“…10,13,27,28 This contrasts the effect of KRAS mutations in mCRC 4,29,30 ; possibly due to the small sample sizes of the oesophagogastric trials and relative rarity of KRAS, BRAF and PIK3CA mutations 31,32 It is, therefore, plausible that these uncommon mutations do confer resistance to anti-EGFR antibodies in oesophagogastric cancer, but that this effect has been masked by both the low prevalence of the mutations and co-administration with chemotherapy.…”