Annual Meeting Proceedings Part 1 - American Society of Clinical ...

1056 General Poster Session (Board #21G), Sat, 8:00 AM-12:00 PM
The role and significance of FoxM1 in invasive breast cancer. Presenting
Author: Cha Kyong Yom, Department of Surgery, Seoul National University
Bundang Hospital, Seoul National University College of Medicine, Seongnam,
South Korea
Background: The Forkhead Box protein M1 (FoxM1) is known to regulate a
variety of biologic processes in mammalian cells including cell growth and
survival, angiogenesis, DNA damage response, chemotherapeutic drug
resistance, and cancer cell migration and invasion. We evaluate the role
and significance of Fox M1 in primary breast cancer in vitro and analyzed
the relation with FoxM1 expression and clinicopathologic features. Methods:
Immunohistochemical staining was used for evaluation of cytoplasmic
expression of FoxM1 with TMA of invasive breast cancer. In various breast
cancer cell lines, we evaluated FoxM1 expression and treated docetaxel/
cisplatin in combination with Siomycin A (FoxM1 inhibitor) for BT20 cell
line. Results: From Nov 1995 to Jul 2007, in 84 patients with stage 1-3
invasive breast cancer, FoxM1 expression was noted in 58.7%. Median
follow-up duration was 85.1 months. Lymphovascular invasion was positively
correlated with FoxM1 expression (p�0.040). In multivariate analysis,
FoxM1 expression (p�0.005), HR negativity (p�0.002), high histologic
grade (p�0.023), hign nuclear grade (p�0.045), lymphovascular invasiveness
(p�0.017), and stage 3 cancer (p�0.015) matched poor disease-free
survival. In vitro study, FoxM1 was expressed BT474, JIMT-1, BT20,
HCC-1937, and MDA-MB-231 cell lines. The inhibition of FoxM1 had
synergistic effect on cisplatin treatment, not docetaxel in BT20 cell.
Conclusions: FoxM1 expression was noted in triple negative breast cancer
cell lines and its inhibition had synergistically cytotoxic effect on BT20 cell
line in combination with cisplatin. Although the further in vivo and clinical
study should be needed to draw the solid conclusions, FoxM1 could be both
a promising target of treatment for triple negative breast cancer and a
independent prognostic factor.
1058 General Poster Session (Board #22A), Sat, 8:00 AM-12:00 PM
Next-generation sequencing mutational analysis of triple-negative breast
cancer patients from matched FFPE and fresh frozen samples. Presenting
Author: Mark Landers, AltheaDx, San Diego, CA
Background: TNBC is an aggressive subtype of breast cancer accounting for
10-15% of all cases. TNBC tumors (ER-/PR-/HER-) are more common in
patients with BRCA mutations. BRCA mutations leading to homologous
DNA repair deficient tumors enhance the efficacy of chemotherapy and
PARP inhibitors. BRCA mutations have been identified in 20% of patients
without family history. Identification of germline and somatic BRCA
mutations in unselected patients could increase the number of patients
who benefit from these therapies. Determining BRCA mutational status
from FFPE and fresh frozen specimens may enable clinical studies in these
patient populations.We describe the development of an NGS BRCA
mutational assay compatible with FFPE and fresh frozen samples using
tumor/adjacent normal matched tissues. Methods: Matched samples were
purchased from Cureline. gDNA was isolated by lysis/column purification
(Qiagen) and enriched for BRCA exons/flanking regions (Halogenomics
Selector). Fragment libraries were constructed (Ion Torrent frag express)
and prepared for sequencing by emPCR (Ion Torrent Template Xpress).
Libraries were sequenced for 65 cycles (Ion Torrent PGM) yielding 2-4M
reads/sample. Variants were called from tMAP aligned reads by GATK and
VarScan. Overlapped exonic variants were filtered by p-value (�0.0001)
from VarScan. Results: In the first patient set normalized average depth of
BRCA exon coverage was 64X and 72X per 150K reads in FFPE and fresh
frozen tissues respectively covering 95-100% of target. hg19 alignment
rates varied between 97-99% across all samples. Similar numbers of
variants were called in both FFPE (12) vs. fresh frozen (13) with a
corresponding mean duplicate removed depth of coverage of 23.3X and
42.4X at the called positions. 10/13 calls in fresh frozen overlapped with
those in FFPE. A tumor specific somatic frameshift insertion in BRCA2 was
detected in both FFPE and fresh frozen tissues. Conclusions: Results
indicate that NGS mediated BRCA mutational analysis demonstrates
equivalent utility in both FFPE and fresh frozen tumor samples although
more sequencing reads are required to produce equivalent depth of
coverage starting from FFPE samples.
Breast Cancer—Triple-Negative/Cytotoxics/Local Therapy
63s
1057 General Poster Session (Board #21H), Sat, 8:00 AM-12:00 PM
Use of gene expression and alternative splicing signatures to discriminate
breast cancer stem cells from fibroblasts. Presenting Author: David T.
Weaver, Verastem Inc, Cambridge, MA
Background: Tumors frequently contain cancer stem cells (CSCs) or
tumor-initiating subpopulations, with an ability to self-renew and regenerate
all cell types within the tumor. Basal-like breast cancers exhibit
features of CSCs, including expression of surface markers, even though
these cells are rare. Given the role of CSCs in the recurrence and spread of
cancer, there is an urgent need to develop new therapeutic agents that
target CSCs. Development of CSC-targeted drugs will be greatly facilitated
by biomarkers that can identify CSCs to aid in patient selection and
determination of drug response. Defining the CSCs in tumors is complicated
by the high mesenchymal nature of fibroblasts. Analysis of gene
expression and alternative splicing patterns in CSCs that are not observed
in fibroblasts may provide valuable new CSC-specific markers. Methods:
Alternative splicing and gene expression microarray strategies were used to
identify selected exons and differentially expressed genes between 10
Basal human breast cancer cell lines and a combination of 12 Luminal and
3 fibroblast cell lines. Q-PCR analysis was conducted to determine
candidate CSC gene differential expression between Basal, Luminal, and
Fibroblast cells lines. Results: Expression levels of 11 genes were higher
and 24 genes were lower in the Basal cell lines versus Luminal or
fibroblastic cell lines. Comparison of Basal cell lines to the Luminal/
Fibroblast cell lines identified 36 cassette exons that were included, and
26 that were excluded in Basal cell lines. Also, 19 genes were upregulated
in Basal cell lines compared to the other groups as detected by Q-PCR.
Interestingly, the 19-multigene model defined the Triple Negative Breast
Cancer patients that were Likely to Recur under standard chemotherapy
with a p � 1.90e-03 and AUC 0.723. Conclusions: Gene and exon marker
sets distinguish CSC versus fibroblasts and may be instructive in identifying
patients that recur early in Triple Negative Breast Cancer. The CSCassociated
RNA signatures identified here will be further refined to develop
new CSC-specific diagnostic markers to stratify breast cancer patients and
monitor response to novel CSC-targeted therapies.
1059 General Poster Session (Board #22B), Sat, 8:00 AM-12:00 PM
A randomized phase II trial of doxorubicin plus pemetrexed followed by
docetaxel versus doxorubicin plus cyclophosphamide followed by docetaxel
as neoadjuvant chemotherapy (NACT) for early breast cancer: Three-year
follow-up data. Presenting Author: Andreas Schneeweiss, University Hospital
Heidelberg, Heidelberg, Germany
Background: NACT for early breast cancer allows in vivo chemosensitivity
testing. Primary results of this randomized, non-comparative 2-arm study
have been published (Schneeweiss et al, Ann Oncol 2011). Here we
provide 3-year follow-up data for disease-free survival (DFS) and safety.
Methods: 257 patients (pts) with untreated operable T2–T4a–c N0–2 M0
breast cancer were randomly assigned to receive either four cycles of
doxorubicin 60 mg/m² plus pemetrexed 500 mg/m² every 3 weeks (q3w)
followed by four cycles of docetaxel 100 mg/m² q3w (AP-D; 135 pts), or
four cycles of doxorubicin 60 mg/m² plus cyclophosphamide 600 mg/m²
q3w followed by four cycles of docetaxel 100 mg/m² q3w (AC-D; 122 pts).
Both arms were stratified according to hormone receptor (HR) status
(estrogen and/or progesterone receptor positive vs both negative) and study
center. Surgery was carried out within 2 months after last chemotherapy.
Primary objective was pathological complete response (pCR) rate in the
breast (ypT0/is). Secondary objectives included long-term efficacy and
safety measures. DFS and adverse event data were collected from all
patients for 3 years or until progression or death. The Kaplan-Meier (KM)
analysis technique and Cox regression method were used as statistical
measures. KM analyses were performed on HR-positive and -negative pts
subgroups. Results: As reported earlier, pCR rates were 16.5% for AP-D and
20.2% for AC-D. The 3-year DFS rate was 76% and 77% for AP-D and
AC-D, respectively. Cox regression analysis for the overall enrolled population
(regardless of treatment) revealed significantly longer DFS in HRpositive
than in HR-negative pts (hazard ratio 0.35; 95% CI 0.22–0.58; p
� 0.001). In HR-positive pts, the 3-year DFS rate was 88% (95% CI:
81–95%) with AP-D and 83% (95% CI: 74–91%) with AC-D. In HRnegative
pts, the 3-year DFS rate was 55% (95% CI: 40–70%) for AP-D
and 68% (95% CI: 53–82%) for AC-D. The 3-year follow-up data did not
reveal any changes in the safety profile compared to the previously
published results. Conclusions: The 3-year DFS rates of both NACTs are in
line with published studies.
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