The multivariable model to predict tumor burden (defined as the sum of the longest tumor diameters [mm]) (which included as predictable factors: liver metastasis, RAS and BRAF mutant/wild-type status at baseline) showed that the presence of RAS or BRAF mutations at baseline was not associated with tumor burden but liver metastasis vs not having liver metastasis was significantly associated with tumor burden (difference of 41.5 mm between them, 95% CI 19.2–63.7; p = 0.0004) (Supplementary Table S5). Here, BRAF is linked to neoplasm.