Hello foxs2112, I'm sorry to hear about your granddad's diagnosis. Unfortunately, the doctor is correct in that the treatment would be too harsh given his age and overall health considering that he has two terminal illnesses; stomach cancer and leukemia. Also, if one doctor stated that your grandfather has only weeks while the other doctor stated months, chances are that your grandfather only has weeks to months. I would definitely take their advice and keep your grandpa comfortable. You may not realize this and he might not admit it but he's had a long life and is probably tired. My dad was only 78 when he was diagnosed with stage 4 lung cancer, and from diagnosis to death was only 17 weeks. My dad also had dementia (a second terminal illness). We chose not to pursue aggressive treatment as we did not want dad to endure the poisonous chemotherapy and the harsh side effects from it. I would advise you to make the best of the limited time that you have left with him, and be thankful for all of the time you had with him.  God bless you and your family. Pray and trust in God's plan.