AUTHOR=Huang Chao H. , Wick Jo A. , Sittampalam Gurusingham Sitta , Nirmalanandhan Victor Sanjit , Ganti Apar Kishor , Neupane Prakash C. , Williamson Stephen K. , Godwin Andrew K. , Schmitt Sarah , Smart Nora J. , Spencer Sarah , Van Veldhuizen Peter J. 

TITLE=A Multicenter Pilot Study Examining the Role of Circulating Tumor Cells as a Blood-Based Tumor Marker in Patients with Extensive Small-Cell Lung Cancer

JOURNAL=Frontiers in Oncology

VOLUME=Volume 4 - 2014

YEAR=2014

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2014.00271

DOI=10.3389/fonc.2014.00271

ISSN=2234-943X

ABSTRACT=Abstract 


Background: SCLC, a variant of lung cancer marked by early metastases, accounts for 13% of all lung cancers diagnosed in US. Despite high response rates to treatment, it is an aggressive disease with a median survival of 9-11 months for patients with EX-SCLC.  Detection of CTCs is a novel laboratory technique currently in use to determine response to therapy and to predict prognosis in breast, colorectal and prostate cancer.  We initiated a study to study the role of CTC as a biomarker of response and relapse in patients with EX-SCLC. 

Methods: We collected blood sample from chemotherapy naïve patients with EX-SCLC prior to initiation of therapy, after completion of systemic therapy, and follow up every 6-8 weeks and at relapse. The CTC was determined using the Cell Search system in a central laboratory.  The study was conducted in 4 different sites and it was reviewed and approved by respective Research Review Committee and IRBs.  

Results: We enrolled 27 patients with EX-SCLC, 1 was excluded due ineligibility, all patients were treated with platinum and etoposide. We observed partial response in 16 patients, stable disease in 3 patients, 1 with progression of disease and not assessed in 7 patients (5 deceased, 2 not available). The overall median number of CTCs in 24 patients measured at baseline and post-tx was 75 (range 0 to 3430) and 2 (range 0 to 526), respectively. A significant reduction in CTCs from baseline to post-treatment was identified—for the 15 subjects, the median reduction was 97.4% (range -100% to +100%, p < 0.001). Higher baseline CTC and percentage change in post treatment CTC were associated with decreased survival. 
Conclusions: We were able to demonstrate feasibility of using CTCs as a biomarker of response and prognosis in patients with EX-SCLC in clinical setting. CTC could be a useful biomarker in the management of EX-SCLC to predict response to therapy and predict outcome.