Secondary lung cancer. Gross specimen of metastatic malignant (cancerous) tumours (white and grey) on the surface of a lung. A metastatic tumour is a secondary cancer that has spread (metastisised) from the site of the original cancer. Small single tumours can sometimes be removed surgically, however, once a cancer has spread the prognosis is poor. Radiotherapy and anti-cancer drugs can slow the cancer's progress and extend the patient's life.