My 83 year old  dad was diagnosed with pancreatic cancer with liver mestasis in January. At first very sleepy,  he now has very few symptoms and has not been sleeping at all. Is it common for symptoms  to come and go? 

He was told he might possibly live to his birthday on March 2nd but has passed that. He has also had heart failure and failing kidneys for the past 4 years.  It's a mystery as to how he is holding out. Any suggestions please?