Circulating tumor cells in small-cell lung cancer: a predictive and prognostic factor.
BACKGROUND
Initial response of small-cell lung cancer (SCLC) to chemotherapy is high, and recurrences occur frequently, leading to early death. This study investigated the prognostic value of circulating tumor cells (CTCs) in patients with SCLC and whether changes in CTCs can predict response to chemotherapy. Patients and methods In this multicenter prospective study, blood samples for CTC analysis were obtained from 59 patients with SCLC before, after one cycle, and at the end of chemotherapy. CTCs were measured using CellSearch systems.


RESULTS
At baseline, lower numbers of CTCs were observed for 21 patients with limited SCLC (median = 6, range 0-220) compared with 38 patients with extensive stage (median = 63, range 0-14,040). Lack of measurable CTCs (27% of patients) was associated with prolonged survival (HR 3.4; P ≤ 0.001). CTCs decreased after one cycle of chemotherapy; this decrease was not associated with tumor response after four cycles of chemotherapy. CTC count after the first cycle of chemotherapy was the strongest predictor for overall survival (HR 5.7; 95% CI 1.7-18.9; P = 0.004).


CONCLUSIONS
Absolute CTCs after one cycle of chemotherapy in patients with SCLC is the strongest predictor for response on chemotherapy and survival. Patients with low initial CTC numbers lived longer than those with higher CTCs.
Departments of Pulmonary Diseases. Electronic address: t.j.n.hiltermann@umcg.nl.
T J N
TJN
Hiltermann
Departments of Medical Oncology.
M M
MM
Pore
Departments of Pathology and Medical Biology.
A
A
van den Berg
Departments of Pathology and Medical Biology.
W
W
Timens
Departments of Medical Epidemiology, University of Groningen, University Medical Center Groningen, Groningen.
H M
HM
Boezen
Department of Pulmonary Diseases, Scheper Hospital, Emmen.
J J W
JJW
Liesker
Department of Pulmonary Diseases, Medisch Spectrum Twente, Enschede.
J H
JH
Schouwink
Department of Pulmonary Diseases, Deventer Hospital, Deventer, The Netherlands.
W J A
WJA
Wijnands
Departments of Pulmonary Diseases.
G S M A
GSMA
Kerner
Departments of Medical Oncology.
F A E
FAE
Kruyt
Immunicon Corporation, Huntingdon Valley, Veridex LCC, Raritan, USA.
H
H
Tissing
Immunicon Corporation, Huntingdon Valley, Veridex LCC, Raritan, USA.
A G J
AGJ
Tibbe
Faculty of Science and Technology, University of Twente, Enschede, The Netherlands.
L W M M
LWMM
Terstappen
Departments of Pulmonary Diseases.
H J M
HJM
Groen
D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use; D014408:Biomarkers, Tumor; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology* / Q000532:radiotherapy; D008297:Male; D008875:Middle Aged; D009360:Neoplastic Cells, Circulating; D017671:Platinum Compounds / Q000627:therapeutic use; D011379:Prognosis; D011446:Prospective Studies; D055752:Small Cell Lung Carcinoma / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology* / Q000532:radiotherapy; D016896:Treatment Outcome
D000970:Antineoplastic Agents; D014408:Biomarkers, Tumor; D017671:Platinum Compounds