THE INCREASING urgency of the problem of primary bronchogenic carcinoma of the lung is attested to by Cameron's 1953 annual report to the American Cancer Society, which indicates that at the present time lung cancer is very close to, if not the leading cause of, death from cancer, and that, at least as an officially listed cause of death in vital statistics, it is increasing at an alarming rate (Table 1). How much of this increase is real and how much is due to more accurate diagnosis is a matter chiefly of academic interest. From a practical point of view, the important thing is that the diagnosis and treatment of cancer of the lung is today a real problem in the practice of medicine. For 10 years there have been in the literature more and more papers on this subject, and one of the chief burdens of these papers has