THIS paper presents the findings of a detailed follow-up study of the clinical records of 398 patients suspected of having lung tumor by a roentgenologic review board that interpreted the films of a total of 536,012 persons. It was prepared under the auspices of the medical subcommittee* on nontuberculous diseases of the Boston Chest Survey and conducted with funds provided by the Massachusetts Division of the American Cancer Society. The survey extended from September 15, 1949, to February 1, 1950.An earlier publication† reviewed the organization of the survey and presented statistical information available at that time on the patients . . .