median OS with right-sided tumours was inferior with first-line anti-EGFR based therapy in comparison to anti-VEGF based therapy (anti-EGFR: 8.7 months [95%-CI: 3.8-NA]; anti-VEGF: 21.8 months [95%-CI: 14.3–58.3]; HR: 3.48 [95%-CI: 2.04–30.28]; p = 0.0027, Fig. 3a) while no difference was shown with left-sided disease (anti-EGFR: 22.1 months [95%-CI: 16.7-NA]; anti-VEGF: 27.2 months [95%-CI: 18.8–39.6]; HR: 1.25 [95%-CI: 0.67–2.40]; p = 0.457; Fig. 3b). This evidence concerns the gene VEGFA and neoplasm.