KRAS and neoplasm: In contrast to these data, others have reported a discordance of KRAS mutation status in primary tumours and metastatic sites, with an overall discordance observed in 4–32% of the patients (Oudejans et al, 1991; Al-Mulla et al, 1998; Albanese et al, 2004; Oliveira et al, 2007; Artale et al, 2008; Santini et al, 2008; Cejas et al, 2009; Garm Spindler et al, 2009; Loupakis et al, 2009; Molinari et al, 2009; Perrone et al, 2009; Baldus et al, 2010; Italiano et al, 2010).