Abstract P4-06-07: Clinical risk-assessment, risk-stratification, and outcomes of ER positive, HER2 negative breast cancer patients using the Rochester modified Magee algorithm (RoMMA)

Abstract

Abstract INTRODUCTION: In 2013, Klein and Dabbs et al. published three linear regression equations (the new Magee equations) using different combinations of standard histopathologic variables. In 2015, our group published a modification of the new Magee equations. Based on this modification, we published an algorithmic approach using an average Modified Magee equation. This algorithmic approach supported reflex Oncotype DX (ODX) testing based on several cutoff points using an average Modified Magee score. In 2019, we validated this algorithmic approach as the Rochester Modified Magee Algorithm (RoMMA) in a multi-institutional study, with outcome data in 247 patients, suggesting that ER positive breast cancer patients with an average Modified Magee score of ≤ 12 had a low risk of breast cancer recurrence. There has been limited published outcome data on the Magee equation since that 2019 study. We have further refined our risk-stratification approach, with additional outcome data in 416 ER positive breast cancer patients. METHODS: 416 patients with an ODX recurrence score who had at least five years of follow-up data or a breast cancer recurrence were included in the final outcome analysis (2008-2017). All patients received either Tamoxifen or an aromatase inhibitor. None of the patients received adjuvant systemic chemotherapy. The average Modified Magee score was calculated and patients were stratified into four risk-stratification categories: 1) very low, 2) low ≤ 50 years of age, 3) low > 50 years of age, and 4) high. We compared these four risk-stratification categories, with outcomes, between the average Modified Magee score and the ODX recurrence score. A p-value of < 0.05 was considered statistically significant. RESULTS: 27/416 (6.5%) patients had a recurrence of breast cancer. When comparing the same risk category groups, there was no significant difference between the average Modified Magee score and the ODX recurrence score (Table 1). CONCLUSION: Our study further reinforces that breast cancer patients can be confidently stratified into low and high risk recurrence groups using the average Modified Magee score. The average Modified Magee score may be an alternative to ODX for clinical risk-assessment and risk-stratification, particularly in lower risk patients, offering breast cancer patients increased access to clinical risk-assessment and risk-stratification, both domestically and internationally, with a potential significant cost savings for health care systems. A large prospective evaluation, similar to the studies done by ODX, using multi-institutional data or data from studies like the NSABP trial B-14 and the NSABP trial B-20, is necessary. Table 1.Risk-stratification categories and outcomes using the average Modified Magee score (aMMs) and the Oncotype DX recurrence score (ODXRS)RECURRENCENO RECURRENCEP-VALUEVERY LOW (N)aMMs ≤ 12 (76)1 (1.3)75 (98.7)0.65ODXRS < 11 (108)4 (3.7)104 (96.3)LOW ≤ 50 years of age (N)aMMs > 12, ≤ 18 (50)3 (6.0)47 (94.0)1.0ODXRS 11 - 15 (32)1 (3.1)31 (96.9)LOW >50 years of age (N)aMMs > 12, ≤ 18 (153)8 (5.2)145 (94.8)0.52ODXRS 11 - 25 (214)16 (7.5)198 (92.5)HIGH (N)aMMs > 18 (137)15 (10.9)122 (89.1)1.0ODXRS ≥ 16 - 25 (33)* and ODXRS > 25 (29)**6 (9.7)56 (90.3)* Patients ≤ 50 years of age with an ODXRS of ≥16 - 25. ** All patients with an ODXRS of > 25 Citation Format: Numbereye Numbere, Ioana Moisini, Ajay Dhakal, Kristin Skinner, Michelle Shayne, Mary Ann Gimenez Sanders, Huina Zhang, David Hicks, Bradley M Turner. Clinical risk-assessment, risk-stratification, and outcomes of ER positive, HER2 negative breast cancer patients using the Rochester modified Magee algorithm (RoMMA) [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P4-06-07.