Mom Is 75 Life Long Smoker. My Mom First Went

Mom is 75 life long smoker. My mom first went to hospital for afib on July 3 2014. Since that time she has has 7 stays in the hospital.
Right away she went on several bp and heart rate medicines and of course coumiden. They have battled keeping her inr at the correct limits. She has also had severe burning around her ankles and big toe. She has had every test known done to fig. Recently the neurologist said it was basically the same as someone with diabetic neuropathy. Now recently she found blood in her stool and found an ulcer on her duodenum which was bleeding. Her hemoglobin was down to 6.7. She was givin 2 units of blood and stool cleared up and was doing well. They then put her back on coumiden and again she felt terrible. This time she started having terrible back an rib pains. Found blood in stool again and this time gave her 2 units of blood. I know this is all over the place. She has never weighed more than 120 her entire life but between the last 2 hospital stays she lost 8 pounds. My fear in cancer. Bone or pancreatic?? Do u have any thoughts on this rambling