Disseminated tumor cells of breast cancer patients: a strong prognostic factor for distant and local relapse.
OBJECTIVE
Clinical significance of disseminated tumor cells (DTC) in bone marrow of early breast cancer patients has been reported, but improvements in detection methods are needed.


METHODS
Bone marrow aspirates from 621 patients with stage I to III breast cancer were screened for cytokeratin-positive (CK+) cells. CK+ cells were categorized into DTC only if they had specific morphologic features of tumor cells. Bone marrow status and clinical and pathologic variables of the patients were correlated with clinical outcome after a median follow-up of 56 months.


RESULTS
DTC and non-DTC CK+ cells were detected in 15% and 34% of patients, respectively, with no correlation with clinical and pathologic variables. On univariate analysis, DTC detection was associated with a poorer distant metastasis-free survival (DMFS; P = 0.0013) and overall survival (OS; P = 0.005). Moreover, DTC detection was also associated with local relapse-free survival (P = 0.0009). On multivariate analysis, DTC detection was an independent prognostic factor for DMFS, local relapse-free survival, and OS. There was no significant interaction between DTC detection and hormonal receptors status (P = 0.34). Non-DTC CK+ cells had no clinical significance.


CONCLUSIONS
DTC detection is a powerful prognostic marker for DMFS and OS in early breast cancer patients and can be individualized from irrelevant non-DTC CK+ cells by morphologic criteria. Biologically, despite high rates of systemic adjuvant therapy and locoregional irradiation in this series, DTC detection remains a prognostic factor of distant and, more strikingly, of local relapse, in favor of resistance to treatment of locally or distant disseminated cancer cells in DTC-positive patients.
Department of Medical Oncology, Institut Curie, Paris, France.
Francois-Clément
FC
Bidard
Anne
A
Vincent-Salomon
Stéphanie
S
Gomme
Claude
C
Nos
Yann
Y
de Rycke
Jean Paul
JP
Thiery
Brigitte
B
Sigal-Zafrani
Laurent
L
Mignot
Xavier
X
Sastre-Garau
Jean-Yves
JY
Pierga
D000328:Adult; D000368:Aged; D001853:Bone Marrow / Q000473:pathology*; D001943:Breast Neoplasms / Q000401:mortality / Q000473:pathology*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007633:Keratins / Q000378:metabolism; D008875:Middle Aged; D009362:Neoplasm Metastasis / Q000473:pathology*; D009364:Neoplasm Recurrence, Local / Q000473:pathology*; D009360:Neoplastic Cells, Circulating / Q000473:pathology*; D011379:Prognosis
D007633:Keratins