Cox proportional hazards model was used to assess prognostic and predictive role of PIK3CA mutation, adjusting for clinical features and status of routine standard molecular pathology features, including KRAS and BRAF mutations and microsatellite instability (mismatch repair deficiency).All statistical tests were two-sided.
Our data suggested that activation of the PI3K signalling pathway in gastric cancer may be achieved through up-regulation or mutation of PIK3CA, in which the latter may be a consequence of mismatch repair deficiency.