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Objectives: Several studies have identified airflow obstruction as a risk factor for lung cancer independent of smoking history, but the risk associated with the presence of radiographic evidence of emphysema has not been extensively studied. We proposed to assess this risk using a quantitative volumetric CT scan analysis.Methods: Sixty-four cases of lung cancer were identified from a prospective cohort of 1,520 participants enrolled in a spiral CT scan lung cancer screening trial. Each case was matched to six control subjects for age, sex, and smoking history. Quantitative CT scan analysis of emphysema was performed. Spirometric measures were also conducted. Data were analyzed using conditional logistic regression making use of the 1:6 set groups of 64 cases and 377 matched control subjects.Results: Decreased FEV(1) and FEV(1)/FVC were significantly associated with a diagnosis of lung cancer with ORs of 1.15 (95% CI, 1.00-1.32; P = .046) and 1.29 (95% CI, 1.02-1.62; P = .031), respectively. The quantity of radiographic evidence of emphysema was not found to be a significant risk for lung cancer with OR of 1.042 (95% CI, 0.816-1.329; P = .743). Additionally, there was no significant association between severe emphysema and lung cancer with OR of 1.57 (95% CI, 0.73-3.37).Conclusions: We confirm previous observations that airflow obstruction is an independent risk factor for lung cancer. The absence of a clear relationship between radiographic evidence of emphysema and lung cancer using an automated quantitative volumetric analysis may result from different population characteristics than those of prior studies, radiographic evidence of emphysema quantitation methodology, or absence of any relationship between emphysema and lung cancer risk. [ABSTRACT FROM AUTHOR]

Background: Although no study has prospectively documented the rate at which lung cancers grow, many have assumed exponential growth. The purpose of this study was to document the growth of lung cancers detected in high-risk participants receiving annual screening chest CT scans.Methods: Eighteen lung cancers were evaluated by at least four serial CT scans (4 men, 14 women; age range, 53 to 79 years; mean age, 66 years). CT scans were retrospectively reviewed for appearance, size, and volume (volume [v] = pi/6[ab(2)]). Growth curves (x = time [in days]; y = volume [cubic millimeters]) were plotted and subcategorized by histology, CT scan attenuation, stage, survival, and initial size.Results: Inclusion criteria favored smaller, less aggressive cancers. Growth curves varied, even when subcategorized by histology, CT scan attenuation, stage, survival, or initial size. Cancers associated with higher stages, mortality, or recurrence showed fairly steady growth or accelerated growth compared with earlier growth, although these growth patterns also were seen in lesser-stage lung cancers. Most lung cancers enlarged at fairly steady increments, but several demonstrated fairly flat growth curves, and others demonstrated periods of accelerated growth.Conclusions: This study is the first to plot individual lung cancer growth curves. Although parameters favored smaller, less aggressive cancers in women, it showed that lung cancers are not limited to exponential growth. Tumor size at one point or growth between two points did not appear to predict future growth. Studies and equations assuming exponential growth may potentially misrepresent an indeterminate nodule or the aggressiveness of a lung cancer. [ABSTRACT FROM AUTHOR]

BACKGROUND: Pulmonary nodules are spherical radiographic opacities that measure up to 30 mm in diameter. Nodules are extremely common in clinical practice and challenging to manage, especially small, 'subcentimeter' nodules. Identification of malignant nodules is important because they represent a potentially curable form of lung cancer. METHODS: We developed evidence-based clinical practice guidelines based on a systematic literature review and discussion with a large, multidisciplinary group of clinical experts and other stakeholders. RESULTS: We generated a list of 29 recommendations for managing the solitary pulmonary nodule (SPN) that measures at least 8 to 10 mm in diameter; small, subcentimeter nodules that measure < 8 mm to 10 mm in diameter; and multiple nodules when they are detected incidentally during evaluation of the SPN. Recommendations stress the value of risk factor assessment, the utility of imaging tests (especially old films), the need to weigh the risks and benefits of various management strategies (biopsy, surgery, and observation with serial imaging tests), and the importance of eliciting patient preferences. CONCLUSION: Patients with pulmonary nodules should be evaluated by estimation of the probability of malignancy, performance of imaging tests to characterize the lesion(s) better, evaluation of the risks associated with various management alternatives, and elicitation of patient preferences for treatment. [ABSTRACT FROM AUTHOR]