Circulating Tumor Cells as Potential Biomarkers in Bladder Cancer.
OBJECTIVE
We explored the diagnostic use of circulating tumor cells in patients with neoadjuvant bladder cancer using enumeration and next generation sequencing.


METHODS
A total of 20 patients with bladder cancer who were eligible for cisplatin based neoadjuvant chemotherapy were enrolled in an institutional review board approved study. Subjects underwent blood draws at baseline and after 1 cycle of chemotherapy. A total of 11 patients with metastatic bladder cancer and 13 healthy donors were analyzed for comparison. Samples were enriched for circulating tumor cells using the novel IsoFlux™ System microfluidic collection device. Circulating tumor cell counts were analyzed for repeatability and compared with Food and Drug Administration cleared circulating tumor cells. Circulating tumor cells were also analyzed for mutational status using next generation sequencing.


RESULTS
Median circulating tumor cell counts were 13 at baseline and 5 at followup in the neoadjuvant group, 29 in the metastatic group and 2 in the healthy group. The concordance of circulating tumor cell levels, defined as low-fewer than 10, medium-11 to 30 and high-greater than 30, across replicate tubes was 100% in 15 preparations. In matched samples the IsoFlux test showed 10 or more circulating tumor cells in 4 of 9 samples (44%) while CellSearch® showed 0 of 9 (0%). At cystectomy 4 months after baseline all 3 patients (100%) with medium/high circulating tumor cell levels at baseline and followup had unfavorable pathological stage disease (T1-T4 or N+). Next generation sequencing analysis showed somatic variant detection in 4 of 8 patients using a targeted cancer panel. All 8 cases (100%) had a medium/high circulating tumor cell level with a circulating tumor cell fraction of greater than 5% purity.


CONCLUSIONS
This study demonstrates a potential role for circulating tumor cell assays in the management of bladder cancer. The IsoFlux method of circulating tumor cell detection shows increased sensitivity compared with CellSearch. A next generation sequencing assay is presented with sufficient sensitivity to detect genomic alterations in circulating tumor cells.
Division of Hematology and Oncology, Comprehensive Cancer Center, University of Michigan, Ann Arbor, Michigan. Electronic address: ajjai@med.umich.edu.
Ajjai
A
Alva
Division of Hematology and Medical Oncology, Helen Diller Family Comprehensive Cancer Center, University of California-San Francisco, San Francisco, California.
Terence
T
Friedlander
Division of Hematology and Oncology, Comprehensive Cancer Center, University of Michigan, Ann Arbor, Michigan.
Melanie
M
Clark
Division of Hematology and Oncology, Comprehensive Cancer Center, University of Michigan, Ann Arbor, Michigan.
Tamara
T
Huebner
Division of Hematology and Oncology, Comprehensive Cancer Center, University of Michigan, Ann Arbor, Michigan.
Stephanie
S
Daignault
Division of Hematology and Oncology, Comprehensive Cancer Center, University of Michigan, Ann Arbor, Michigan.
Maha
M
Hussain
Department of Urology, University of Michigan, Ann Arbor, Michigan.
Cheryl
C
Lee
Department of Urology, University of Michigan, Ann Arbor, Michigan.
Khaled
K
Hafez
Department of Urology, University of Michigan, Ann Arbor, Michigan.
Brent
B
Hollenbeck
Department of Urology, University of Michigan, Ann Arbor, Michigan.
Alon
A
Weizer
Department of Urology, Helen Diller Family Comprehensive Cancer Center, University of California-San Francisco, San Francisco, California.
Gayatri
G
Premasekharan
Fluxion Biosciences, San Francisco, California.
Tony
T
Tran
Fluxion Biosciences, San Francisco, California.
Christine
C
Fu
Fluxion Biosciences, San Francisco, California.
Cristian
C
Ionescu-Zanetti
Fluxion Biosciences, San Francisco, California.
Michael
M
Schwartz
Fluxion Biosciences, San Francisco, California.
Andrea
A
Fan
Department of Urology, Helen Diller Family Comprehensive Cancer Center, University of California-San Francisco, San Francisco, California.
Pamela
P
Paris
D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009360:Neoplastic Cells, Circulating; D010865:Pilot Projects; D011446:Prospective Studies; D001749:Urinary Bladder Neoplasms / Q000097:blood* / Q000473:pathology* / Q000628:therapy
circulating; genomics; molecular; neoadjuvant therapy; neoplastic cells; pathology; urinary bladder neoplasms