PIK3CA and colorectal carcinoma: While all patients had stage IV disease at study enrollment, 384 (59.0%) were initially diagnosed with stage IV CRC and the remainder were diagnosed with earlier stage disease, which progressed prior to enrollment; 49% had tumors with wild-type KRAS, 77% had tumors with wild-type PIK3CA, 44% had a tumor located on the left-side of the colon.