Kim performed an analysis of two phase II trials [39] and concluded that preoperative concurrent chemoradiotherapy plus cetuximab did not improve short- or long-term therapeutic outcomes in patients with locally advanced rectal cancer and that KRAS, BRAF and PIK3CA mutations cannot predict the pathological remission rates or disease-free survival (DFS) rates of patients with the disease. This evidence concerns the gene KRAS and rectal cancer.