KRAS and colorectal carcinoma: Association between PIK3CA mutation and survival has been reported in previous studies with differences in the type of mutation or the group of patients: poor survival for all PIK3CA mutations in all colorectal carcinomas by Iida et al and Kato et al [13], [28], for tumors with both exons 9 and 20 mutations only by Liao et al [29], for tumors with exon 20 mutation only by Farina-Sarasquesta et al [32], and in patients with KRAS wild-type tumors only by Ogino et al [18].