Preoperative Sequential Short-course Radiation Therapy and FOLFOX for Locally Advanced Rectal Cancer

The treatment protocol proposed in this study is to perform short-term radiation therapy and 4 cycles of FOLFOX chemotherapy for neoadjuvant treatment of locally advanced rectal cancer. Compared to conventional chemoradiation therapy, the preoperative radiotherapy period is shortened, and the cure rate of rectal cancer patients can be improved by early treatment of micrometastasis using systemic chemotherapy. The patients who are assigned to the study group will received the short-course radiotherapy and 4 cycles of FOLFOX and patients in the control will received conventional chemoradiotherapy for preoperative treatment. All patients are recommended to receive total mesorectal excision (TME) after neoadjuvant treatment and adjuvant chemotherapy will be given according to the pathological stage.

Inclusion Criteria:AsianECOG (Eastern Cooperative Oncology Group) performance status 0-2Histologically proven rectal cancer (the lowest border of the tumor located ≤ 10 cm from the anal verge)Histological type: adenocarcinoma, mucinous carcinoma, or signet ring cell carcinomaat least one of the following criteria on pelvic MRI (cTanyN1-2, cT3-4N0, TanymrEMVI (+))MRI scan findings such as pelvic lymph node metastases, sphincter i involvement, (mesorectal fascia) (MRF) (+), and T4b are not exclusion criteria, and are at the discretion of the researcher.Adequate hematologic/renal/hepatic function WBC > 3.0×109/L, Platelet>100×109/L / direct bilirubin<0.4mg/dl / GFR>50ml/min by Wright or Cockroft formula /Patients who listen to and understand the explanation of the study and sign the consent formExclusion Criteria: (one of the following criteria)Colon cancer or rectal cancer located at above the anal verge 10 cmcT1-2N0 on pelvis MRI (magnetic Resonance Imaging)Distant metastasisFamilial Adenomatous polyposisHereditary non-polyposis colorectal cancerSystemic chemotherapy or radiotherapy within 6 monthsHistory of colorectal canceror other type of malignancy within 5 years (Exceptions are made for cured non-melanoma skin cancer or in situ neck cancer.)Patients who are is judged that it is difficult to receive chemotherapy or radiotherapy due to an underlying disease or systemic conditionPatients with bone marrow suppression with neutrophil count < 2 x 109/L and/or platelet count < 100 x 109/L prior to the first chemotherapy administration cyclePatients with peripheral sensory neuropathy with functional impairment prior to the first administration cycle (grade 2 or higher) (peripheral nerve symptoms may worsen)Severe renal dysfunction (GFR ≤30ml/min by Wright or Cockroft formula)Severe hepatic dysfunctionPatients with genetic problems such as galactose intolerance, Lapp lactase deficiency or glucose-galactose malabsorptionPatients receiving Tegafur, Gimeracil, and Oteracil potassium combination drugs and those within 7 days of discontinuationPatients receiving sorivudine or brivudinePatients with a history of another malignant disease within the last 5 yearsPatients with clinically significant heart disease or myocardial infarction within the past 6 monthsA history of hereditary diseases or hemocoagulopathy that pose a risk of bleedingPatients with central nervous system disorders or a history of mental disorders and patients with evidence of central nervous system metastasesPregnant or lactating womenPatients currently participating in other clinical trials or receiving investigational drugsUnhealed wounds, fractures, peptic ulcer, abscesses in the abdominal cavityActive gastrointestinal bleedingActive infections requiring antibiotics for injectionEmergency SurgeryPatients with a history of hypersensitivity reactions to the components of the investigational drugPatients with non-malignant tumor diseasesPatients known to have dihydropyrimidine dehydrogenase deficiencyPatients who do not wish to participate in this study