Oral Steroids for Regorafenib-induced Fatigue/Malaise in Unresectable mCRC (KSCC1402/HGCSG1402)

Inclusion Criteria:

* Capable of granting informed consent in writing for receiving treatment outlined in this protocol
* The investigators determines that the patient can receive the treatment outlined in this protocol
* Histological diagnosis of adenocarcinoma of either the colon or the rectum, regardless of RAS mutation
* Metastatic colorectal cancer scheduled for treatment with regorafenib
* Lesions are either measurable or non-measurable according to RECIST ver. 1.1
* Contrasted torso CT within 28 days before enrollment
* At least 20 years of age
* PS 0-1
* Bone marrow, hepatic, and renal functions have all been confirmed as normal within 14 days prior to initiation of regorafenib treatment
* Life expectancy of at least 3 months

Exclusion Criteria:

* Used regorafenib previously
* Blood transfusion or granulocyte-colony stimulating factor (G-CSF) administration within 14 days
* Grade 2 or higher fatigue or malaise or asthenia according to NCI-CTCAE ver. 4.0
* History of a different type of cancer according to histological findings or cancer of a different primary focus within the past 5 years. The following are excluded: carcinoma in situ of the cervix, non-melanoma skin cancer, superficial bladder cancer (Ta, Tis, and T1), gastric cancer,non-invasive breast cancer, etc
* Highly invasive surgery, an open biopsy, or who have received significant trauma within 28 days of initiating regorafenib treatment
* Congestive cardiac failure of New York Heart Association (NYHA) \>=Class 2
* Unstable angina (symptoms at rest),new-onset angina (onset within past 3 months), or a history of myocardial infarction within 6 months of initiating treatment
* Arrhythmia requiring treatment with anti-arrhythmia drugs
* Uncontrollable hypertension
* Pleural effusion or ascites causing dyspnea (NCI-CTCAE \>=Grade 2)
* History of venous or arterial thrombosis or embolism within 6 months prior to initiation of treatment, including cerebrovascular accidents, deep vein thrombosis, or pulmonary embolism
* Patients with active infections of NCI-CTCAE \>=Grade 3
* Positive for either hepatitis B (HB)s antigen or hepatitis C virus (HCV) antibody
* Seizure disorders requiring drug treatment
* Cerebral metastases or history of such
* History of organ transplant
* Symptoms or history of hemorrhagic tendency, regardless of severity
* Some form of hemorrhaging (NCI-CTCAE \>=Grade 2) within 4 weeks prior to initiating treatment
* Incurable wound, fracture or ulcer
* Renal failure requiring either hemodialysis or peritoneal dialysis
* Dehydration symptoms of NCI-CTCAE \>=Grade 1
* Abusing drugs or who are in a physical, psychological, or social state which might impair study participation or evaluation of results
* Interstitial lung disease with active signs or symptoms
* Have difficulty taking oral drugs
* Digestion absorption disorders
* Adverse events resulting from previous treatments or procedures which have not yet resolved (NCI-CTCAE \>=Grade 2)
* Received systemic anti-cancer treatments within 2 weeks prior to initiation of regorafenib treatment, including chemotherapy, molecular target drugs, immunotherapy, or hormone therapy
* Poorly controlled glucose tolerance abnormalities due to diabetes mellitus (patients using insulin)
* Active GI ulcers or a history of such
* Glaucoma
* Oral steroids are otherwise contraindicated
* Either pregnant or nursing. Women who may become pregnant must have a negative pregnancy test within 7 days prior to initiating treatment
* Women who may become pregnant, or men whose partners may become pregnant, must agree to use appropriate contraceptives from granting of consent to 3 months after conclusion of regorafenib therapy
* Other illnesses or conditions which, according to the judgment of the investigator, may result in physical harm caused by the study, or which may impair study compliance