Prognostic relevance of disseminated tumor cells in the bone marrow of patients with primary breast cancer--results of a standardized follow-up.

BACKGROUND: The prognostic significance of disseminated tumor cells from bone marrow (BM-DTCs) of breast cancer patients has been demonstrated previously. In this study, data of a standardized long term follow-up of 829 patients with examination of BM-DTCs at primary diagnosis are presented. PATIENTS AND METHODS: BM aspiration and immunocytochemical examination of DTCs was performed according to a standardized protocol. Follow-up data of all patients were adjusted with the cancer registries of southern Bavaria.
RESULTS: A total of 268 patients (32%) had BM-DTCs with a median of 2 (1-1223)/2 x 10⁶ cells. Positive BM findings correlated with tumor size (p=0.032), but not with other histopathological parameters. After a median follow-up of 73 months, BM-DTCs were highly relevant for the development of distant metastases (p=0.006) and, beneath standard histological parameters, reduced overall survival (p=0.038).
CONCLUSION: These results confirm the prognostic relevance of the detection of BM-DTCs. Newer methods, such as detection of circulating tumor cells in blood, will have to demonstrate comparable prognostic information in the future.