The purpose of this study is to evaluate the safety and one year disease-free survival of total or subtotal colectomy and proctocolectomy in stage IIIc and stage IV epithelial ovarian, fallopian tube, and primary peritoneal cancer (EOC, FTC, PPC).

This trial is to assess the perioperative complications, hospitalization expenses and days, and one year disease-free survival of patients who underwent total or subtotal colectomy as part of the surgical procedures for ovarian cancer, versus partial intestinal resection in the therapy for ovarian cancer.

Inclusion Criteria:

• Age ≥18 years and ≤ 75 years.
• Epithelial ovarian cancer, fallopian tube cancer, primary peritoneal carcinoma with pathology confirmed International Federation of Gynecology and Obstetrics (FIGO) stage IIIc or IV
• Extensive colonic metastasis, tumor involving the major part of bowel surface and/or mesentery
• Optimal cytoreductive surgery, including hysterectomy, bilateral salpinges-oophorectomy, omentectomy, and resection of all metastatic lesions, with a residual disease no more than 0.5cm
• Eastern Cooperative Oncology Group (ECOG) performance status 0-2.
• American Society of Anesthesiologists (ASA) performance 1-2.
• Follow-up available.
• Written informed consent.

Exclusion Criteria:

• Low-malignant potential ovarian tumor.
• Patient who underwent enterostomy in the surgery procedure.
• Tumor involving small intestine alone.
• More than 2 anastomoses.
• Other condition that could interfere with provision of informed consent, compliance to study procedures, or follow-up.
• Prior invasive malignancies within the last 5 years showing activity of disease.