gms | German Medical Science

Background: Disseminated tumor cells (DTC) in the bone marrow (BM) of breast cancer patients are an independent prognostic factor for both survival and disease free survival. Information about how well disseminated and potentially dormant tumor cells are targeted by adjuvant systemic therapy is limited. We looked at the fate of occult tumor cells detected in the BM at primary surgery and after the effect of different adjuvant systemic therapy regimens.

Patients and Methods: BM aspirates taken at the time of primary surgery and after a median interval of 12 months after completion of adjuvant systemic treatment in a group of 112 patients were examined. Immunocytochemistry using the A45BB3 monoclonal antibody for pancytokeratin and APAAP detection was used to determine the presence of DTC. 27 patients completed an adjuvant chemotherapeutic treatment regimen, 34 patients received hormone therapy only, while 51 patients were treated with a combination of both.

Results: Out of a total of 373 patients that underwent BM aspiration at primary surgery, 112 completed participation in our study. Out of these 112 patients, 93 had DTC in their BM. The positivity rate under adjuvant therapy for this group dropped from 83% to 24% at the time of the second sampling. To evaluate the association between tumor cell persistence and clinicopathological factors, patients were subdivided in two groups according to their bone marrow status during follow-up. Tumor cell persistence was only associated with high tumor grading (p=0.020) but did not correlate with other established risk factors, such as tumor-size (p=0.055), lymph node status (p=0.48) or the type of adjuvant therapy (p=0.447).

Conclusion: Adjuvant treatment regimens are not effective to completely eliminate cytokeratin positive cells. Their persistance could offer a rationale for the exploration and establishment of secondary adjuvant treatment regimens.