My brother in law passed due to Liver cancer. His was to far along for any treatment by the time he went to hospital.
So we stayed till he passed.

I'm sure everyone is different.
But for him his mid section was swollen and very tender,
he needed help to get upright due to it. all he would eat was watermelon and a few sips for fluid.
I don't know what his pain level was but he refused to take anything other than a relaxant.
Once he was too weak to get up to go potty even with helpers , it was only a day or 2 til the end.

One hospice lady said the bottoms of feet will darken /blacken when it is very close, but I looked at his feet to observe morn/night and didn't see any changes. So i don't know if that is a old wives tale or not.

One thing I did notice with my aunt also, it seems they are more active/lucid the day or 2 before the end. Very quiet the day of..
But that is only 2 instances I can relate so I don't really know...