It has long been known that cancer cells absorb and break down substances in the body differently than healthy, non-cancer cells. This process of absorbing and breaking down substances is known as metabolism and is increased in cancer cells. Recent research suggests that this increased metabolic activity makes it easier for cancer cells to multiply. The objective of the study is to characterize the metabolism of glucose by lung tumors by serum metabolite analysis, using a variant of glucose (sugar) which makes up 1% of glucose in nature.