Annals of Oncology

abstracts
Legal entity responsible for the study: Hellenic Cooperative Oncology Group,
INRASTES-National Centre for Scientific Research "Demokritos"
Funding: Hellenic Cooperative Oncology Group, INRASTES-National Centre for
Scientific Research "Demokritos"
Disclosure: F. Fostira: Advisory Board - Astra Zeneca. All other authors have declared
no conflicts of interest.
106P
Identification of breast cancer associated altered DNA
methylation in peripheral blood using MALDI-TOF mass
spectrometry
R. Yang 1 , B. Burwinkel 2
1 MammaScreen Group, University Hospital of Heidelberg, Heidelberg, Germany,
2 Molecular Biology, University Hospital Heidelberg, Heidelberg, Germany
Background: Breast cancer (BC) is the leading cause of cancer-related mortality in
women worldwide. Changes in DNA methylation in peripheral blood could be
associated with malignancy at early stage. However, the BC-associated DNA
methylation signatures in peripheral blood were largely unknown.
Methods: Illumina 27K Methylation Array and Illumina 450K Methylation Array for
the discovery of BC-related aberrant methylation sites in peripheral blood. The top
hints were selected and validated using the MALDI-TOF Mass Spectrometry
(MassARRAY, Agena Bioscience, Inc.) in two independent case-control studies with
subjects from different centers. Gene expression levels were measured by real-time PCR
and correlated with methylation. The clustering of samples by multiple CpG sites from
a total of eight genes was realized by logistic regression. Receiver operating
characteristic curve analyses was used to determine the discriminatory power.
Results: The methylation of an eight-gene-panel in peripheral blood cells was
significantly correlated with BC, and showed outstanding discriminatory power for
distinguishing BC cases from non-cancer controls (first validation round with 270
familial BC case and 251 non-cancer controls: AUC = 0.94, 95% C.I. 0.92-0.96; second
validation round with 189 sporadic BC case and 189 non-cancer controls: AUC = 0.93,
95% C.I. 0.91-0.96). This panel also shows robust power for the breast cancer at early
stage (in the second validation round 101 stage 0&I sporadic BC case vs. 189
non-cancer controls: AUC = 0.93, 95% C.I. 0.90-0.96). In addition, these blood-based
DNA methylation signatures were similar among BC patients with differential clinical
characteristics regardless of stage, receptor status and menopause status. The
expression of four genes were also analysed in the leucocytes from 72 subjects and
showed inversely correlation with the methylation levels (p < 0.05).
Conclusions: This study reveals a strong association between decreased methylation of
genes in peripheral blood and BC, and provides a promising blood-based marker panel
for the detection of early BC.
Legal entity responsible for the study: University Hospital of Heidelberg
Funding: This work was supported by the Dietmar-Hopp Foundation, University
Hospital of Heidelberg, Helmholtz Society and the German Cancer Research Center
(DKFZ). The familial BC samples were collected within a project funded by the
Deutsche Krebshilfe (Grant number: 107054).
Disclosure: R. Yang, B. Burwinkel: Inventors of a provisional patent application
relating to the subject matter of this manuscript and therefore declare a potential
conflict of interests.
107P
Evaluation of RAD50 as a prognostic marker of survival in
breast cancer patients
K.V. Havrysh 1 , V.V. Filonenko 1 , I.G. Serebriiskii 2 , R.G. Kiyamova 3
1 Cell Signalling, Institute of Molecular Biology and Genetics of National Academy of
Sciences of Ukraine, Kyiv, Ukraine, 2 Molecular Therapeutics, Fox Chase Cancer
Center, Philadelphia, PA, USA, 3 Institute of Fundamental Medicine and Biology,
Kazan Federal University, Kazan, Russian Federation
Background: Breast cancer (BC) is common and aggressive malignancy. Resistance to
drugs often develops and is not fully understood. One of the possible reasons of this is
increased activity of the DNA repair system in cancer cells. Since molecular disruption
of RAD50, which implicated in DNA double-break repair, sensitizes breast tumor cells
to cisplatin-based chemotherapy in cell culture, one may be hypothesized that level of
RAD50 gene expression in breast tumors could be considered as a potential predictive
and prognostic marker of BC. The aim of this investigation was to examine the impact
of RAD50 gene features (level of expression and Copy Number Alteration (CNA)) on
survival of BC patients taking into account their clinical characteristics: stage of disease
and molecular subtype of tumors.
Methods: Data on the clinical behavior, RAD50 gene expression (RNA-Seq (V2)) and
CNA (deletion, gain, amplification) of the BC patients were obtained from three
independent studies (TCGA, Provisional (n = 1105); TCGA, Cell 2015 (n = 1105);
TCGA, Nature 2012(n = 825) using the cBioPortal (www.cbioportal.org/). Cases with
absence of necessary data were excluded, leading to data sets from 2359 to 1220
samples. Testing intergroup differences (ANOVA, Tukey’s HSD, Wilcoxon tests and
Spearman’s correlation) and analysis of BC patients’ survival (Kaplan-Meier and
Log-rank test) were performed using RStudio.
Results: A pairwise comparison groups of BC patients showed that level of RAD50
gene expression fluctuates significantly in breast tumors of various molecular subtypes
(except pair of Luminal A and B), between patients on 1 st and 2 nd stages of disease and
patients with different CNA. The patients with high level of RAD50 gene expression
had significantly reduced overall survival in comparison with the patients that had low
level of RAD50 gene expression only among patients with CNA. Correlation analysis of
CNA and level of RAD50 gene expression has shown that high level of RAD50 gene
expression bonded with gain and amplification of RAD50 gene.
Conclusions: Our finding allows us to consider the gain and amplification of RAD50
gene as traits which are associated with poor survival of BC patients and RAD50 as
potential prognostic marker of BC.
Legal entity responsible for the study: Kiyamova Ramziya Gallyamovna
Funding: Russian Science Foundation (project 15–15–20032)
Disclosure: All authors have declared no conflicts of interest.
108P
HER2 based expression subpopulations in TNBC: pathological
aspects and clinical significance
S.M. Ilie 1 , C. Desauw 2 , M. Hebbar 3
1 Medical Oncology, University of Medicine and Pharmacy "Carol Davila",
Bucharest, Romania, 2 Medical Oncology, C.H.U. Claude Huriez, Lille, France,
3 Oncologie médicale, C.H.U. Claude Huriez, Lille, France
Background: Triple negative breast cancer (TNBC) is defined as hormone receptors
less than 1% and human epithelial growth factor receptor 2 (HER2) negative by
immunofluorescence. HER2 negative tumors can express an intracellular domain and
present a HER2 positive phenotype. Before Trastuzumab era, the prognostic was worse
in HER2 over expressed early breast cancer than in triple negative counterpart.
Methods: We conducted a retrospective analysis in order to explore the clinical
significance of different degrees of tumor HER2 immunohistochemistry expression: 0,
1 or 2 inside triple breast cancer population.
Results: We analysed data from 440 early stage breast cancer patients, primary treated
by surgery, addressed to the Department of Medical Oncology of University Hospital
of Lille France, for adjuvant chemotherapy, between January 2010 and April 2013. 47
patients (10, 6%) had triple negative phenotype, 67pts (15,2%) HER2 positive, 326 pts
(74, 1%) luminal. The mean age was 47 years, 19 %( 9pts) and deleterious BRCA1 or
BRCA2 mutations were found in 10 pts (21%). The patients were more likely to have
stage IIA 48 %( 23pts), invasive ductal carcinoma 74 %( 35pts), the surgery was
conservatory in 28 pts(59,5pts)and the majority, 44pts (93%) was anthracycline
exposed. The distribution of HER2 score among TN patients were as follows: 62%
(29pts) negative, 27,6 %( 13pts) one plus, 10,4 %( 5pts) two plus and negative for in
situ hybridization. HER 2 positivity correlated with pT (p = 0, 05), Ki67 (p = 0, 06) and
tumor grade (p = 0, 08). Pathologic stage pT, Ki67, and HER2 score were associated
with relapse (p < 0, 05). For a median follow up of 38 months (range 24 to 52mo), 8pts
(17%) experienced recurrence: loco regional in three cases and distant metastasis in
5pts (10%). The median event free survival (EFS) was 29, 8 months (range 7 to 76 mo)
and the median PFS of 11,3months. Median EFS was shorter in HER2+ score (29,8mo)
respectively in HER2 positive (29,2mo) population than in triple negative HER2
negative (31,8mo), without reaching the significance (P = 0, 9).
Conclusions: The proportion of HER2 positivity inside TNBC population is valuable.
The HER2 score 2 correlates with prognostic negative tumor features and associates
with poor outcome in our analysis.
Legal entity responsible for the study: University Hospital of Lille France
Funding: University Hospital of Lille France
Disclosure: All authors have declared no conflicts of interest.
109P
Annals of Oncology
Genetic influence of EGFR-PI3K-mTOR pathway and other loci
in triple-negative breast cancer
C. Cabrera 1 , M.J. Arranz 2 , M.L. Surralles Calnge 3 , A. Salas 3 , X. Tarroch 3 ,
L. Ibañez 2 , A. Garcia 4 , S. Gonzalez Jimenez 1 , M. Campayo 1 , L. Cirera 1
1 Oncology and Hematology Department, Hospital Univeristari Mutua Terrassa,
Terrassa, Spain, 2 Fundacio Docència i Recerca Mútua Terrassa, Hospital
Univeristari Mutua Terrassa, Terrassa, Spain, 3 Pathology Department, Hospital
Univeristari Mutua Terrassa, Terrassa, Spain, 4 Gynecology and Obstretics
Department, Hospital Univeristari Mutua Terrassa, Terrassa, Spain
Background: Breast cancer (BC) is the most frequent cancer in women. About 15% of all
cases account for the most aggressive subtype: triple negative breast cancer (TNBC). TNBC
biological heterogeneity has been explained in both gene expression profile studies and
genome wide association studies (GWAS). Our study explores the role of single nucleotide
polymorphisms (SNP) in TNBC. We hypothesized that new loci can confer risk and
prognosis of TNBC, given its well-known tendency to genetic aberrations.
Methods: In this retrospective study, we genotyped a group of SNP in 111
paraffin-embedded tumor samples of patients diagnosed with TNBC (cases) and in 176
blood samples of healthy donors (controls). The SNP were selected from 5 genes
(MAP3K1, PI3K, TERT, EGFR, and mTOR) known for their implication in TNBC and
other types of cancer.
Results: Univariate analysis with chi-square test comparing genotypic frequencies
between cases and controls confirmed statistical significance in EGFR rs4947986 (p=
0.001) and TERT rs2736100 (p=