I was under the impression that Jobs did nothing for his cancer. He did, in fact, have it surgically removed.
He further underwent several surgeries for various problems after the pancreatic cancer diagnosis.
It's not clear to me that a doctor wouldn't have advised against chemo for the pancreas. Chemo doesn't always get recommended for cancer treatments (especially now-a-days) and it's not shocking to me that a doctor would potentially recommend against it in his case (super early detection with apparently successful surgery).
A little bit like how if you get skin cancer the first line of defense is to simply lop the thing off. You almost never get chemo with skin cancer unless it has progressed.
The current 5 year survival rate for pancreatic cancer detected early is 80%. So it's definitely an aggressive cancer even in the best practical scenarios.