Page 205 - Read Online

Galletti et al. Using CTCs in prostate cancer

Table 2: CTC-based molecular markers investigated in prostate cancer
Enrichment
strategy Biomarker Assay Patient cohort Main findings References
Ficoll ERG RT-PCR 72 pts treated with taxane Detection of TMPRSS2-ERG was [81]
chemotherapy (50 with significantly correlated with shorter
docetaxel and 22 with PSA-progression free survival
cabazitaxel)
FACS sorting AR IF 20 pts (10 abi-treated, 10 Increase in median AR staining intensity [59]
abi-naïve) in patients with prior abi exposure
Ki-67 IF 16 pts for AR expression Increased AR expression and nuclear [59]
and 10 pts for AR nuclear localization associated with elevated Ki-
localization 67
Steroidogenic RT-PCR 5 pts Detection of AKR1C3, SRD5A1, [82]
enzymes CYP17A1 in CTCs from pts with CRPC
ScreenCell ® EMT-related RT-PCR 308 CTCs from 8 pts Subset of EMT-related genes found [86]
genes in CTCs of CRPC; less frequently in
castration-sensitive PC
HD-CTC assay AR IF 27 pts (12 with NEPC, Low or absent AR expression, lower [87]
(EPIC Sciences™) 5 with atypical clinical cytokeratin expression, and smaller
features suggestive of morphology in CTCs from NEPC pts
NEPC, 10 with CRPC)
ARv7 IF 191 samples from 161 pts Nuclear expression of ARv7 in CTCs [69]
associated with superior survival on
taxane therapy over AR inhibitors
CellSearch ® AR IF Taxane treated pts: 17 13/18 (72%) of progression samples [62]
samples from responding/ showed CTCs with nuclear AR; 12/17
stable pts; 18 samples at (71%) of responding/stable samples
progression showed CTCs with cytoplasmic AR
IF 8 pts (baseline and at 5/8 (63%) patients showed increase [60]
progression after abi or median AR expression at progression
enza)
FISH 9 pts with > 5 CTCs Marked AR amplification in 5/9 (56%) [88]
pts (all with CTC > 50)
FISH 33 pts with > 4 CTCs 28/33 (85%) pts had CTCs with < 3 [76]
copies of AR, 10/33 (30%) with < 4-5
copies, 15/33 (45%) with > 5 copies
ERG FISH 49 pts with > 4 CTCs ERG rearrangement in 23/49 (47%) pts [76]
(matched ERG gene status of tumor
tissue in all cases)
PTEN FISH 49 pts with > 4 CTCs PTEN loss in 13/49 (27%) pts; (6/13 [76]
(46%) pts had homozygous loss of
PTEN in all CTCs)
EGFR IF 20 pts with > 5 CTCs 18/20 (90%) pts with EGFR positive [88]
CTCs
AdnaTest ARv7 RT-PCR 62 pts (31 treated with abi, 0/18 (0%) pts with detectable levels of [42]
31 treated with enza) ARv7 had PSA response to either abi or
enza
RT-PCR 37 pts receiving taxane No difference in PSA response between [68]
chemotherapy pts with or without detectable ARv7
MagSweeper Prostate-specific RT-PCR 20 CTCs from 4 pts 19/20 (95%) of CTCs positive for at [35]
markers least one prostate marker (AR, PSA,
KLK3, TMPRSS2)
EpCAM-conjugated ERG RT-PCR 41 pts with CTCs TMPRSS2-ERG fusion detected in [76]
magnetic beads 15/41 (37%) of pts
VERSA AR IF 17 pts (4 treatment-naïve, Pts responding to AR-targeted or [47]
10 responding to therapy, chemotherapy treatments showed lower
3 progressing on therapy) nuclear AR percentage compared to pts
progressing
ARv7 RT-PCR 26 pts (19 treated with AR ARv7 was detected in 5/7 (71%) pts [47]
targeted therapies) who had evidence of radiographic
progression compared to 1/19 (5%)
pts without evidence of radiographic
progression
Continued...
Journal of Cancer Metastasis and Treatment ¦ Volume 3 ¦ September 27, 2017 197