I am sorry to hear about your brother. I have a brother, who had stomach cancer, three times surgery, 21 cyles of Chemos, he lasted 2 and a half years.-, passed away in 08/07. Looking back in two and a half years ago, I noticed somethings could have changed his fate.
First, he did not have a good first surgery, since the infections occurred after two weeks, that made him delayed for his Chemo therapy. this we can not control, only pray.
Second, after he was stable, he should have a right diet for cancer patient, not just ate what he want, follow guidelines of Dr. Randy Pausch ( you can go on line and watch his video, he also has pancrea cancer).
Make sure he keep a good insurance like PPO if he had.
During his Chemo Therapy, my brother only had me as a care giver, lack of family supports can lead to cancer recurrance.
You may look into another help in herbal remedy, you have to hang tough to walk him through this.
God bless him and you.