There is nothing I can add to the discussion of the technological and cultural legacy of Steve Jobs, who died on October 5th of probable complications of pancreatic cancer and liver transplant. He was a dynamic visionary who gave us the iPod, iPhone, and iPad. He also was the vision behind my favorite movie studio – Pixar.

Others who are in a better position to judge than I have called him the most successful CEO. He certainly made the world a more interesting place, and it is tragic that we lost his vision prematurely.

I debated whether or not to discuss his medical illness. He clearly wanted to keep the details of his health private. But at the same time he was a public figure, and there is already a great deal of discussion and speculation about his illness and treatment. I thought I would clarify a few points.

Jobs was found to have a pancreatic tumor in 2003 on a routine abdominal scan. Fortunately for him, on biopsy the tumor was found to be the rarer but more treatable form of pancreatic cancer. There are two basic types of pancreatic cancer – the more common is adenocarcinoma. This is one of the worst types of cancer to get. Survival rates depend on how advanced the cancer is when diagnosed, but essentially mean survival, even with best treatment is about one year.

The other type, the type Jobs had, represents about 5% of pancreatic tumors and are called endocrine tumors or islet cell tumors. With treatment the 5 year survival (also depending on how advanced it is) is 70-90%, and many patients can live 10 years or more.

The primary treatment is resection – surgical removal of the tumor. The prognosis is greatly dependent on how early the tumor is found, and if it can be removed before it spreads. Jobs was lucky in that his tumor was found early, and his prognosis with treatment was apparently very good.

We know that Jobs has a Whipple procedure in 2004, which removes the pancreas some surrounding structures, like part of the stomach and the small intestine. This probably means that the tumor was in the head of his pancreas, or that there was evidence that it had spread. We also know that after this surgery Jobs was upbeat and reported that he was essentially cured.

We also know that in 2009 Jobs had a liver transplant. It is not clear why this was done, but it is likely that it was to treat cancer recurrence. He also went to Switzerland in that year for an experimental treatment that involves some type of hormone delivered radiation.

There are many questions about Jobs’ illness and treatment that are not publicly known, and there is much speculation about some of the details. Perhaps we will learn these details in the next few months, especially with a biography coming out.

One specific detail that has been the focus of much discussion, especially in skeptical circles, involves the early course of his treatment. A 2008 Fortune article claims that Jobs delayed surgery for 9 months after his initial diagnosis in order to pursue a diet-based treatment:

Yet to the horror of the tiny circle of intimates in whom he’d confided, Jobs was considering not having the surgery at all. A Buddhist and vegetarian, the Apple (AAPL, Fortune 500) CEO was skeptical of mainstream medicine. Jobs decided to employ alternative methods to treat his pancreatic cancer, hoping to avoid the operation through a special diet – a course of action that hasn’t been disclosed until now.

If this is true, then the next question is – what effect did this have on his prognosis. We do not have enough information to answer that question. We can only answer it in general terms. It is possible that the delay had a negative effect on his prognosis, but we would need to know the details of his tumor to say definitively. His doctors likely know the answer to this, but it has not been made public.

That is all I really want to say about the issue for now. I will follow the story if more details come out, and can discuss Jobs’ illness and treatment at a later time. But I will point out that the anti-science vultures are already descending to exploit Jobs’ high profile illness and death to take swipes at science-based medicine.

First and chief among them is Mike Adams at NaturalNews. Orac has already done a great take down of his absurd and fact-free claims. There are many others who are claiming that Jobs was either killed by conventional therapy or could have been saved by alternative cancer therapy – all dubious claims without a shred of evidence.

There has also been a bit of controversy over Brian Dunning’s treatment of the case at Skeptic Blog. Brian took the Fortune article, which he referenced, at face value, which is reasonable as it was a mainstream journalist account without any refutation (as far as I can find). But he also speculated about the medical facts that have not been publicly established. He did express caution in his interpretation, but could have emphasized our current uncertainty more. (So a couple more caveats would have fixed what was otherwise a reasonable piece.)

I prefer to wait for sufficient details to become publicly established, that way if there is a cautionary tale to be learned, it will not be blunted by factual uncertainty.

Meanwhile I prefer to celebrate what the man accomplished in the time that he had. This too is a complex legacy – but I really love my iPad, and that fact seems to loom large in my current reaction to the new of his loss.