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.
384,845 Helpful Votes. A. Blood urea nitrogen (BUN) is a product of metabolism that is excreted in the urine. It is measured in the blood as an indirect measure of how well the kidney is functioning. Increased BUN levels in the blood may indicate early kidney damage, meaning the kidneys aren't effectively excreting BUN.