The significance of circulating epithelial cells in Breast Cancer patients by a novel negative selection method.
OBJECTIVE
A negative selection method for the enumeration and characterization of circulating epithelial/cancer cells (CCC) in Breast Cancer (BC) patients is described. This manual procedure yields reproducible results of high sensitivity and selectivity suitable for research laboratories.


METHODS
We conducted a prospective blood sampling study in 105 women with stage 1-4 BC attending clinics at the University of Maryland Greenebaum Cancer Center to define the prevalence of CCC utilizing our sensitive double gradient centrifugation and magnetic cell sorting CCC detection and enumeration method. CCC were isolated and enumerated from 15 to 20 ml of venous blood drawn before the start of systemic therapy and periodically thereafter for up to 24 months. One or more CCC/sample was considered a positive result.


RESULTS
We analyzed 487 samples for the presence of CCC; the median number of samples/patient was 4 (range 1-8). CCC were detected in 56% of patients, 19%-stage 1; 43%-stage 2; 46%-stage 3; 83%-stage 4. The probability of being positive for the presence of CCC is significantly associated with the stage of cancer (P < 0.0001). The frequency of CCC positive patients and samples increased with the advancing stage of disease. Presence of more than 10 CCC/sample was associated with the decreased survival and increased probability of having metastatic disease P = 0.001.


CONCLUSIONS
Increasing number of CCC/sample correlates with the adverse outcome and poorer survival (P < 0.0001). Our CCC test based on the negative selection procedure may provide valuable prognostic information.
University of Maryland Marlene and Stewart Greenebaum Cancer Center, Baltimore, MD 21201, USA. ktkaczuk@umm.edu
Katherine H Rak
KH
Tkaczuk
Olga
O
Goloubeva
Nancy S
NS
Tait
Faye
F
Feldman
Ming
M
Tan
Zhao-Ping
ZP
Lum
Stephen A
SA
Lesko
David A
DA
Van Echo
Paul O P
PO
Ts'o
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000401:mortality / Q000473:pathology*; D004847:Epithelial Cells / Q000473:pathology*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008875:Middle Aged; D009367:Neoplasm Staging; D009360:Neoplastic Cells, Circulating / Q000473:pathology; D011446:Prospective Studies