Abstract 23P
Background
Oncotype DX RS estimates the likelihood of recurrence and predicts the benefit from chemotherapy in early HR positive, node negative breast cancer. Patients are categorized into one of three tiers based on a calculated recurrence score (RS); low (<18), intermediate (18–30), and high (≥31–100). 2008 NCCN guidelines recommended adjuvant endocrine therapy for low RS, adjuvant chemoendocrine therapy for high RS. There was no clear chemotherapy recommendation for intermediate RS. In 2018 the TAILORx re-established RS categories; a score of less than 11 is low, 11-25 is intermediate and 26-100 is high, and provided evidence to treat patients with intermediate RS. We are Studying Oncotype Dx RS correlation with clinic-pathologic risk factors, and chemotherapy based on TAILORx tiers. We also looked the characteristics of patients with cancer recurrence.
Methods
Retrospective review of patients who had Oncotype DX test during 2012-2017 at National Cancer Center–Qatar.
Results
Of 54 patients studied 16(29.63%) had low RS, 32(59.26%) had intermediate RS, and 6(11.1%) had high RS. Univariate analysis showed that age (p<0.014), tumor grade (p<0.034), and Ki67% (cut-off 20%; p<0.013) were significantly different among Oncotype DX RS categories. There was no significant difference among Oncotype DX RS categories for tumor size (p<0.288) or PR status (cut-off 1%, p<0.3). Multivariate analysis showed that none of the clinical/pathological factors significantly predict the Oncotype DX RS. Chemotherapy was given to 1/16 (6.25%) patients with low, 7/32(21.9%) patients with intermediate, and 4/6 (66.7%) patients with high Oncotype DX RS (univariate analysis p<0.01). Tumor size was the only predictor of chemotherapy in multivariate analysis (OR 2.33 CI 0.33 - 3.86, p<0.020). 75% of patients who relapsed had RS 16-25, and were less than 50 years old in age.
Conclusions
Oncotype RS correlates significantly with individual clinical risk factors including age, tumor grade, Ki67%, chemotherapy treatment. Tumor size significantly predicts adjuvant chemotherapy. Breast cancer recurrence was noticed in younger patients with high intermediate RS (16-25), and adjuvant chemotherapy may be a reasonable option for these patients.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
420TiP - UpSwinG: Real-world study of TKI activity in patients with EGFR mutation-positive (EGFRm+) NSCLC with uncommon mutations, and sequencing of afatinib followed by osimertinib
Presenter: Satoru Miura
Session: e-Poster Display Session
443TiP - A multicenter, open-label, randomized phase II study to compare the efficacy and safety of lenvatinib in combination with ifosfamide and etoposide versus ifosfamide and etoposide in children, adolescents, and young adults with relapsed or refractory osteosarcoma (OLIE; ITCC-082)
Presenter: Nathalie Gaspar
Session: e-Poster Display Session
7P - Machine learning intratumoral and axillary lymph node magnetic resonance imaging radiomics for predicting axillary lymph node metastasis in patients with early-stage invasive breast cancer (RBC-01 Study)
Presenter: Yujie Tan
Session: e-Poster Display Session
8P - Knowledge, practice and attitudes of physicians in low- and middle-income countries (LMIC) on fertility and pregnancy-related issues in young breast cancer patients
Presenter: Shah Zeb Khan
Session: e-Poster Display Session
9P - Survival status of elderly women with HR+ early breast cancer: An analysis of SEER database
Presenter: Wang Hao
Session: e-Poster Display Session
10P - Neoadjuvant immunotherapy plus chemotherapy in early triple-negative breast cancer: A meta-analysis of randomized controlled trials
Presenter: Jessa Gilda Pandy
Session: e-Poster Display Session
11P - Genetically predicted bipolar disorder is causally associated with increased risk of breast cancer: A Mendelian randomization analysis
Presenter: Haoxin Peng
Session: e-Poster Display Session
12P - Stromal tumour-infiltrating lymphocytes in human epidermal growth factor receptor 2-overexpressing breast cancer: Association with negative nodal metastasis
Presenter: Ren Xiaoqiu
Session: e-Poster Display Session
13P - A retrospective observational study on neoadjuvant chemotherapy in older adults based on the Joint Breast Cancer Registry Singapore
Presenter: Johan Chan
Session: e-Poster Display Session