Receptor-positive Node-negative Breast Research Articles

Abstract PO1-01-12: A retrospective cohort study on the effect of adding adjuvant ovarian function suppression to endocrine therapy in premenopausal women with T1-T2 tumor hormone-positive breast cancer on survival and disease recurrence

Abstract Background: Breast cancer is the most common diagnosed cancer in women and is the leading cause of cancer death. Young women diagnosed with breast cancer are at higher rates of adverse outcomes in terms of survival and recurrence. Hormone sensitive breast cancer is the commonest subtype of breast cancer in this group. To date, the standard adjuvant treatment is endocrine therapy for both pre and post-menopausal women. Recent published studies have recommended adding ovarian function therapy to premenopausal women who are at high risk of recurrence. In this study we evaluated the impact of adding adjuvant ovarian function suppression for premenopausal women with small (T1 and T2) hormone receptor positive node negative breast cancer who did not receive any form of chemotherapy on overall survival and disease-free recurrence. Methods: We performed a retrospective study where we evaluated the electronic medical records of 4431 premenopausal women diagnosed with breast cancer in Asan Medical Center in Seoul, South Korea. All the analyzed patients were operated from the period of January 2006 till December 2019. The inclusion criteria were age of 55 and below, T1 and T2 tumors with N0 disease who received selective estrogen receptor modulators (SERM - Tamoxifen) and didn’t receive neo or adjuvant chemotherapy. We compared patients who received SERM (Tam Only) only to patients who received SERM and ovarian function suppression (Tam + OFS) medications. The primary endpoint was overall survival (OS), and the secondary endpoint was mortality and disease-free survival (DFS). We used chi-square test for categorical variables and t-test for continuous variables. The p-value was set as p< 0.05 as statistically significant. Kaplan Meier curve and log rank test were used to analyze the data for overall survival, disease-free survival and mortality. We performed an additional subgroup analysis adjusted to age, tumor size, Ki67%, progesterone receptor, HER2 status and type of operation. Results: There was equal distribution of cases between tamoxifen only group and tamoxifen + OFS group (2121 versus 2310 respectively). The median age in each group was 45 years of age. Tumor size of ≤0.5cm was the commonest in the tamoxifen only group whereas tamoxifen + OFS group had majority of cases with tumor size of 1 - 2cm. Both groups had a Ki-67% of 10-20%. Histologic grade of 2 and nuclear grade of 2 were most commonly representative in the comparing groups. Invasive ductal carcinoma was the most common histological subtype (93-94%) and invasive lobular carcinoma accounted for 5-6% of cases. Regarding immunohistochemistry results, 91-93% of patients were progesterone receptor positive and 68-73% were HER2 negative. The majority underwent breast conserving surgery compared to mastectomy. We have also looked at the pattern of prescribing OFS treatment in the Tamoxifen + OFS group regarding the length of treatment. Nearly 80% of patients received OFS treatment for a period of 1-2 years whereas only 5.2% received < 1 year and 1.8% >2years. After adjusting to age, tumor size, Ki67%, PR receptor and HER2 status, the result was only significant for higher risk of DFS in the TAM + OFS group in Ki67 < 20%. The OFS+TAM had more DFS and mortality events compared to TAM only group. However, the only significant result was the overall survival favoring tamoxifen only group with a p-value of 0.039 and HR of 1.05-7.99. Conclusion: Adding ovarian function suppression to tamoxifen in premenopausal hormone positive node negative T1-T2 tumors didn’t show any benefit in terms of disease-free interval and overall survival. Further studies are advised to assess the benefit of adding ovarian function suppression to this group of patients Table 1: baseline characteristics of Table 2: Disease Free Survival Subgroup Analysis Citation Format: Sarah Al Safi, Hee Jeong Kim, Seonok Kim, Sae Byul Lee, Jisun Kim, Tae-Kyung Yoo, Il-Yong Chung, Beom Seok Ko, Byung Ho Son. A retrospective cohort study on the effect of adding adjuvant ovarian function suppression to endocrine therapy in premenopausal women with T1-T2 tumor hormone-positive breast cancer on survival and disease recurrence [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-01-12.

Abstract P4-08-27: The 21-gene Recurrence® (RS) Score assay in estrogen receptor positive node negative breast cancer: Real-world chemotherapy usage and patient characteristics within the intermediate and high-risk RS category

Abstract Background: The Oncotype Dx, a 21-gene recurrence score (RS) assay, has been validated as a prognostic tool in early-stage, hormone receptor-positive, HER2-negative breast cancer. A RS of ≥ 31 is predictive for chemotherapy benefit. However, it has not been clearly established whether more intensive chemotherapy regimens for these patients provide further benefit and whether higher RS stratifications (≥41) influence treatment decisions. Methods: From the prospective British Columbia (BC) Breast Cancer Outcomes Unit database, we identified patients with N0 disease who received Oncotype Dx testing from May 2010 to December 2016. Patients with previous or synchronous breast cancer, and patients treated with neoadjuvant chemotherapy were excluded. Groups were defined that had an Oncotype Dx RS of 31-40 and ≥ 41. Demographic characteristics and type of chemotherapy received were collected. Additional subgroups were defined for patients who had a RS of 21-25 and who were ≤ 50 years old and > 50 years old. Results: We identified 1,202 patients who received Oncotype Dx testing over the time period studied, with 14.8% (n=178) having a RS of ≥ 31. Among these high-risk patients, the median age was 58 (range 34-79), 90% received hormonal therapy and 85% received chemotherapy. In this cohort, 46% received docetaxel and cyclophosphamide for 4 cycles and 28% received 3rd generation chemotherapy. The use of 3rd generation chemotherapy in patients with a RS of ≥ 41 was significantly higher than in patients with RS between 31-40 (39% vs 22%, p = 0.006). Among patients who had a RS of 21-25 and who were ≤ 50 years old (n = 49), 53% received chemotherapy. Of patients who had a RS of 21-25 and who were > 50 years old (n = 127), 16% received chemotherapy. Conclusions: Among patients with a RS ≥ 31, decisions regarding chemotherapy usage were heterogeneous with docetaxel and cyclophosphamide for 4 cycles being the most commonly used regimen. However, in those with a RS ≥ 41, 3rd generation chemotherapy was preferred. Patients with a RS between 21-25 and who were ≤ 50 years old received more chemotherapy than patients who were > 50 years old. RS 31-40 (n=116)RS ≥ 41 (n=62)RS ≥ 31 (n=178)Median age58.0 (range, 36-79)57.5 (range 34-78)58.0 (range 34-79)Pre-menopausal28.4%29.0%28.7%Hormonal therapy93.1%83.9%89.9%Chemotherapy86.2%82.3%84.8%DCx4 (1)54.3% (n=63/116) Median age 59.0 (range, 36 – 78)30.6% (n=19/62) Median age 64.0 (range, 42 – 78)46.1% (n=82/178) Median age 59.5 (range, 36 – 78)3rd generation chemo (2)21.6% (n=25/116) Median age 56.0 (range, 39 – 79)38.7% (n=24/62) Median age 52.0 (range, 34 – 76)27.5% (n=49/178) Median age 54.0 (range, 34 – 79)Other chemo10.3% (n=12/116) Median age 57.5 (range, 52 – 78)12.9% (n=8/62) Median age 64.0 (range, 42 – 72)11.2% (n=20/178) Median age 58.5 (range, 42 – 78)(1) Docetaxel and cyclophosphamide, 4 cycles (2) Anthracycline and Taxane containing regimens, 6 cycles or 8 cycles Citation Format: Le D, Chia S, Simmons C, Speers C, Gondara L, Nichol A, Lohrisch C, Gelmon KA. The 21-gene Recurrence® (RS) Score assay in estrogen receptor positive node negative breast cancer: Real-world chemotherapy usage and patient characteristics within the intermediate and high-risk RS category [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-08-27.

A prospective clinical utility and pharmacoeconomic study of the impact of the 21-gene Recurrence Score® assay in oestrogen receptor positive node negative breast cancer

PurposeThe primary purpose of this study was to measure the impact of the 21-gene Recurrence Score® result on systemic treatment recommendations and to perform a prospective health economic analysis in stage I–II, node-negative, oestrogen receptor positive (ER+) breast cancer. MethodsConsenting patients with ER+ node negative invasive breast cancer and their treating medial oncologists were asked to complete questionnaires about treatment preferences, level of confidence in those preferences and a decisional conflict scale (patients only) after a discussion of their diagnosis and risk without knowledge of the Recurrence Score. At a subsequent visit, the assay result and final treatment recommendations were discussed prior to both parties completing a second set of questionnaires. A Markov health state transition model was constructed, simulating the costs and outcomes experienced by a hypothetical ‘assay naïve’ population and an ‘assay informed’ population. ResultsOne hundred and fifty-six patients across two cancer centres were enrolled. Of the 150 for whom successful assay results were obtained, physicians changed their chemotherapy recommendations in 45 cases (30%; 95% confidence interval (CI) 22.8–38.0%); either to add (10%; 95% CI 5.7–16.0%) or omit (20%; 95% CI 13.9–27.3%) adjuvant chemotherapy. There was an overall significant improvement in physician confidence post-assay (p<0.001). Patient decisional conflict also significantly decreased following the assay (p<0.001). The simulation model found an incremental cost-effectiveness ratio of Canadian Dollars (CAD) $6630/quality-adjusted life years (QALY). ConclusionWithin the context of a publicly funded health care system, the Recurrence Score assay significantly affects adjuvant treatment recommendations and is cost effective in ER+ node negative breast cancer.

P202 Gross financial evaluation of the application of the 21-gene assay Oncotype DX for adjuvant chemotherapy decision-making in estrogen receptor-positive node negative breast cancer in Greece

P202 Gross financial evaluation of the application of the 21-gene assay Oncotype DX for adjuvant chemotherapy decision-making in estrogen receptor-positive node negative breast cancer in Greece