Abstract P3-07-06: ER+ patients with an average modified Magee score ≤ 18 have a low likelihood of breast cancer recurrence and a high likelihood of an Oncotype Dx® recurrence score < 26

Abstract

Abstract INTRODUCTION: The recent TAILORx results suggest that adjuvant endocrine therapy and chemoendocrine therapy had similar efficacy in women with hormone-positive, HER2-negative, node-negative invasive breast carcinomas with an Oncotype Dx® recurrence score < 26. Oncotype Dx® is an expensive test (current list price of $4,620.00). Although the Oncotype Dx® test has gained widespread acceptance, cost may be an impediment to its adoption in certain areas of the world, and it may not be the most cost-effective or cost-efficient option in certain subsets of breast cancer patients. Based on a modification of the new Magee equations, we published an algorithmic approach in 283 ER+ cases using an average modified Magee equation (Turner BM, et al. Mod Pathol. 2015;28(7):921-31), and subsequently published a validation of this algorithmic approach in an additional 620 ER+ cases (Cancer Med. 2019 Jun 14. doi: 10.1002/cam4.2323. [Epub ahead of print]), supporting only reflex Oncotype Dx® testing for certain subsets of breast cancer patients. We now have recurrence data and at least five years of outcome data on 310 cases. METHODS: A total of 310 cases with ER+ invasive breast cancer, all with Oncotype Dx® recurrence scores, were included in this study from the University of Rochester and the University of Louisville. The outcome analysis included all patients who had at least five years of follow-up data, and all patients who had a breast cancer recurrence. In order to calculate the average modified Magee score, information on the Nottingham score, ER, PR, Ki-67, HER-2, and tumor size was extracted from the pathology report. RESULTS: 255/310 cases had an Oncotype Dx® < 26, and 4% (10/255) of these cases were associated with a breast cancer recurrence. 187/310 cases had an average modified Magee score ≤ 18, and 184 of these 187 cases (98%) had an Oncotype Dx® recurrence score < 26. Only 2% (n = 4) of these 184 cases were associated with a breast cancer recurrence. On average, the Nottingham score and Ki-67 were lower for cases with an average modified Magee score ≤ 18 compared to cases with an Oncotype Dx® recurrence score < 26 (Table 1). On average, the modified ER and PR H-scores were higher for cases with an average modified Magee score ≤ 18 compared to cases with an Oncotype Dx® recurrence score < 26 (Table 1). CONCLUSION: If the average modified Magee score is ≤ 18, the patient has a low likelihood of recurrence, and the Oncotype Dx® recurrence score will likely be < 26. Given the recent TAILORx findings, we suggest that patients with an average modified Magee score ≤ 18 not be sent out for Oncotype Dx® testing if an Oncotype Dx® recurrence score < 26 is the basis on which the clinician will use to decide whether or not to give chemotherapy. The information needed to use the average modified Magee equation is already generated by many pathology laboratories during the initial assessment of breast cancer, and the Magee equations are free of charge (https://path.upmc.edu/onlineTools/mageeequations.html). Based on the Genomic Health 2017 Annual Report, our data suggests that not sending out cases with an average modified Magee score ≤ 18 would have resulted in a potential cost savings to the health-care system in 2018 of almost 300 million dollars. Table 1: Average Nottingham score, modified ER H-score, modified PR H-score, and Ki-67, with number and percent recurrence for cases with an average modified Magee score ≤ 18 and cases with an Oncotype Dx® recurrence score < 26AVERAGERecurrence Sore typeNNS**ER***PR***Ki-67Recurrence N (%)Average modified Magee score ≤ 18*1875.2262.3235.410.34 (2)Oncotype Dx® recurrence score < 262555.5253.2192.613.610 (4)*98% (184/187) of patients with an average modified Magee score ≤ 18 had an Oncotype Dx® recurrence score < 26**Nottingham score***modified H-score (Turner BM, et al. Mod Pathol. 2015;28(7):921-31) Citation Format: Hasan Khatib, Mary Ann G Sanders, Andrea Breaux, Armen Soukiazian, Nyrie Soukiazian, David Hicks, Bradley M Turner. ER+ patients with an average modified Magee score ≤ 18 have a low likelihood of breast cancer recurrence and a high likelihood of an Oncotype Dx® recurrence score < 26 [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P3-07-06.