For most types of cancer, a biopsy is the main way doctors diagnose cancer. A biopsy is the removal of a small amount of tissue for examination under a microscope. Other tests can suggest that cancer is present, but only a biopsy can make a definite diagnosis. Your doctor may recommend a biopsy if something suspicious is found during a physical exam or another test.
Blood urea nitrogen - BUN - is a blood test performed as a marker of kidney function. It is part of the basic metabolic panel done for health screening. It is also used to monitor the progression of kidney failure. BUN is produced by the breakdown of protein and usually cleared from the blood by the kidneys.
BUN is the abbreviation of blood urea nitrogen and refers to the urea nitrogen in blood. Urea nitrogen is the end production of protein, so the more protein we eat, the higher the urea nitrogen level in blood.