William J. Gradishar, MD

Presence of disseminated tumor cells may be a reason to consider additional adjuvant therapy.

The presence of disseminated tumor cells (DTCs) in the bone marrow is a prognostic factor for patients with early-stage breast cancer who have no other evidence of clinically apparent distant metastatic disease. However, not all individuals with early-stage breast cancer and DTCs in the bone marrow will develop a relapse. Fundamental questions include whether the number of DTCs, if present, change with adjuvant therapy, what the clinical importance of persistent DTCs is, and whether anything meaningful can be done therapeutically to improve outcome if DTCs persist post–adjuvant therapy.

To address these questions, Norwegian investigators conducted a prospective, multicenter, nonrandomized study involving 1121 patients (age, 18–70 years) with early-stage breast cancer (axillary node-positive or pT1c-T4, axillary node-negative disease) and no detectable metastasis. Patients had completed primary surgery and six cycles of chemotherapy with fluorouracil, epirubicin, and cyclophosphamide. Adjuvant endocrine and anti-HER2 therapy was allowed. A first bone-marrow aspiration was performed 2 to 3 months after chemotherapy (BM1) to determine DTC status, and a second aspiration was performed 6 months later (BM2). If DTCs were present at BM2, the patient received docetaxel.

At BM2, 7.2% of patients were DTC-positive. Among 72 who received docetaxel, 20.8% had persistent DTCs as well as a shorter disease-free interval than patients with no DTCs after treatment (46.7% relapsed). Docetaxel-treated patients with no remaining DTCs had a similar disease-free interval (8.8% relapsed) as those with no DTCs at BM1 and BM2 (12.7% relapsed).

Citation(s):

Naume B et al. Clinical outcome with correlation to disseminated tumor cell (DTC) status after DTC-guided secondary adjuvant treatment with docetaxel in early breast cancer. J Clin Oncol 2014 Nov 3; [e-pub ahead of print].