Basics in molecular evolution of colorectal cancer and their implications for the surgeon: is it a 'big-bang' or a 'survival of the toughest'?

Multi disciplinary management of cancer has enabled a comprehensive involvement of clinicians in disease
management. For the surgeon involved in colorectal cancer (CRC) management it is pertinent to possess a basic knowledge in tumour biology for effective participation. Several models exist to explain the intra tumour heterogeneity (ITH) seen in cancers; clonal expansion, big-bang theory and the cancer stem cell theory. All of these aim to describe the extreme variability seen within cell populations in solid tumours and their implications on clinical management. This review aims to provide the practising surgeon a basic
knowledge of colorectal tumour biology and their implications in clinical phenomena.