A phase II study of paclitaxel for the treatment of ovarian stromal tumors: An NRG Oncology/ Gynecologic Oncology Group Study

Objective To estimate the probability of complete clinical response and toxicity of paclitaxel as second-line chemotherapy in measurable disease patients with malignant tumors of the ovarian stroma, and to evaluate the value of inhibin for predicting response. Methods Thirty-one patients with histologically confirmed ovarian stromal tumor were enrolled from 2000 to 2013. Patients were required to have measurable recurrent disease, and to have received only one prior chemotherapy regimen. Paclitaxel 175 mg/m² was administered over a 3 hour infusion, cycling every 21 days. Inhibin levels were drawn within two weeks of initiation of treatment. Results Of 31 women enrolled, there was only one complete response (3.2%), and partial response in eight of 31 cases (25.8%). The pretreatment inhibin level for the single patient who had complete response was 88 pg/mL. Median progression-free survival was 10.0 months and overall survival was 73.6 months. Myelosuppression was common with 12 of 31 patients (38.7%) suffering grade 3 or 4 neutropenia, leukopenia, or anemia. Conclusion There were too few complete responses to warrant continued evaluation of paclitaxel as a single agent treatment for women with recurrent malignant ovarian stromal tumors with measurable disease according to the primary objective of the study. Toxicity of the regimen was acceptable. Pretreatment inhibin is not a reliable tumor marker as it was not elevated in the majority of patients.