Cough and sputum are not necessarily lung cancer. There are many diseases that present cough and sputum in clinic, such as bronchodilatation, acute bronchitis, chronic bronchitis, lung abscess, tuberculosis and pneumonia. To diagnose whether it is lung cancer or not, you can do CT examination of lung first, if CT of lung suggests that there is occupying lesion, you can further do bronchoscopy examination, and clip the tissues through bronchoscope for pathology examination. If the pathology suggests that there are malignant tumor cells, radiotherapy, chemotherapy or surgery can be given according to the results of the pathology examination.