Study of Aprepitant / Fosaprepitant for the Prevention of Chemotherapy-induced Nausea and Vomiting (CINV) in Colorectal Cancer Patients - SENRI Trial

Inclusion Criteria: * Age: ≥20 years old * Sex: Not specified * Patients with colon/rectal cancer who first underwent FOLFOX, XELOX or SOX regimen including oxaliplatin at ≥85 mg/m2 (naive patient), or those who had already started chemotherapy and had nausea of Grade 2 or higher in the last course or an earlier course (non-naive patient). * Stage: not specified (neoadjuvant/adjuvant chemotherapy, advanced or recurrent type are allowed) * Combination of molecular targeted therapy: allowable * Written informed consent for participation in the study. Exclusion Criteria: * Severe liver or kidney disease * Nausea/vomiting within 24 hr prior to chemotherapy. * Treatment with antiemetics within 24 hr prior to chemotherapy. * Presence of factors causing nausea/vomiting other than chemotherapy (e.g. brain tumor, gastrointestinal obstruction, active peptic ulcer disease, brain metastasis) * Presence of a disease precluding 3-day administration of dexamethasone (e.g. uncontrollable diabetes) * Pregnant or lactating women, women who plan to become pregnant. * Current treatment with pimozide. * Any patient judged to be inappropriate for the study by the investigator.