Screening for Small-Cell Lung Cancer: A Follow-Up Study of Patients With Lambert-Eaton Myasthenic Syndrome

Abstract

Purpose A small-cell lung carcinoma (SCLC) is found in 50% of patients with Lambert-Eaton myasthenic syndrome (LEMS). We evaluated screening to optimize screening strategy for SCLC. It is important to detect these tumors early in newly diagnosed patients with LEMS to offer optimal patient treatment. Patients and Methods A large nationwide cohort study of consecutive patients in the Netherlands, seen between 1990 and 2007, were screened for the presence of a tumor using chest x-ray, computed tomography of the thorax (CT-thorax), [18F]fluorodeoxyglucose positron emission tomography (FDG-PET), bronchoscopy, and/or mediastinoscopy. Results SCLC was found in 54 patients, and in 46 patients, no tumor was found during a median follow-up of 8 years (range, 3 to 26 years). All patients with SCLC had a positive smoking history and 86% were still smoking at diagnosis. SCLC was found in 92% of these patients within 3 months and in 96% within a year. At first screening, CT-thorax detected an SCLC in 45 patients (83%), whereas chest x-ray found the tumor in only 23 patients (51%). An SCLC was found during secondary screening in another nine patients (median, 3 months; range, 1 to 41 months). In six patients, a lung tumor was found by CT-thorax or FDG-PET, and in three patients, extrapulmonary metastases were found, initially without identifiable tumor mass on CT-thorax. Conclusion In almost all patients (96%), the SCLC was found within 1 year of diagnosis. CT-thorax scans detected most of the tumors (93%) and was far more sensitive than chest x-ray (51%). FDG-PET may have additive value in selected cases. We propose a screening protocol based on CT-thorax and FDG-PET.