If cancer of the lung is to be diagnosed at a time when it will still be amenable to some therapeutic measure, it must be diagnosed early. Meakins1 has defined a case of early cancer of the lung as one in which "the original tumour is still localized and has not as yet involved either the peribronchial and mediastinal glands or any other adjacent structures, and before extensive pulmonary, pleural, or distant metastases have occurred." A neoplasm of the bronchial tree, beginning as an invasion of a relatively small part of the bronchial structure, must first produce irritation, erosion, hemorrhage, pressure, infection or obstruction before gross symptoms referable to the thorax will be elicited. The primary growth in such instances will rarely cause pain in the early stages. "The early diagnosis depends on a careful consideration of what often appear to be trivial symptoms."
At present, when cough seems