RATIONALE: Drugs used in chemotherapy, such as carboplatin, paclitaxel, and cisplatin, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Radiation therapy uses high-energy x-rays and other types of radiation to kill tumor cells. Giving chemotherapy and radiation therapy after surgery may kill any tumor cells that remain after surgery. It is not yet known whether carboplatin and paclitaxel are more effective with or without cisplatin and radiation therapy in treating patients with endometrial cancer.

PURPOSE: This randomized phase III trial is studying carboplatin and paclitaxel to see how well they work when given with or without cisplatin and radiation therapy in treating patients with stage I, stage II, stage III, or stage IVA endometrial cancer.