IRCT2016082129403N2 IRCT 2016-09-24 Vice chancellor for research, Shiraz University of Medical Sciences Effect of preoperative chemotherapy in the treatment of patients with locally advanced rectal cancer Study of efficacy and safety of neoadjuvant chemotherapy with CAPOX regimen and neoadjuvant chemoradiation in complete pathologic responce in locally advanced rectal cancer 2016-07-22 anticipated 40 Complete https://irct.ir/trial/23645 interventional Randomization: N/A, Blinding: Not blinded, Placebo: Not used, Assignment: Single, Purpose: Treatment. 2 Rectal cancer. All patients will receive one course of chemotherapy with CAPOX regimen consisted of infusional Oxaliplatin 130 mg/m2 first day and oral capecitabine, 2000 mg/m2 twice daily during first to 14th days. after 3 weeks this treatment will be followed by chemoradiation included conventional external beam radiotherapy using megavoltage linear accelerator photons. A total dose of 45 Gy external beam radiotherapy will be delivered via a daily fraction of 1.8 Gy, with five fractions per week. Concurrent chemotherapy consisted of oral capecitabine, 825 mg/m2 twice daily during the whole period of the radiotherapy with weekend breaks (Tuesdays and Fridays). Then will receive 2 course of chemotherapy with CAPOX regimen with 3 weeks interwall. All patients will undergo standard surgery 6 weeks after completion of chemoradiation. Pathologic response will be defined through pathologic examination. Treatment-related complications will be determined according to the Common Terminology Criteria for Adverse Events (version 4.0). The endpoints of this study include pathological complete response rate and adverse events (gastrointestinal toxicity)..