Abstract 4631
Background
Determining which early stage breast cancer patients should receive chemotherapy is an important clinical and economic issue. Chemotherapy has many adverse side effects, impacting on quality of life, along with significant economic consequences. Biomarkers that can predict patient response to chemotherapy can help avoid ineffective overtreatment. The aim of this work is to assess if the OncoMasTR (OM) signature can predict pathological complete response (pCR) to neo-adjuvant chemotherapy, and to compare its predictive value with EndoPredict (EP) and Oncotype DX (RS).
Methods
Gene expression datasets derived from breast cancer patients that had pre-treatment biopsies, received neo-adjuvant chemotherapy and an assessment of pCR were obtained from GEO (GSE16716, GSE20271, GSE25066, GSE32646, GSE34138, GSE41998, GSE22226). Patients with ER-positive, HER2-negative disease and pCR data were selected. OM, EP and RS numeric risk scores were approximated by applying the gene coefficients to the corresponding mean probe expression values. Association with pCR was estimated using logistic regression.
Results
A total of 813 patients with 66 pCR events were included in the analysis. OM, EP and RS prognostic scores were moderately well correlated according to the Pearson’s correlation coefficient: OM vs EP (min=0.44; mean=0.67; max=0.81), OM vs RS (min=0.34; mean=0.62; max=0.79), and RS vs EP (min=0.55; mean=0.79; max=0.89). Significant predictors of pCR with p-values of 0.0001 for all three signatures. Odds ratios for a 1 standard deviation increase in risk score, adjusted for cohort, were similar in magnitude and not significantly different: OM 1.66 (1.29 to 2.16), EP 1.76 (1.37 to 2.27), RS 1.84 (1.44 to 2.35).
Conclusions
In this in silico analysis, OM, EP and RS prognostic scores were significantly predictive of pCR to neo-adjuvant chemotherapy in ER-positive, HER2-negative breast cancer. Optimal stratification for neo-adjuvant chemotherapy offers the opportunity for personalised care, improved therapy response rates, and reduced ineffective treatment and costs.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
University College Dublin.
Funding
The EI and from the European Union’s Horizon 2020 research and innovation programme under the Marie Slodowska-Curie grant agreement No. 713654.
Disclosure
The author has declared no conflicts of interest.
Resources from the same session
740 - A real-world analysis of the treatment of advanced ovarian cancer with PARPIs
Presenter: Alejandra Martinez de Pinillos
Session: Poster Display session 2
Resources:
Abstract
5867 - Incidence of tumour BRCA1/2 variants in relapsed, platinum-sensitive ovarian, fallopian tube and primary peritoneal cancer
Presenter: Robert Morgan
Session: Poster Display session 2
Resources:
Abstract
2966 - Frequency of mutations in 21 hereditary breast and ovarian cancer susceptibility genes among 882 high-risk individuals
Presenter: Jihong Liu
Session: Poster Display session 2
Resources:
Abstract
1687 - BRCA testing of 1,284 Brazilian patients for hereditary breast and ovarian cancer in a routine diagnostic setting
Presenter: Fernanda Milanezi
Session: Poster Display session 2
Resources:
Abstract
3162 - A multi-center integrative study on cancer predisposition genes in Chinese patients with epithelial ovarian carcinoma
Presenter: Changbin Zhu
Session: Poster Display session 2
Resources:
Abstract
5993 - Incidental Early Occult Ovarian Cancer after Risk-Reducing Salpingo-Oophorectomy in BRCA1/2 Mutation Carriers followed in a Community Public Hospital
Presenter: Begona Grana Suarez
Session: Poster Display session 2
Resources:
Abstract
5334 - Response to chemotherapy in ovarian cancer (OC) patients with or without prior breast cancer (BC), stratified by BRCA mutation (BRCAm) status
Presenter: Angela George
Session: Poster Display session 2
Resources:
Abstract
4565 - Advanced ovarian cancer: is residual disease after debulking surgery affected by genetics factors involved in angiogenesis and immunity pathways?
Presenter: Michele Bartoletti
Session: Poster Display session 2
Resources:
Abstract
3251 - Surrogate endpoint of progression-free (PFS) and overall survival (OS) for advanced ovarian cancer (AOC) patients (pts) treated with neo-adjuvant chemotherapy (NACT): Results of the CHIVA randomized phase II GINECO study
Presenter: Fabrice Lecuru
Session: Poster Display session 2
Resources:
Abstract
3278 - Immune-Related Gene Expression Profiling after Neoadjuvant Chemotherapy (NACT) of Ovarian High-Grade Serous Carcinoma
Presenter: Luis Manso
Session: Poster Display session 2
Resources:
Abstract