Detection of isolated tumor cells in BM from breast-cancer patients: significance of anterior and posterior iliac crest aspirations and the number of mononuclear cells analyzed.
BACKGROUND
The aim of this study was to determine the influence and significance of different aspiration sites and the number of mononuclear cells (MNC) analyzed on the frequency of isolated tumor cell (ITC) detection by immunocytochemistry (ICC) in BM aspirates from breast-cancer patients.


METHODS
BM aspirates were collected from the two anterior and two posterior crests just prior to primary surgery. The BM was processed separately from the anterior and the posterior crests, and cytospins (2 x 10(6) MNC) were prepared for ICC examination. The remaining cells were pooled, followed by cytospin preparation and ICC analysis (2 x 10(6) MNC/test). In addition, a fraction of the pooled cells were further processed by negative immunomagnetic selection, for enrichment of ITC. Out of 100 patients selected, 97 were further analyzed.


RESULTS
The ICC examination from the separate crests revealed 37 positive BMs from the anterior iliac crest and 30 positive from the posterior crest. Twenty-one of the samples were positive at both sides. Five patients had 10 or more ITCs detected. In these, an unequal distribution of ITCs between the sides was observed, but in favor of neither. ICC analysis of 2, 4 and 6 x 10(6) MNC revealed respectively 22, 46 and 52 positive BMs out of the 97 analyzed. These results were correlated to the clinical outcome after a median 43 months follow-up. Thirteen of the patients underwent systemic relapse. Analyzing 2 x 10(6) MNC by ICC, 27.3% of the BM+ patients developed systemic disease, compared with 9.3% of the BM+ patients (P = 0.0056, log rank test). Analyzing 6 x 10(6) MNC reduced the correlation between ITC in BM and clinical outcome.


CONCLUSIONS
No significant difference in the detection rate of ITCs from the anterior and the posterior iliac crests was found, although the distribution of ITCs did show a great variability. Analyzing a higher number of BM cells increased the number of positive BM specimens detected. However, this increased detection rate reduces the prediction by ICC of early systemic relapse.
Department of Surgery Ullevål University Hospital Oslo, Oslo, Norway.
G
G
Wiedswang
E
E
Borgen
R
R
Karesen
B
B
Naume
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001854:Bone Marrow Cells / Q000166:cytology* / Q000473:pathology; D001943:Breast Neoplasms / Q000175:diagnosis / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D011379:Prognosis