Pancreatic cancer occurs when malignant cells develop in parts of the pancreas. The pancreas is part of both the digestive system and the endocrine (hormone-producing) system. It is a long, flat gland about 13-15cm long that lies between your stomach and spine. 

If your doctor suspects you have pancreatic cancer, you will need a number of tests to confirm the diagnosis. Together, the tests will show what type of pancreatic cancer it is, where in the pancreas it is, and whether it has spread to nearby organs or other parts of the body. Test may include blood tests, a CT scan and other imaging tests, endoscopic tests and tissue sampling (biopsy). source: Cancer Council Victoria