The overwhelming majority of the risk in the causation of cancer is NOT genetic. This holds true even for breast cancer where we often think of the BRCA1 gene as a ‘breast cancer death sentence’. In fact, this only accounts for an underwhelming 27% of risk. This holds true for all cancers. For most cancers the attributable risk is only 20–30%. Environmental risk factors accounts for the majority of risk in all cases of cancer.