Supplementary Material for: Clinicopathological significance of APC mutation in patient with colorectal cancer

Introduction: In colorectal cancer (CRC), the prognostic significance of Adenomatous polyposis coli (APC) mutations remains controversial. We aimed to investigate the effect of APC mutations on the prognosis of patients with CRC and to elucidate the clinicopathological features associated with these mutations. Methods: Formalin-fixed, paraffin-embedded CRC specimens were tested for APC mutations using targeted next-generation sequencing, mismatch repair (MMR) deficiency was evaluated using immunohistochemical staining. Clinicopathological features were obtained from medical records and through a review of hematoxylin and eosin slides. Results: APC mutations and MMR deficiencies were detected in 72.8% and 8.9% of the patients with CRC, respectively. APC mutations were significantly correlated with male sex (P = 0.046) and left colon cancer (P < 0.001). They were inversely correlated with age (P = 0.020), serum 19-9 elevation (P = 0.047), distant metastasis (P = 0.005) and MMR deficiency (P < 0001). In univariate analysis, APC mutations correlated with longer overall survival in patients with CRC. Conclusions: APC mutations are associated with favorable prognostic factors and longer overall survival. Further investigation is needed to understand the mechanisms of association between APC mutations to favorable cancer prognosis and their correlation MMR protein expression.