Clinical relevance of circulating tumor cells in ovarian, fallopian tube and peritoneal cancer.

Abstract

e17080 Background: Presence of circulating tumor cells (CTCs) in peripheral blood is associated with impaired clinical outcome in a variety of cancers. So far, limited data are available on the significance of CTCs in gynaecological malignancies. Aims of the present study were to evaluate the dynamics of CTCs in patients with ovarian, fallopian tube and peritoneal cancer during chemotherapy and to assess the clinical relevance of these changes. Methods: 38 patients with ovarian (n=31), fallopian tube (n=4) and peritoneal (n=3) cancer were included into the study. All patients received chemotherapy in the first-line setting (n=19) or tumor recurrence (n=19). CTC analysis was performed prior to systemic treatment, after three and six cycles of chemotherapy and analysed using CellSearch system (Veridex). A tumor cell was defined as EpCAM+, cytokeratin+, CD45-, and positive for the nuclear stain DAPI. CTC positivity was defined as detection of at least one CTC per 7.5 ml blood. Results: 11 out of 38 (29%) patients were CTC positive at baseline. Positivity rate was 20% in patients with first-line setting and 37% in those with tumor recurrence. 1of the 4 patients with fallopian tube cancer presented with CTCs in contrast to 1 out of 3 patients with peritoneal cancer and 10 out of 31 ovarian cancer patients. Presence of CTCs was not correlated with other prognostic factors, such as the FIGO stage, nodal status, or grading. CTC positivity declined to 8% after three cycles of cytotoxic therapy and no patient was CTC positive after 6 cycles of chemotherapy. 12 patients died during follow-up. Patients with CTCs at baseline had significantly shorter overall survival compared with CTC negative patients (p = 0.002; mean OS 5.8 [95%-CI 2.7-8.9] vs. 15.2 [10.5-19.8] months, median OS 3.0 [1.4-4.6] vs. not reached). In the subgroup of patients with primary cancer, CTC positivity was significantly associated with overall survival in the univariate analysis (p = 0.008). Conclusions: Hematogenous dissemination of single tumor cells is a common phenomenon in ovarian, fallopian tube and peritoneal cancer. Patients with CTCs in the peripheral blood at time of diagnosis are more likely to die than those who are CTC-negative at baseline.