Evidence-Based Medicine, Human Studies Ethics, and the ‘Gonzalez Regimen’: a Disappointing Editorial in the Journal of Clinical Oncology Part 2
NB: If you haven’t yet read Part 1 of this blog, please do so now; Part 2 will not summarize it.
At the end of Part 1, I wrote:
We do not need formal statistics or a new, randomized trial with a larger sample size to justify dismissing the Gonzalez regimen.
In his editorial for the JCO, Mark Levine made a different argument:
Can it be concluded that [the] study proves that enzyme therapy is markedly inferior? On the basis of the study design, my answer is no. It is not possible to make a silk purse out of a sow’s ear.
That conclusion may be correct in the EBM sense, but it misses the crucial point of why the trial was (ostensibly) done: to determine, once and for all, whether there was anything to the near-miraculous claims that proponents had made for a highly implausible “detoxification” regimen for cancer of the pancreas. Gonzalez himself had admitted at the trial’s inception that nothing short of an outcome matching the hype would do:
DR. GONZALEZ: It’s set up as a survival study. We’re looking at survival.
SPEAKER: Do you have an idea of what you’re looking for?
DR. GONZALEZ: Well, Jeff [Jeffrey White, the director of the Office of Cancer Complementary and Alternative Medicine at the NCI—KA] and I were just talking a couple weeks ago. You know, to get any kind of data that would be beyond criticism is—-always be criticism, but at least three times.
You would want in the successful group to be three times — the median to be three times out from the lesser successful groups.
So, for example, if the average survival with chemo, which we suspect will be 5 months, you would want my therapy to be at least — the median survival to be at least 15, 16, 17 months, as it was in the pilot study.
We’re looking for a median survival three times out from the chemo group to be significant.
Recall that the median survival in the Gonzalez arm eventually turned out to be 4.3 months.