Neoadjuvant FOLFOXIRI Chemotherapy Alone for Locally Advanced Rectal Cancer

Inclusion Criteria * Diagnosis of adenocarcinoma of the rectum * Age: 18-70 years old * Signed informed consent; able to comply with study and/or follow- up procedures * Stage of the primary tumor may be determined by ultrasound or MRI * Stage II (T3-4, N0 \[N0 is defined as all imaged lymph nodes \< 1.0 cm\]) OR stage III (T1-4, N1-2 \[with the definition of a clinically positive lymph node being any node ≥ 1.0 cm\] * Tumor palpable by digital rectal exam OR accessible by proctoscope or sigmoidoscope * Distal border of the tumor must be located \< 12 cm from the anal verge * Tumor amenable to curative resection * Adequate bone marrow, hepatic and renal function as assessed by the following laboratory requirements conducted within 7 days of starting study treatment: * Leukocytes ≥ 3.0 x109/ L, absolute neutrophil count (ANC) ≥ 1.5 x109/ L, platelet count ≥ 100 x109/ L, hemoglobin (Hb) ≥ 9g/ dL. * Total bilirubin ≤1.5 x the upper limit of normal (ULN). * Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 5 x ULN. * Alkaline phosphatase limit ≤ 5x ULN. * Amylase and lipase ≤ 1.5 x the ULN. * Serum creatinine ≤ 1.5 x the ULN. * Calculated creatinine clearance or 24 hour creatinine clearance ≥ 50 mL/ min. * No renal disease that would preclude study treatment or follow-up * ECOG status: 0～1 Exclusion Criteria: * Hypersensitivity to fluorouracil, oxaliplatin or irinotecan. * No More than 4 weeks since prior participation in any investigational drug study * More than 4 weeks since prior participation in any investigational drug study * Clear indication of involvement of the pelvic side walls by imaging * With distant metastasis * History of invasive rectal malignancy, regardless of disease-free interval * Fertile patients must use effective contraception * Uncontrolled hypertension * Cardiovascular disease that would preclude study treatment or follow-up * Lack of upper gastrointestinal tract integrity or malabsorption syndrome，active upper gastrointestinal tract bleeding * Synchronous colon cancer * Pregnant or nursing, Fertile patients do not use effective contraception * Other malignancy within the past 5 years except effectively treated squamous cell or basal cell skin cancer, melanoma in situ, carcinoma in situ of the cervix, or carcinoma in situ of the colon or rectum * No psychiatric or addictive disorders, or other conditions that, in the opinion of the investigator, would preclude study participation * patients refused to signed informed consent.