Metastatic colorectal cancer is a heterogeneous disease. Tumours arising from different regions of the colon are clinically and molecularly distinct. The differing molecular characteristics translate into a differential clinical outcome with right-sided tumours displaying a worse prognosis compared to left-sided tumours. Besides the prognostic relevance of the primary tumour location, several retrospective analyses suggest that the primary tumour location may also be predictive of treatment benefit from targeted therapy with anti-EGFR and anti-VEGF directed agents in the first-line treatment of RAS wild-type metastatic colorectal cancer.

(BELG J MED ONCOL 2018;12(6):271–274)