SAN ANTONIOThe question of how much weight to give isolated bone marrow
micrometastases in making breast cancer treatment decisions was the focus of
three presentations at the 26th San Antonio Breast Cancer Symposium. Two of
these studies confirmed that occult micrometastases are a warning sign of poor
prognosis in many breast cancer patients. The third found that isolated tumor
cells in the sentinel lymph node are not a major problem in patients with
ductal carcinoma in situ (DCIS).
Stephan Braun, MD, reported on behalf of European researchers in the
Collaborative Group on Bone Marrow Mi-crometastasis that occult metastatic
cells in the bone marrow are associated with worse overall survival for breast
cancer patients as a whole and particularly for node-negative patients who have
not received adjuvant therapy (abstract 7). He suggested that patients who test
positive for occult metastatic cells may be candidates for more aggressive
treatment strategies and that adjuvant therapy might not be needed in some
patients who do not have such cells in their bone marrow.
Dr. Braun, of the University Clinic for Obstetrics and Gynecology,
Innsbruck, Austria, reported a pooled analysis of 10-year survival for 4,268
breast cancer patients from eight recently published studies addressing
long-term outcome of patients with and without occult metastatic cells.
Patients received chemotherapy that was standard at the time of the study, but
Dr. Braun pointed out that the study covered quite a long time, over which
The primary study endpoint was overall survival. Patients were free of
distant metastases at primary surgery, 90% were stage T1/T2; 58% were node
negative; 70% had received adjuvant therapy. Occult metastatic cells were
detected in the bone marrow of 1,259 patients (30%). The proportion of patients
with occult cells increased significantly (P < .001) across strata of
tumor size, nodal status, and grading.
The pooled analysis showed significantly shorter disease-free survival in
patients with occult metastatic cells (hazard ratio [HR] 2.10, P <
.001). Multivariate analysis that included bone marrow positivity, lymph node
positivity, tumor size, tumor grade, and estrogen-receptor (ER) positivity
supported the importance of occult metastatic cells and showed a significant
decrease in overall survival in patients positive for occult cells (HR 2.28,
P < .001).
Dr. Braun said that the presence of occult metastatic cells is an
independent predictive factor of survival for patients with stage I-III breast
The analysis included 10 years of follow-up with median follow-up of 58
months, during which 763 patients (18%) died. Death from any cause was
significantly more likely in occult-cell-positive patients (HR 2.33, P <