It very likely would have cured his particular form of it.

No, he didn't avoid it, but according to the article, he also didn't avail himself of it until it was clear to him that his "alternative therapy" was not having an appreciable effect. The delay in effective treatment incurred by this poor judgment could easily have cost him his life, or at least prevented him from enjoying several more years of relative comfort.

The article suggests he avoided doing it until it was obvious his body was failing; this removing any advantage that early detection brought him.