The precision medicine approach for advanced and metastatic colorectal cancer

Abstract It is increasingly obvious that colorectal cancer is a very heterogeneous disease with a multitude of mutational profiles and differing responses to treatment according to site of disease (right versus left), mismatch repair status, RAS and RAF mutational status, site of metastases (e.g. liver versus peritoneum). Therefore it has become increasingly apparent that a ‘one size fits all’ approach to colorectal cancer treatment will lead to poor response rates, increased and futile toxicity, and greater costs to health economies. Therefore there is a great drive to personalize the approach and to generate a precision plan for every individual patient to achieve the best outcomes in terms of longevity and toxic and financial cost. This chapter demonstrates how it is to be hoped that this might be achieved.