This phase III trial studies how well letrozole with or without paclitaxel and carboplatin works in treating patients with stage II-IV low-grade serous carcinoma of the ovary or peritoneum. Letrozole is an enzyme inhibitor that lowers the amount of estrogen made by the body which in turn may stop the growth of tumor cells that need estrogen to grow. Drugs used in chemotherapy, such as paclitaxel and carboplatin, work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. It is not yet known whether giving letrozole alone or in combination with paclitaxel and carboplatin works better in treating patients with low-grade serous carcinoma of the ovary or peritoneum compared to paclitaxel and carboplatin without letrozole.

This trial tests how well darolutamide in combination with leuprolide acetate and exemestane works in treating patients with ovarian granulosa cell tumors that have come back after a period of improvement (recurrent). The combination of darolutamide, leuprolide acetate, and exemestane may be an effective approach to shrinking or stabilizing recurrent ovarian granulosa cell tumors or preventing them from coming back.