All patients with diagnosed lung cancer (International Classification of Diseases codes 162.0–162.9) between January 1, 1992, and December 31, 1996, were identified from the NEMC cancer center database. An Asian patient was defined as one who was born in the continent of Asia and had immigrated to the United States. Ninety-five percent of the Asian patients with lung cancer identified in this study had emigrated to the United States from China. Each Asian patient with lung cancer (case) was matched for age and sex with a non-Asian patient with lung cancer who also received a diagnosis of lung cancer in the same 5-year period (control). To reduce selection bias, each case was randomly matched using a computerized randomization program with one of five potential controls identified by the matching process. The following data were abstracted from the medical record (both paper and electronic) of each case or control by two of the authors (G.A.F. or A.C.W.): age, sex, the presence of pulmonary symptoms (ie, cough, dyspnea, hemoptysis, or chest pain), constitutional symptoms (ie, weight loss, anorexia, night sweats, fever, and fatigue), smoking history, time elapsed from diagnosis to start of treatment, testing utilized as part of staging (CT of chest, abdomen, and head; mediastinoscopy; bone scan; MRI of the head or spine; thoracentesis; and pleural biopsy), lung cancer histology, treatment course (surgery alone, chemotherapy alone, local radiation, and combination therapy or no treatment), survival from time of diagnosis to January 1999 (recorded in months), FEV1 (obtained within 1 month of diagnosis), serum albumin and protein concentrations, country of birth, and need for interpreter. Spirometry was performed using a SensorMedics 2450 spirometer (SensorMedics; Yorba Linda, CA). The TNM staging classification for lung cancer in use during the study period was used to stage lung cancer.6 We used the older TNM staging classification, as it was in use during the period of time used for the study and therefore determined patient treatment. For each patient, the clinical stage at presentation was identified from the database and was confirmed by analysis of chest CT scans. Pathologic stage data were obtained in all patients who underwent surgical resection of lung cancer. Outcome data were obtained from either the patient’s medical records or from the Registry of Vital Records in the City of Boston.