Propensity score analysis of lung cancer risk in a population with high prevalence of non-smoking related lung cancer.

BACKGROUND: Lung cancer has been the leading cause of cancer-related mortality worldwide among both men and women in recent years. There is an increase in the incidence of nonsmoking-related lung cancer in recent years. The purpose of the present study was to investigate multiple potential risk factors for nonsmoking-related lung cancer among Asian Ethnic Groups. METHODS: We used a propensity score-mated cohort analysis for this study. We retrospectively review the medical record of 1975 asymptomatic healthy subjects (40 ~ 80 years old) who voluntarily underwent low-dose chest CT from August 2013 to October 2014. Clinical information and nodule characteristics were recorded. RESULTS: A propensity score-mated cohort analysis was applied to adjust for potential bias and to create two comparable groups according to family history of lung cancer. For our primary analysis, we matched 392 pairs of subjects with family history of lung cancer and subjects without history. Logistic regression showed that female gender and a family history of lung cancer were the two most important predictor of lung cancer in the endemic area with high prevalence of nonsmoking-related lung cancer (OR = 11.199, 95% CI = 1.444-86.862; OR = 2.831, 95% CI = 1.000136-8.015). In addition, the number of nodules was higher in subjects with family history of lung cancer in comparison with subjects without family history of lung cancer (OR = 1.309, 95% CI = 1.066-1.607). CONCLUSIONS: In conclusion, risk-based prediction model based on the family history of lung cancer and female gender can potentially improve efficiency of lung cancer screening programs in Taiwan.

Ambiguous presentation of Mycobacterium avium complex-associated Rasmussen aneurysm.

A 77-year-old man with a progressively dry cough (two months duration) was admitted with hemoptysis. Chest computed tomography (CT) revealed left lingular lobe consolidation and one thick-walled cavity lesion over the left lower lobe, which was accompanied by satellite micro-nodules in a tree-in-bud pattern. CT-guided biopsy confirmed mycobacterial infection, and subsequent culture yielded Mycobacterium avium complex (MAC). Unremitting hemoptysis was present despite treatment (14 days) with ethambutol, rifampin, clarithromycin, and streptomycin. Initial CT angiography (CTA) to determine the source of the hemoptysis revealed a suspected aneurysm in the consolidated left lingular lobe; however, this could not be localized via catheter angiography during the pulmonary and bronchial arterial phases. Two weeks later, a massive hemoptysis episode led to haemodynamic instability and serious consequences. Follow-up CTA confirmed the previously detected aneurysm, and glue embolization was performed successfully. This case report highlights a rare but catastrophic MAC-associated pseudoaneurysm and relevant treatment options.