Neoadjuvant FOLFOXIRI Versus CapeOX Chemotherapy for Local Advanced Rectal Cancer

Inclusion Criteria: * MRI evaluated of T3-4 or N+ rectal cancer; * Pathologically diagnosed of rectal adenocarcinoma; * 18 to 75 years old; * Distance from lower margin of tumor to anus \<15 cm and suitable for anus-preserving resection; * Tumor amenable to radical resection; * Treatment-na?ve patients with no previous systemic chemotherapy, radiotherapy or local excision for treating rectal cancer; * Laboratory requirements conducted within 7 days of starting study treatment: Neutrophil count ≥ 1.5×10\^9/L, Platelet count ≥ 100×10\^9 /L, Hemoglobin ≥ 80 g/L, Serum bilirubin ≤ 24umol/L, Alanine aminotransferase and aspartate aminotransferase ≤ 60 U/L, Serum creatinine ≤ 110 umol/L; * Be capable to receive a surgery; * No second tumor at present or in the past 5 years, except skin basal cell carcinoma, skin squamous cell carcinoma, or any in situ cancer; * No previous systemic chemotherapy for treating colorectal cancer; * Life expectancy of more than 3 months; * No current pregnancy or breast-feeding, and subjects at childbearing age shall take method of contraception; * Eastern Cooperative Oncology Group (ECOG) performance status (PS) ≤ 1; * Be willing and able to understand the study and to provide written informed consent. Exclusion Criteria: * End-stage cachexia patients; * Cardiopulmonary dysfunction or liver and kidney dysfunction, and unable to tolerate chemotherapy or surgery; * Metastatic carcinoma; * Incomplete or complete intestinal obstruction; * Known to be allergic to capecitabine, 5-Fu, oxaliplatin or irinotecan; * Pregnant or lactating women; or women who have fertility but have not taken at taken adequate contraceptive measures; * Have vital organ failure or other severe diseases, including but not limited to coronary heart disease, cardiovascular diseases, or myocardial infarction within 12 months before being included; severe neurological or psychiatric historysevere infection; active disseminated intravascular coagulation; active hepatitis, severe coagulation disorder patients; * History of other malignancy within the past 5 years except effectively treated skin basal cell carcinoma, skin squamous cell carcinoma, or any in situ cancer; * Serious organic disease including but not limited to heart, kidney, brain, and lung.