Monoclonal Antibody Therapy in Treating Patients With Ovarian Cancer or Primary Peritoneal Cancer in Remission Following Surgery and Chemotherapy

RATIONALE: Monoclonal antibodies can locate tumor cells and either kill them or deliver tumor-killing substances to them without harming normal cells. It is not yet known whether monoclonal antibody therapy is more effective than observation for ovarian cancer or primary peritoneal cancer that is in remission. PURPOSE: Randomized phase III trial to compare the effectiveness of monoclonal antibody therapy with that of observation in treating patients who have ovarian cancer or primary peritoneal cancer in remission following surgery and chemotherapy.