Abstract 98P
Aim/Background
Functional inactivation of BRCA1 gene increase the risk of developing breast cancer. Germline mutation of BRCA1 is responsible for Hereditary Breast and Ovarian Cancer. BRCA1 promoter methylation has been proposed as an alternative mechanism to inactivate BRCA1 in sporadic breast cancer. Most of cases with BRCA1 mutations are triple negative breast cancer (TNBC) but, the association between each subtypes of breast cancer and BRCA1 methylation is not clear. Thus, we investigated the BRCA1 methylation status and protein expression of BRCA1 in each subtypes of breast cancer.
Methods
121 samples, which contained 82 frozen and 39 acetone embedded samples, were obtained from breast cancer patients undergoing surgery with informed consents. Using methylation-specific PCR analysis which was validated based on cell line survey, methylation levels were calculated as a percentage of the reference. Setting a cut-off value of 10%, positive methylation was determined. The association between BRCA methylation and clinicopatholgical factors was analyzed by Chi-square test.
Results
The number of each subtypes is 43 in hormone receptor (HR) + , HER2-, 21 in HR + , HER2-, 19 in HR-, HER2 + , 38 in TNBC. Positive methylation was detected only in triple negative breast cancer (9/38, 24%) which is statistically significant compared with HR + , HER2- (0/43, p < 0.0.1), HR + , HER2 + (0/21, p < 0.05), and HR-, HER2- (0/19, p < 0.05). In cases with BRCA methylation, six out of eight cancer (75%) showed absence of BRCA protein. Frequency of low expression of BRCA protein by subtypes is; TNBCs (12/31, 39%), HR + , HER2- (2/41, 4.9%), HR + , HER2- (0/21, 0%), HR-, HER2+ (1/10, 10%) (p < 0.01).
Conclusions
Our data suggest hypermethylation of BRCA1 is highly related with TNBC subtype, which decrease BRCA protein expression. PARP inhibitors might be used as therapeutic targets for these population.
Clinical trial identification
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
Who is a cancer survivor? a study into the lay understanding of cancer identity using a crowdsourced population
Presenter: Sze Yan Cheung
Session: Poster presentation 2
Resources:
Abstract
What is the evidence that hospital inpatient palliative consultation teams improve adult cancer patient outcomes, a systematic review
Presenter: Shawn Lin
Session: Poster presentation 2
Resources:
Abstract
Vitamin D deficiency in Hong Kong advanced cancer patients: result of first 50 patients
Presenter: Kam Wing Woo
Session: Poster presentation 2
Resources:
Abstract
Visual outcomes and ocular coherence tomography in patients with intraocular retinoblastoma with eye preservation
Presenter: Atul Batra
Session: Poster presentation 2
Resources:
Abstract
Venous thromboembolism in hospitalized cancer patients receiving chemotherapy in a Japanese community hospital: A prospective observational study
Presenter: Hiromitsu Kitayama
Session: Poster presentation 2
Resources:
Abstract
Validation of âCancer Dyspnoea Scaleâ for advanced cancer patients in a tertiary cancer centre
Presenter: Anuja Damani
Session: Poster presentation 2
Resources:
Abstract
Utilization pattern of anti-emetics in prevention of chemotherapy induced nausea and vomiting - study from a developing country
Presenter: Chikkaemmiganur Avinash
Session: Poster presentation 2
Resources:
Abstract
Using Quality Improvement Methods and Time-Driven Activity Based Costing to Improve Value-Based Cancer Care Delivery at a Cancer Genetics Clinic
Presenter: Ryan Tan
Session: Poster presentation 2
Resources:
Abstract
Unique fund raising program for poor paediatric cancer patients: a little effort from a school level
Presenter: Anwesha Mukherjee
Session: Poster presentation 2
Resources:
Abstract
Underreporting of transfusion reaction in Indonesian cancer patients
Presenter: Audric Albertus
Session: Poster presentation 2
Resources:
Abstract