Olanzapine or Dexamethasone, With 5-HT3 RA and NK-1 RA, to Prevent CINV

Inclusion Criteria (Patients are eligible to be included in the study only if they meet all of the following criteria): 1. Cancer patients, age ≥ 18 years and ≤75 years, ECOG score 0-2 points, receiving cisplatin-containing doublet chemotherapy such as cisplatin + gemcitabine / albumin paclitaxel / etoposide /fluorouracil / irinotecan / temozolomide as first line treatment; 2. Life expectancy ≥ 3 months; 3. Leucocytes≥3,000/uL; 4. AST≤2.5 × upper limit of normal; 5. Bilirubin ≤1.5 × upper limit of normal; 6. Serum creatinine ≤ 1.5 × upper limit of normal. Exclusion Criteria (Patients will be excluded if any of the following criteria is met): 1. History of CNS disease, such as brain metastases or epilepsy; 2. Use of other antipsychotic drugs (such as risperidone, quetiapine, clozapine, phenothiazine, or butyrophenone, or such treatment is under scheduling during the study) within 30 days before enrollment; long-term use of phenothiazine as an antipsychotic agent; 3. Concurrent use of pharyngeal or abdominal radiotherapy; 4. Concurrent use of quinolone antibiotics; 5. Chronic alcoholism; 6. Known hypersensitivity to olanzapine; 7. Know arrhythmia, uncontrolled congestive heart failure or acute myocardial infarction within 6 months; 8. Known uncontrolled diabetes mellitus; 9. Vomiting or retching 24 hours before chemotherapy; 10. Use of anti-emesis drugs 48 hours before chemotherapy; 11. Concurrent use of amifostine; 12. Concurrent use of corticosteroids and the only anti-allergic choice is corticosteroids