Cancer is multi-aetiologic. There is no one clear-cut causation, but suffice to say, yeast and dysbiosis certainly plays a fundamental role in cancer development. I certainly believe that those with excellent GI function have a much lesser chance of developing cancer, but these positive changes must be of long duration. Cancer does not develop overnight, it is a development which takes time to occur. Those who have maintained excellent dietary and lifestyle habits for many years concurrently have a much smaller chance of oncogenesis than those who drink alcohol regularly, eat hydrogenated fats, convenience and processed foods and who live in prolonged low-grade stressful environments. I guess this means essentially that 1 in 3 people will end up with cancers in the Western world, because only a smaller percentage of people really look seriously at a cancer-proof lifestyle. Too many rely on Western medicine to save their lives once they have developed cancer.