293P - Quantification of tumor-specific DNA in blood of healthy women and breast cancer patients

Date 01 October 2012
Event ESMO Congress 2012
Session Poster presentation III
Topics Breast Cancer, Early Stage
Translational Research
Presenter Svetlana Tamkovich
Authors S.N. Tamkovich1, V.A. Myleiko2, A.V. Starikov3, V.I. Permyakova4, V.V. Vlassov2, P. Laktionov2
  • 1Cellular Biology Group, Institute of Chemical Biology and Fundamental Medicine, 630090 - Novosibirsk/RU
  • 2Cellular Biology Group, Institute of Chemical Biology and Fundamental Medicine, 630090 - Novisibirsk/RU
  • 3Mammology Department, National Novosibirsk Regional Oncologic Dispensary, 630090 - Novisibirsk/RU
  • 4Hematology Department, Central Clinical Hospital, 630090 - Novisibirsk/RU

Abstract

Despite of tumor location DNA from cancer cells was shown to got in circulating blood, thus DNA circulating in blood represent the valuable source of diagnostic material for non-invasive blood based tests for cancer.

Material and methods

Blood from healthy female (n = 50) and breast cancer patients (n = 23, T1-2, N0-1, M0) were fractionated into plasma and cellular fractions, cell-surface-bound cirDNA (csbDNA) were eluted from cell surface with PBS/EDTA and trypsin solutions [1]. Total DNA was quantified with TaqMan PCR for LINE-1 repeats [2], methylated DNA of RAR�2 gene promoter was quantified with methylation-specific SYBR Green Real Time PCR [3].

Results

Breast cancer patients had significantly higher mean concentration of methylated RAR�2 gene promoter in circulating DNA (cirDNA) and csbDNA fractions as compared to healthy controls: 192 vs. 132 pg/ml and 619 ng/ml vs. 413 pg/ml, respectively; P < 0.005. No correlation was found between cirDNA levels and stage of tumor. ROC-curve analysis demonstrated sensitivity and specificity of cirDNA-based breast cancer detection as 52% and 65% respectively for cut-off value of 0.61 for plasma tumor cirDNA and 70% and 61% respectively for cut-off value of 0.75 when cirDNA and csbDNA were analysed simultaneously. The data obtained demonstrate that along with cirDNA csbDNA provides a valuable source of material for breast cancer diagnostics.

1. Clin. Chem., 2005. V. 51. P. 1317-1319.

2. Anal. Biochem., 2011. V. 408. P. 354-356.

3. Eur. J. Cancer Prev., 2011. V. 20. P. 453-455.

Disclosure

All authors have declared no conflicts of interest.