Background: Disseminated tumor cells (DTCs) in the bone marrow from breast cancer patients have been reported as a prognostic factor. We evaluated prognostic value of DTCs in non-metastatic breast cancer according to ER/PR and HER2 status.

Methods: Bone marrow aspirates were obtained from 607 non-metastatic breast cancer patients at the time of primary surgery between 1999 and 2012. DTCs were identified via immunomagnetic enrichment followed by flow cytometry (IE/FC) using anti-EpCAM monoclonal antibody (mAb). The relation between high DTC count and clinical outcome was analyzed with ER/PR and HER2 status. Patients whose DTC count is in the above 80th percentile were considered as higher DTCs.

Results: Median and mean DTC count were 7.2 and 24.5 cells/mL and 80th percentile was 18.5 cells/mL. Higher DTC group (> = 18.5 cells/mL) showed impaired disease free survival (DFS; P = .019, log-rank) after median follow-up of 59 months. This poorer outcome in higher DTC group was observed mainly in ER(-) patients and triple negative patients with lower DFS (P = .002 and 018) and overall survival (OS; P = .004 and .012). There was no significant survival difference in ER(+), HER2(+), or ER(+)/HER2(-) patients.

Conclusion: High DTCs in non-metastatic breast cancer is associated with poor clinical outcome, especially in ER(-) or triple negative patients. However, DTCs is not related with prognosis in other ER/HER2 status groups.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr PD6-8.