My mother may have gallbladder cancer. what is the chance of it spreading outside of the gallbladder?

Well they thought my dad's gallbladder was bad and they had him scheduled for the new simple surgery they have now for that where they extract it through the belly button. But when they went in..they found everything was full of cancer and it was Stage 4 and it was everywhere. 1 month later he was gone. Have them do a very very throuough x-ray!