Julia Blanter1, Brittney Zimmerman2, Serena Tharakan3, Meng Ru2, Krystal Cascetta2, Amy Tiersten2. 1. Internal Medicine Department, Icahn School of Medicine at Mount Sinai, New York, New York, USA, jblanter@gmail.com. 2. Hematology/Oncology Department, Icahn School of Medicine at Mount Sinai, New York, New York, USA. 3. Internal Medicine Department, Icahn School of Medicine at Mount Sinai, New York, New York, USA.
Abstract
BACKGROUND: The Oncotype DX Breast Cancer Assay is a 21-gene assay used to predict the likelihood of distant recurrence and the benefit of chemotherapy in patients with node-negative, tamoxifen-treated breast cancer. Prior studies demonstrated 7-19% discordance, or a difference between the recurrence score (RS) and tumor grade (TG) in breast cancer patients. BRCA mutated tumors (BRCA+) have been shown to be associated with higher RS as compared to BRCA-negative patients (BRCA-). OBJECTIVES: We developed a large Oncotype RS database to determine if the BRCA mutation status is associated with discordance. METHODS: We identified 723 patients (32 [4%] mutation-positive and 691 [96%] mutation-negative patients) with early-stage, hormone-positive breast cancer treated between 2006 and 2018, with tumor characteristics available for analysis. Discordance was defined as one- or two-step difference between RS (low, intermediate, high risk) and TG (well [WD], moderately [MD], and poorly [PD] differentiated). Mutation positive was defined as BRCA1 deleterious mutation, BRCA2 deleterious mutation, BRCA mutation of unknown type, BRCA variant of undetermined significance (VUS) or other mutation (classified as other VUS). Number (%) or median were used to describe patient characteristics between groups and were compared by the Kruskal-Wallis test at a significance level of 5%. RESULTS: Among these patients, there were 32 (4% of total) who were identified as mutation-positive. Of those patients, 16% had a documented deleterious mutation in BRCA1, 22% in BRCA2, 6% had a BRCA mutation of unknown type (either 1 or 2), 25% were BRCA VUS, and 31% other VUS (most commonly CHEK2 and ATM). The median RS was 23.5 in patients with deleterious BRCA mutations (1, 2 or unknown) versus 16 in patients in the BRCA-negative database, which was statistically significant (p < 0.01). One- and two-step discordance was present in 46 and 8%, respectively, of patients with deleterious BRCA mutations versus 53 and 11%, respectively, in the BRCA-negative database. CONCLUSIONS: Patients with deleterious BRCA mutations demonstrated no difference in rates of discordance as compared to BRCA-negative patients. We further demonstrated that patients with BRCA-positive tumors display higher RS than patients with BRCA-negative tumors.
BACKGROUND: The Oncotype DX Breast Cancer Assay is a 21-gene assay used to predict the likelihood of distant recurrence and the benefit of chemotherapy in patients with node-negative, tamoxifen-treated breast cancer. Prior studies demonstrated 7-19% discordance, or a difference between the recurrence score (RS) and tumor grade (TG) in breast cancerpatients. BRCA mutated tumors (BRCA+) have been shown to be associated with higher RS as compared to BRCA-negative patients (BRCA-). OBJECTIVES: We developed a large Oncotype RS database to determine if the BRCA mutation status is associated with discordance. METHODS: We identified 723 patients (32 [4%] mutation-positive and 691 [96%] mutation-negative patients) with early-stage, hormone-positive breast cancer treated between 2006 and 2018, with tumor characteristics available for analysis. Discordance was defined as one- or two-step difference between RS (low, intermediate, high risk) and TG (well [WD], moderately [MD], and poorly [PD] differentiated). Mutation positive was defined as BRCA1 deleterious mutation, BRCA2 deleterious mutation, BRCA mutation of unknown type, BRCA variant of undetermined significance (VUS) or other mutation (classified as other VUS). Number (%) or median were used to describe patient characteristics between groups and were compared by the Kruskal-Wallis test at a significance level of 5%. RESULTS: Among these patients, there were 32 (4% of total) who were identified as mutation-positive. Of those patients, 16% had a documented deleterious mutation in BRCA1, 22% in BRCA2, 6% had a BRCA mutation of unknown type (either 1 or 2), 25% were BRCA VUS, and 31% other VUS (most commonly CHEK2 and ATM). The median RS was 23.5 in patients with deleterious BRCA mutations (1, 2 or unknown) versus 16 in patients in the BRCA-negative database, which was statistically significant (p < 0.01). One- and two-step discordance was present in 46 and 8%, respectively, of patients with deleterious BRCA mutations versus 53 and 11%, respectively, in the BRCA-negative database. CONCLUSIONS:Patients with deleterious BRCA mutations demonstrated no difference in rates of discordance as compared to BRCA-negative patients. We further demonstrated that patients with BRCA-positive tumors display higher RS than patients with BRCA-negative tumors.
Authors: Rachel M Layman; Heather Lin; Angelica M Gutierrez Barrera; Meghan S Karuturi; Clinton Yam; Banu K Arun Journal: Cancer Med Date: 2022-02-06 Impact factor: 4.452