APR: Abdominoperineal resection; LAR: Low anterior resection; LN: Lymph node; mtLNR: Metastatic lymph node ratio; OS: Overall survival; DFS: Disease-free survival; LVI: Lymphovascular invasion; PNI: Perineural invasion; CEA: Carcinoembryonic antigen; CA19-9: Carbohydrate antigen 19-9; TNM: Tumor, node, metastasis. This evidence concerns the gene CEACAM5 and neoplasm.