The Utility of Circulating Tumor Cells in Monitoring Patients with Recurrent Ovarian Cancer
DW Kindelberger, U Matulonis. Brigham and Women's Hospital, Boston, MA; Dana-Farber Cancer Institute, Boston, MA
Background: Introduction: Epithelial ovarian cancer is diagnosed in approximately 22,000 women every year in the United States. Over 16,000 deaths per year occur, making this cancer the most lethal gynecologic malignancy. The number of circulating tumor cells in the peripheral blood before treatment is an independent predictor of survival in patients with metastatic breast cancer, prostate cancer, and colorectal cancer. In patients with ovarian cancer, the prognostic significance of circulating tumor cells is unclear, and investigators report conflicting results. We examined the utility of immumagnetically isolated circulating tumor cells (CTCs), captured using the CellSearch System by Veridex, in predicting response to treatment in patients with recurrent ovarian cancer.
Design: Fifty consecutive patients with known recurrent ovarian cancer were selected as part of an IRB-approved study at the Dana Farber Cancer Institute. Circulating tumor cells were isolated according to standard protocols for the Veridex CellSearch System. Briefly, 7.5 ml of blood was collected in Cell Save Vacutainer tubes. Blood samples were processed within 36 hours of collection by dilution with buffer, followed by a low-speed (800xg) centrifugation in a Beckman table-top centrifuge. Samples were then immediately processed with the CellTracks Autoprep instrument using the Epithelial Cell Kit. Following processing, tumor cells were enumerated using the CellTracks Analyzer. Clinical data, including CA-125 levels, type of chemotherapy regimen, and clinical course were correlated with the number of CTCs.
Results: The average number of CTCs obtained using the CellSearch system was quite low (2 CTCs/sample). The number of CTCs failed to correlate with CA-125 levels, type or duration of chemotherapy, or clinical course.
Conclusions: In patients with recurrent ovarian cancers (predominantly high grade serous adenocarcinoma) the recovery of CTCs using the CellSearch system is very poor, possibly due to the low rates of hematogenous spread for these tumors. As a consequence of thses low numbers of recovered cells, the absolute CTC counts do not show any correlation with CA-125 levels, type or duration of chemotherapy, or disease progression. Unlike the scenario seen with some other epithelial tumor types, (breast, prostate, colorectal cancers), the number of CTCs determined by the Veridex CellSearch System does not seem to be clinically a useful marker for patients with recurrent ovarian cancers.
Category: Gynecologic & Obstetrics
Wednesday, March 24, 2010 1:00 PM
Poster Session VI # 167, Wednesday Afternoon