COPD phenotypes in a lung cancer screening population.

BACKGROUND AND AIMS: COPD (chronic obstructive pulmonary disease) is a very heterogeneous disease, and phenotypic categorization of a high-risk population has many potential benefits. The present study uses a symptom questionnaire, low-dose computed tomography (LDCT) and pulmonary function tests (PFT) to phenotypically subgroup a high-risk population. METHODS: Study group consisted of current or former smokers who underwent lung cancer screening with LDCT as a subgroup of Pittsburgh Lung Screening Study. In addition to LDCT, PFT and a symptom query questionnaire were obtained from each patient. RESULTS: The study group consisted of 3183 subjects (age 50-79) subdivided into eight groups according to presence of symptoms, obstruction on PFT and presence of emphysema on LDCT. A total of 501 (15.7%) subjects were asymptomatic, with no airflow obstruction or evidence of emphysema. There were 866 (27.2%) subjects with both obstruction on PFT and emphysema on LDCT, but only 660 (20.7%) had symptoms. Five hundred thirty (16.6%) of the subjects had no emphysema on LDCT but had obstruction on PFT, although only 370 (11.6%) had symptoms. Four hundred seventy-four (14.9%) of subjects had emphysema on LDCT, but no airflow obstruction, with 312 (9.8%) symptomatic. Finally, 812 (25.5%) of subjects had no evidence of airflow obstruction on PFT or emphysema on LDCT, but had symptoms. CONCLUSION: Combining LDCT with PFT and a comprehensive questionnaire allows subgroup classification of COPD phenotypes in a high-risk population and may lead to earlier intervention and an improved framework for future studies.

The Pittsburgh Lung Screening Study (PLuSS): outcomes within 3 years of a first computed tomography scan.

RATIONALE: The role of computed tomography (CT) screening for lung cancer is controversial, currently under study, and not yet fully elucidated. OBJECTIVES: To report findings from initial and 1-year repeat screening low-radiation-dose CT of the chest and 3-year outcomes for 50- to 79-year-old current and ex-smokers in the Pittsburgh Lung Screening Study (PLuSS). METHODS: Notified of findings on screening CT, subjects received diagnostic advice from both study and personal physicians. Tracking subjects for up to three years since initial screening, we obtained medical records to document diagnostic procedures, lung cancer diagnoses, and deaths. MEASUREMENTS AND MAIN RESULTS: 3,642 and 3,423 subjects had initial and repeat screening. A total of 1,477 (40.6% of 3,624) were told about noncalcified lung nodules on the initial screening and, before repeat screening, 821 (55.6% of 1,477, 22.5% of 3,642) obtained one or more subsequent diagnostic imaging studies (CT, positron emission tomography [PET], or PET-CT). Tracking identified 80 subjects with lung cancer, including 53 subjects with tumor seen at initial screening. In all, 36 subjects (1.0% of the 3,642 screened), referred for abnormalities on either the initial or repeat screening, had a major thoracic surgical procedure (thoracotomy, video-assisted thoracoscopic surgery [VATS], median sternotomy, or mediastinoscopy) leading to a noncancer final diagnosis. Out of 82 subjects with thoracotomy or VATS to exclude malignancy in a lung nodule, 28 (34.1%) received a noncancer final diagnosis. Forty of 69 (58%) subjects with non-small cell lung cancer had stage I disease at diagnosis. CONCLUSIONS: Though leading to the discovery of early stage lung cancer, CT screening also led to many diagnostic follow-up procedures, including major thoracic surgical procedures with noncancer outcomes.

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.