One thing to remember and ask the doctor/oncologist is about peritoneal carcinomatosis. My hubby was diagnosed what doctors thought early, and he went through chemo and radiation, and then surgery. They opened him up, made all the incisions as if to remove the esophagus, but explored the abdomen to find microscopic seeding there. We had NEVER been told of this possibility, and it shook us to the ground.
Research on the net on cancer and university sites show that this cancer is common for gastric cancers, and has given my husband no chance of survival. He was given 3 months to live after his surgery, but I forced the doctors to give him some more chemo to extend his life. He took 5 months (1 week a month) of 5FU, and that didn't seem to do harm nor good. He has lost a lot of weight, and doctors want to try another type of chemo, but he couldn't because his blood values were too low.
He has to have paracentesis weekly with between 6 and 9 litres drawn each time, and he is almost half the weight he was before diagnosis. He sleeps all the time now, but his personality has changed and he has become cruel, cold and unfeeling, on top of the pity party he enjoys so much.