Oophorectomy Followed by Chemotherapy Versus Chemotherapy Alone in Colorectal Cancer Patients

Inclusion Criteria: 1. age ≥ 18 2. histologically confirmed adenocarcinoma of colon 3. documented ovarian metastasis in CT or MRI or PET-CT 4. advanced (stage IV), metastatic, or recurrent 5. ECOG performance status of 0\~2 6. adequate marrow, hepatic, renal and cardiac functions 7. no prior surgical treatment to ovary 8. provision of a signed written informed consent Exclusion Criteria: 1. patient who refuses oophorectomy 2. medical condition in which surgery cannot be tolerated Any waiver of these inclusion and exclusion criteria must be approved by the investigator on a case-by case basis prior to enrolling the subject. This must be documented by the investigator. No subject will be allowed to enroll in this study more than once.