Outcome of patients with lung cancer detected by mass screening versus presentation with symptoms.

Lung cancers in the early stages are frequently detected via mass screening in Japan. The aim of this study is to evaluate the outcome of patients with lung cancer detected via mass screening and to compare them to those in whom the malignancy was detected by symptoms. A total of 774 untreated patients with lung cancer who were admitted to Department of Respiratory Medicine, Tsukuba University Hospital over a 20 year period up to 1995, were analyzed with reference to their reasons for detection of the cancer. In the mass screened group(116 patients), 50.0% of lung cancer was detected at stage I of TNM classification, while only 8.2% of patients with symptoms(561 patients) had stage I lung cancer (p = 0.0001). As lung cancers detected via mass screening were more often at operable stage (stage I, II or IIIA) (p = 0.0001), surgical treatment was chosen more frequently in the mass screened group(p = 0.0001). The outcome of patients with lung cancer detected via mass screening was more favorable than that of the patients detected by their symptoms (p = 0.0002). The early detection of lung cancer via mass screening contributes to improvement of the outcome.