Abstract 59P
Background
BC is a heterogeneous disease with variable clinical outcomes among patients with the same clinical and pathological characteristics, treated with similar treatment. Despite significant improvement in the outcomes, many of them acquire resistance to multiple anticancer drugs, leading to recurrence and /or metastasis. It remains an unmet need to identify robust molecular defects and novel biomarkers to adopt individualized treatment decisions in BC. CGP using next generation sequencing (NGS) provides more druggable gene aberrations at “one go” that includes somatic BRCA (sBRCA), homologous recombinant repair pathway alteration (HRR) and tumor agnostic markers like tumor mutation burden (TMB) and microsatellite instability (MSI) burden.
Methods
140 BC cases at HCG cancer centre were profiled using Illumina TruSight Oncology 500 assay on a NextSeq2000 in an IRB-approved study. The findings from NGS data were discussed in the molecular tumor board (MTB) and recommendations were documented for change in clinical management and follow-up.
Results
Clinically relevant variants were detected in 133/140 BC patients (95%) with actionable mutations in >80% cases with direct impact on therapy and constituted of 47% Tier 1 and 41% Tier 2 mutations. CGP revealed a multitude of genomic alterations such as PI3KCA/AKT/PTEN signalling pathway (32%) in HR+Her2- mBC and ESR1 mutation (7%) in HR+ mBC predictive of resistance to anti-Her2 and endocrine therapy respectively. 22 patients (16%) with sBRCA and HRR pathways alteration treated either with platinum / PARP inhibitors post platinum treatment were found to have partial-to-complete pathological response (pCR). 23 BC patients with high TMB (16%) were initiated on immunotherapy as a single drug or in combination with chemotherapy and are on follow up. The mutation spectrum, HRR pathway alterations and high TMB of triple- negative BC (TNBC) cases revealed a distinctive mutational profile with clinical utility in >95% cases.
Conclusions
Recommending CGP tests at a more appropriate time helps in modifying BC treatment protocol, clinical decisions and provides patients with greater benefit from targeted treatments based on their specific gene alterations and resistance mechanism.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
B.S. Ajaikumar: Financial Interests, Personal and Institutional, Member of Board of Directors, Executive Chairman: HCG. All other authors have declared no conflicts of interest.
Resources from the same session
39P - Prognostic significance of hypoxic microenvironment biomarkers in invasive ductal breast cancer
Presenter: Sungmin Kang
Session: Poster Display
Resources:
Abstract
40P - Intra-tumoral CD3, CD4, and CD8 as prognostic biomarkers in Asian breast cancer
Presenter: Jia Wern Pan
Session: Poster Display
Resources:
Abstract
41P - Brown fat activation demonstrated on FDG PET/CT predicts survival outcome
Presenter: Sonya Park
Session: Poster Display
Resources:
Abstract
42P - A promising anticancer drug for triple-negative breast cancer: OZ-001 suppresses tumor growth by dual targeting STAT3 and calcium signaling
Presenter: Jisun Kim
Session: Poster Display
Resources:
Abstract
43P - Performance evaluation of a combined risk model for breast cancer risk prediction in Indonesian population (TRIP Study)
Presenter: Marco Wijaya
Session: Poster Display
Resources:
Abstract
44P - Pathological complete response to neoadjuvant chemotherapy and outcomes in Her-2 negative locally advanced breast cancer
Presenter: Amrith Patel
Session: Poster Display
Resources:
Abstract
45P - Demographic determinants of pathological complete response after neoadjuvant chemotherapy in breast cancer
Presenter: Anvesh Dharanikota
Session: Poster Display
Resources:
Abstract
46P - Predicting toxicity following cancer chemotherapy by detecting transporter gene ABCB1 (C1236T, G2677T/A, C3435CT) polymorphism in breast cancer patients receiving chemotherapy with anthracycline and taxane either sequentially or concomitantly
Presenter: Tanuma Mistry
Session: Poster Display
Resources:
Abstract
47P - Sequencing of chemotherapy and surgery among older triple-negative and HER2-positive breast cancer patients with comorbidities
Presenter: Anvesh Dharanikota
Session: Poster Display
Resources:
Abstract
48P - The impact of preoperative axillary ultrasound on the false negative rate of sentinel lymph node biopsy in post neoadjuvant chemotherapy breast cancer patients
Presenter: Byshetty Rajendar
Session: Poster Display
Resources:
Abstract