What is the difference between emphysema and lung cancer?

COPD: Is destructive lung disease, divided into chronic bronchitis and emphysems. It is measured by pft's: tests that determmine volumes and speed of moving air. Lung cancer is increased in people with copd, cells have gone awry, travel to other parts of the body causing death by local progression or distant metastasis. Similar cause: tobacco. Mode of death quite different.

Different things: Emphysema is destruction of lung tissue from (most often) smoking. Lung cancer is an abnormal growth of lung tissue that can cause destruction of many tissues, not just lung. They are completely different diseases. But, because the most common cause of lung cancer is smoking, many times patients with lung cancer have emphysema and vice versa.