Abstract 1156
Background
Decision on adjuvant chemotherapy for early breast cancer can be guided by genomic assays. PREDICT is a validated free online tool that estimates the benefit from adjuvant chemotherapy using clinical and pathological data. The concordance of expected clinical decisions guided by Oncotype analysis and the PREDICT in unknown.
Methods
A retrospective single center cohort study comprising all women with estrogen receptor (ER) positive, human epidermal growth factor receptor 2 negative, node negative disease, whose tumors were sent for OncotypeDX analysis. Estimation of 10-year overall survival (OS) benefit from 2nd generation chemotherapy was calculated using the PREDICT 2.1v tool. Omission of chemotherapy was expected to be advised when Oncotype recurrence score (RS) was ≤25 or when the estimated 10-year OS benefit by the PREDICT was <2%. The tests were considered concordant for women with RS ≤ 25 and estimated PREDICT benefit<2% or for women with RS > 25 and estimated PREDICT benefit ≥2%. Concordance was presented using percentages and the K coefficient. The impact on concordance of pre-specified histological features was assessed, including tumor size, intensity of ER and progesterone receptor (PR), grade, Ki67 and perineural and lymphovascular invasion. The difference between the subgroups was calculated using Chi-squared test.
Results
A total of 445 women were included. Overall concordance was 75% (K = 0.284), with 55 (12.5%) women with low RS but estimated PREDICT benefit ≥2% and 55 (12.5%) with high RS and estimated PREDICT benefit<2%. The concordance was significantly higher for grade 1 disease compared to grade 2-3 (93% vs 72%, p < 0.001), tumor ≤1cm compared to > 1cm (85% vs 72%, p = 0.009), PR positive compared to PR negative (78% vs 58%, p < 0.001) and ki67<20% compared to ≥ 20% (82% vs 54%, p < 0.001). The intensity of ER and the presence of perineural or lymphovascular invasion had no significant impact on concordance.
Conclusions
Compared to PREDICT, using Oncotype in node negative, ER positive disease is expected to change clinical decision in a quarter of patients. The concordance is influenced by pathological features. The use of Oncotype may not be necessary for clinically very low risk patients.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
H. Goldvaser: Honoraria (self): Roche. R. Yerushalmi: Honoraria (self): Roche; Honoraria (self): Medison; Honoraria (self): AstraZeneca; Honoraria (self): Novartis; Honoraria (self): Teva. M. Sarfaty: Honoraria (self): Roche; Honoraria (self): MSD; Honoraria (self): Medison; Honoraria (self): Novartis. All other authors have declared no conflicts of interest.
Resources from the same session
3330 - Tumour-infiltrating lymphocytes and BRCA-like status in stage III breast cancer patients treated with intensified carboplatin-based chemotherapy
Presenter: Leonora De Boo
Session: Poster Display session 2
Resources:
Abstract
3971 - Unravelling the biological characteristics of MammaPrint extreme risk subgroups
Presenter: Rajith Bhaskaran
Session: Poster Display session 2
Resources:
Abstract
5871 - Residual Cancer burden as a prognostic factor in a large series of Neoadjuvant chemotherapy. Subgroup analysis per molecular surrogated subtypes
Presenter: Catalina Falo
Session: Poster Display session 2
Resources:
Abstract
5014 - Clinical validation of CanAssist Breast in a Spanish cohort
Presenter: Manjiri Bakre
Session: Poster Display session 2
Resources:
Abstract
2787 - Meta-analysis on association of pathological complete response with long-term survival outcomes in triple-negative breast cancer
Presenter: Peter A. Fasching
Session: Poster Display session 2
Resources:
Abstract
4301 - Immune infiltrate composition across intrinsic subtypes in hormone receptor (HR)+/HER2- early breast cancer (BC) enrolled in the prospective LETLOB trial
Presenter: Gaia Griguolo
Session: Poster Display session 2
Resources:
Abstract
3205 - Frequency of germline mutations in women's cancer susceptibility genes in a large cohort of Chinese breast cancer patients
Presenter: Ning Liao
Session: Poster Display session 2
Resources:
Abstract
4091 - Triple blinded Prospective Study assessing the Impact of Genomics & Artificial Intelligence Watson For Oncology (WFO) on MDT’s Decision of Adjuvant Systemic Therapy for Hormone Receptor Positive Early Breast Carcinoma-
Presenter: Somashekhar Sampige Prasannakumar
Session: Poster Display session 2
Resources:
Abstract
4359 - Prognostic significance of Progesterone Receptor levels in luminal-like Her2- early Breast Cancer patients. A retrospective single Cancer Center analysis.
Presenter: Anna Diana
Session: Poster Display session 2
Resources:
Abstract
1369 - PAM50 HER2-enriched subtype and pathological complete response in HER2-positive early breast cancer: a meta-analysis
Presenter: Francesco Schettini
Session: Poster Display session 2
Resources:
Abstract