Neoadjuvant chemotherapy for low-grade serous carcinoma of the ovary

Abstract

5571 Background: Neoadjuvant chemotherapy (NACT) has been associated with significant tumor reduction prior to interval debulking surgery, enabling optimal cytoreduction in up to 50% of patients with high-grade ovarian carcinomas deemed initially unresectable. Since low-grade serous carcinoma (LGSC) appears to be relatively less chemosensitive, we sought to evaluate the outcomes of women with ovarian LGSC treated with platinum-based NACT. Methods: Using institutional databases, we identified 18 women with low-grade serous carcinomas of the ovary who were treated with neoadjuvant platinum-based chemotherapy between 1978 and 2003. Patient demographic and clinical variables were abstracted from the medical records. Progression-free survival (PFS) and overall survival (OS) were estimated using the method of Kaplan-Meier. Results: The median age at diagnosis was 44 years (range, 21 to 81 years). NACT was given for extensive or non-resectable disease in 16 patients (89%) and for unknown reasons in 2 patients (11%). Ten patients (42%) underwent exploratory laparotomy with biopsy only prior to beginning chemotherapy. A median of 6 cycles of chemotherapy was given (range, 2 to 16) and included the following regimens: platinum/taxane (n=12 patients); platinum/cyclophosphamide (n=3 patients); and platinum/leuprolide acetate (n=3 patients). Of the 13 patients who had CA-125 levels available, 8 (62%) had a ≥50% reduction between pre- and post-NACT levels. However, response, determined by radiographic survey at completion of NACT, demonstrated one patient (6%) with a complete response, no patients (0%) with a partial response, and 16 patients (89%) with stable disease. One patient (6%) was not evaluable. Fifteen patients (83%) underwent interval cytoreductive surgery, which was optimal in 8 cases (53%), suboptimal in 4 cases (27%) and unknown in 3 cases (20%). Median PFS and OS for all patients were 18.6 and 56.1 months, respectively. Conclusions: A low response rate to platinum-based NACT was observed among women with LGSC of the ovary. These findings suggest that LGSC is not as responsive to conventional chemotherapy as high-grade serous carcinoma. Prospective clinical trials, focusing specifically on LGSC, are needed to make meaningful advances for this group of patients. No significant financial relationships to disclose.