PRIMARY OBJECTIVE:~I. To examine if letrozole monotherapy/maintenance (L/L) is non-inferior to intravenous (IV) paclitaxel/carboplatin and maintenance letrozole (CT/L) with respect to progression-free survival (PFS) in women with stage II-IV primary low-grade serous carcinoma of the ovary or peritoneum after primary surgical cytoreduction.~SECONDARY OBJECTIVES:~I. To compare the nature, frequency and maximum degree of toxicity as assessed by Common Terminology Criteria for Adverse Events (CTCAE) version (v) 5.0 for each treatment arm.~II. To compare the relative frequency of objective tumor response in those with measurable disease after cytoreductive surgery for each treatment arm.~III. To compare overall survival for each treatment arm. IV. To compare the CT/L and L/L arms with respect to patients' adherence to letrozole therapy as measured by pill counts.~OUTLINE: Patients are randomized to 1 of 2 arms.~ARM I: Patients receive paclitaxel IV over 3 hours and carboplatin IV on day 1. Cycles repeat every 21 days for up to 6 cycles. Patients then receive letrozole orally (PO) once daily (QD) in the absence of disease progression or unacceptable toxicity.~ARM II: Patients receive letrozole PO QD in the absence of disease progression or unacceptable toxicity.~After completion of study treatment, patients are followed up every 3 months for 2 years, every 6 months for 3 years, then annually thereafter.
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, fallopian tube, 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, fallopian tube, or peritoneum compared to paclitaxel and carboplatin without letrozole.