Yes, I'm alive. My pancreas is now calling a medical waste landfill in New Jersey home as it was removed last October. Before I was totally gutted like a fish, 75% of it was removed in August.
With only 25% of a pancreas, my body still produced some insulin & digestive enzymes.
A total pancdretomy (I always misspell this word to the point my spell check won't even give me suggestions) will live your friend a diabetic and his body will no longer produce digestive enzymes. This means he'll need to be careful of his diet, will be insulin dependant, and will need to take digestive enzyme pills when he eats. A person can return to a somewhat normal life style if they eat right, exercise, and take care of themselves. A strong network of support also helps, so your pal is lucky to have you as a friend.
The healing process from a total pancdretomy can be painful. For example, it can take a few months for one's body to remember that food should go down into the stomach instead of coming back up. Delayed Gastric emptying is no fun! I made it a game called Will It Stay Down? As a friend, one of the worst things you can do it give your buddy tips on how to eat if he experiences delayed gastric emptying. For example, no one likes to be told to eat slower, take smaller bits, etc. even if this advice is given out of love. It's not how a person eats that results in delayed gastric emptying. Feeding tubes can also look scary, but they play a pivotal role in recovering if they need to be installed.
As for the chemo, that is the wild card. How and if the cancer has spread outside of the pancreas will play a much bigger factor in a successful recovery than not having all or part of his pancreas.
I wish you the best!