Very sorry for your loss
I lost one of my best friends to this horrible cancer last year 🙁
He went to the emergency room in late Feb because his co workers noticed his skin was yellowish and the whites of his eyes were yellowish (jaundice). They told him his billup tube between the pancreas and liver was blocked and put in a temporary stint and his color returned to normal but they told him there was a 80% chance he had pancreatic cancer. Two weeks later in March they confirmed a tumor on his pancreas with endoscopic sonogram and started a course of daily radiation treatments in conjunction with very mild chemo.
This continued until June when he got really sick again and they went in again and replace the temp stint with a permenant stint and once again he seemed to get better. He woke up on July 20th throwing up blood and was taken to the hospital where they pumped three bags of blood into him and sent him in for emergency exploratory surgery. He died on the operating table, the doctors said the tumor was leaning on a major artery and eventually ruptured it causing him to bleed out.
This type cancer is such a killer because of where the pancreas lies in the body, it's wedged between the heart, liver and stomach and is surronded by major arteries, because of this something like 80% of tumors on the pancreas are inoperable. Although it is not normally as sudden as in the OP the statistics for this type of cancer are gruesome. It is often not diagnosed until it's too late, 75% of patients die within a year of being diagnosed and 95% die within 5yrs.
If given the choice I think I would rather go suddenly like the OP's sister in law. Although the few months warning gave my buddy some time to settle his affairs and update his will it was an absolutely horrible time for him. He went through shock then denial, then hope which was quickly dashed when the doctor confirmed his tumor was inoperable to utter dispair. I would not wish that on anybody.
