Flow cytometric assessment of monocyte activation markers and circulating endothelial cells in patients with localized or metastatic breast cancer.
BACKGROUND
Monocyte activation in cancer patients may be reflective of anticancer activity. However, studies indicate that recruitment of macrophages can actually promote tumor growth and angiogenesis. Assessment of other microenvironmental cells such as circulating endothelial cells (CECs) may provide additional information regarding disease progression. The objective of this study was to assess monocyte activation and CECs in breast cancer patients and determine the potential clinical relevance during disease progression.


METHODS
Patients (n = 41) with localized or metastatic breast cancer who were not currently receiving treatment were eligible for study inclusion. Peripheral blood was collected and analyzed by flow cytometry for monocyte activation (Leuko64 assay kit), and for CECs (CD146(+)CD45(-) phenotype).


RESULTS
Metastatic breast cancer patients demonstrated a higher monocyte CD64 index relative to normal donors and localized breast cancer patients (P < 0.05). Furthermore, breast cancer patients had a lower monocyte CD163 index relative to normal donors (P = 0.008). Localized breast cancer patients demonstrated higher levels of CD146(+)CD45(-) cells CECs relative to metastatic breast cancer patients and normal donors. Within the localized breast cancer population, levels of CD146(+)CD45(-) cells increased with disease stage (P < 0.05).


CONCLUSIONS
These results suggest that monocyte activation and CECs may play a role in breast cancer progression. We speculate that monocyte activation may reflect a reaction to metastatic cells and/or response to tissue damage caused by metastatic growth in distant organs. Furthermore, the observation that CECs increase with disease stage in localized breast cancer suggests that CECs could be a useful surrogate marker for disease progression in this patient population.
Goodale
David
D
London Regional Cancer Centre, London Health Sciences Centre, Ontario, Canada.
Phay
Carolina
C
Brown
Wendy
W
Gray-Statchuk
Leslie
L
Furlong
Patricia
P
Lock
Michael
M
Chin-Yee
Ian
I
Keeney
Michael
M
Allan
Alison L
AL
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000032:analysis / Q000097:blood; D014408:Biomarkers, Tumor / Q000032:analysis / Q000097:blood; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000276:immunology / Q000556:secondary; D002277:Carcinoma / Q000175:diagnosis* / Q000276:immunology / Q000556:secondary; D049109:Cell Proliferation; D002634:Chemotaxis, Leukocyte / Q000276:immunology; D042783:Endothelial Cells / Q000276:immunology / Q000473:pathology*; D005260:Female; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D016130:Immunophenotyping / Q000379:methods; D008875:Middle Aged; D009000:Monocytes / Q000276:immunology / Q000473:pathology*; D009362:Neoplasm Metastasis / Q000175:diagnosis / Q000276:immunology; D011237:Predictive Value of Tests
D015415:Biomarkers; D014408:Biomarkers, Tumor