Monitoring tumour cells in the peripheral blood of small cell lung cancer patients.
BACKGROUND
Flow cytometry was used to enumerate tumour cells in longitudinal studies of peripheral blood from small cell lung cancer (SCLC) patients, together with magnetic bead selection to isolate and identify these cells. As part of a trial, 11 patients received either standard (four weekly) chemotherapy with ifosfamide, carboplatin, and etoposide (ICE) or accelerated (two weekly) ICE with filgrastim (granulocyte colony-stimulating factor [G-CSF]) and autologous stem cell support.


METHODS
Fresh venous blood was taken throughout treatment and follow-up. Aliquots were stained with a "tumour-specific" antibody against epithelial tissue (Ber EP4), verified as a good marker of SCLC cells by immunohistochemistry. Matched samples labelled with Ber EP4 were separated magnetically by adding a secondary bead-antibody conjugate for confirmation of tumour cell identity.


RESULTS
Circulating tumour cells were detected and monitored throughout treatment periods. An initial rise in circulating cells after the first cycle was followed by a fall in both treatment arms to baseline levels set by normal controls. This was achieved by week 12 in the accelerated treatment arm and by week 24 in the standard arm.


CONCLUSIONS
Flow cytometry and magnetic bead isolation can be used to identify changes in numbers of circulating tumour cells in patients undergoing chemotherapy for SCLC and thereafter during follow-up periods. Absence of tumour cells may indicate a more favourable patient group who would benefit from a more intense course of treatment.
Kularatne
B Y
BY
Division of Genomic Medicine, Section of Oncology and Cellular Pathology, Institute for Cancer Studies, University Medical School, Sheffield S10 2RX, United Kingdom.
Lorigan
P
P
Browne
S
S
Suvarna
S K
SK
Smith
M O
MO
Lawry
J
J
D000915:Antibody Affinity; D018288:Carcinoma, Small Cell / Q000097:blood* / Q000188:drug therapy / Q000473:pathology; D002452:Cell Count / Q000379:methods; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D018189:Immunomagnetic Separation / Q000379:methods; D008137:Longitudinal Studies; D008168:Lung / Q000166:cytology; D008175:Lung Neoplasms / Q000097:blood* / Q000188:drug therapy / Q000473:pathology; D015166:Monitoring, Immunologic / Q000379:methods; D016896:Treatment Outcome