Use of disseminated tumor cells to predict outcome in patients with stage I-III breast cancer.

Abstract

119 Background: Published studies from Europe have shown the presence of disseminated tumor cells (DTCs) to independently predict outcomes in patients with non-metastatic breast cancer. The purpose of this study was to assess the experience with DTCs at a tertiary cancer center and to see if these cells indeed predict outcomes in patients with stage I-III breast cancer. Methods: Clinical stage I-III breast cancer patients seen at a single tertiary cancer center provided consent to participate in an IRB-approved study involving collection of bone marrow (5 ml x 2 tubes) at the time of surgery for their primary breast cancer. DTCs were assessed by anti-CK antibody cocktail (AE1/AE3, CAM5.2, MNF 116, CK 8 and 18) following cytospin. A positive result was defined as the presence of one or more cells per 5 ml of bone marrow. Statistical analyses used chi-square and Fischer’s exact tests. Results: Three hundred and sixty-six patients were prospectively enrolled. Mean age was 53 years. Median follow-up was 32 months. DTCs were identified in 109 patients (30%). Ten percent of patients with DTCs (11/109) and 3% of patients without DTCs (8/257) died (p = 0.009). Overall survival (OS) in patients with DTCs was 30 months vs. 31 months in those without DTCs. DTCs did not predict relapse free survival (P=NS). On multivariate analysis the presence of DTCs was an independent predictor of worse overall survival (p < 0.0001). No correlation was observed between the presence of DTCs and lymph node metastases and/or other clinicopathologic variables. Conclusions: The presence of DTCs was an independent predictor of worse OS in patients with stage I-III breast cancer. Consideration should be given to the utilization of DTCs as predictors of outcome in clinical practice.