic emphysema and spirometric airflow obstruction in tobacco-exposed persons who were screened for lung cancer using chest computed tomography (CT). METHODS: Subjects completed questionnaires, spirometry, and low-dose helical chest CT. CT scans were scored for emphysema based on National Emphysema Treatment Trial criteria. Multiple logistic regressions estimated the independent associations between various factors, including radiographic emphysema and airflow obstruction, and subsequent lung cancer diagnosis. MEASUREMENTS AND MAIN RESULTS: Among 3,638 subjects, 57.5, 18.8, 14.6, and 9.1% had no, trace, mild, and moderate-severe emphysema, and 57.3, 13.6, 22.8, and 6.4% had no, mild (Global Initiative for Chronic Obstructive Lung Disease [GOLD] I), moderate (GOLD II), and severe (GOLD III-IV) airflow obstruction. Of 3,638 subjects, 99 (2.7%) received a lung cancer diagnosis. Adjusting for sex, age, years of cigarette smoking, and number of cigarettes smoked daily, logistic regression showed the expected lung cancer association with the presence of airflow obstruction (GOLD I-IV, odds ratio [OR], 2.09; 95% confidence interval [CI], 1.33-3.27). A second logistic regression showed lung cancer related to emphysema (OR, 3.56; 95% CI, 2.21-5.73). After additional adjustments for GOLD class, emphysema remained a strong and statistically significant factor related to lung cancer (OR, 3.14; 95% CI, 1.91-5.15). CONCLUSIONS: Emphysema on CT scan and airflow obstruction on spirometry are related to lung cancer in a high-risk population. Emphysema is independently related to lung cancer. Both radiographic emphysema and airflow obstruction should be considered when assessing lung cancer risk.

Non-cardiac findings on coronary electron beam computed tomography scanning.

The objective of this study was to estimate the prevalence and significance of non-cardiac findings on Electron Beam Computed Tomography (EBT) scanning when used in population screening for the quantitative measurement of coronary artery calcium and estimate of coronary risk. Clinic files of 1366 subjects who underwent EBT scanning between September 1996 and December 1998 at the University of Pittsburgh affiliated Comprehensive Heart Care Center were abstracted. The files of 1356 subjects contained the calcium score and non-cardiac findings as reported by board-certified radiologists, who interpreted the scans during the period 1996-1998. A National Death Index (NDI) Plus match was performed to ascertain cause of death. Two hundred seventy-eight of 1356 (20.5%) subjects had 1 or more non-cardiac findings on EBT scanning. Fifty-seven of 1356 (4.2%) received a recommendation for diagnostic CT follow-up. Forty-six of the 57 recommendations were for pulmonary nodules and 11 were for non-nodule, non-cardiac findings. Seven members of the cohort died during a short follow-up period. In 1 case, the non-cardiac finding was the cause of death. Non-cardiac findings in a healthy cohort referred for EBT coronary screening are relatively common. Findings range from clinically insignificant to the cause of death during a short follow-up period. EBT scanning is a frequently used coronary screening procedure. With the relatively high detection of significant, non-cardiac pathology in this increasingly common screening procedure, consideration should be given for radiologists to interpret the scans.