The American Society of Clinical Oncology studied individuals with stage III colon cancer who had undergone surgery and chemotherapy. Those who continued to eat a diet of red meat, fat, and refined grains and sugars were more likely to relapse or die.
They say it means that a person can adjust behavior and avoid or greatly reduce the risk of dying from colon cancer. When you think about it, we humans are really just big digestion machines.
Most of our body seems to be in the business of processing the food we eat. It's just common sense that eating poorly will cause all manner of problems in the gut and elsewhere, but if we need more studies to tell us this, then so be it. Our grandmothers knew it. You are what you eat.