What is the reason that pancreatic cancer is incurable?

Detected late: It is often detected late because it doesn't cause symptoms in it's earliest stages. In addition, chemotherapy doesn't kill the cancer cells very effectively.

It is not incurable: Sometimes it is curable. It depends on what type of cancer it is (some have a better cure rate than others) also it depends on the location of the cancer and how it was diagnosed. Pancreas cancer is notorious for being discovered late because of a lack of symptoms. If it has invaded blood vessels, other organs or distant lymphnodes the chance of cure is very poor. Also most patients would...

Continued: Would require chemotherapy and or radiation therapy after surgery (again this would depend on the type of pancreas cancer).