The healthcare value of the Magee Decision Algorithm™: use of Magee Equations™ and mitosis score to safely forgo molecular testing in breast cancer

Abstract

Magee Equations™ are multivariable models that can estimate oncotype DX® Recurrence Score, and Magee Equation 3 has been shown to have chemopredictive value in the neoadjuvant setting as a standalone test. The current study tests the accuracy of Magee Decision Algorithm™ using a large in-house database. According to the algorithm, if all Magee Equation scores are <18, or 18-25 with a mitosis score of 1, then oncotype testing is not required as the actual oncotype recurrence score is expected to be ≤25 (labeled "do not send"). If all Magee Equation scores are 31 or higher, then also oncotype testing is not required as the actual score is expected to be >25 (also "do not send"). All other cases could be considered for testing (labeled "send"). Of the 2196 ER+, HER2-negative cases sent for oncotype testing, 1538 (70%) were classified as "do not send" and 658 (30%) as "send". The classification accuracy in the "do not send" group was 95.1%. Of the 75 (4.9%) discordant cases (expected score ≤25 by decision algorithm but the actual oncotype score >25), 26 received endocrine therapy alone. None of these 26 patients experienced distant recurrence (average follow-up of 73 months). The Magee Decision Algorithm accurately identifies cases that will not benefit from oncotype testing. Such cases constitute~70% of the routine clinical oncotype requests, an estimated saving of $300,000 per 100 test requests. The occasional discordant cases (expected ≤25, but actual oncotype score >25) appears to have an excellent outcome on endocrine therapy alone.

Luminal Breast Cancer: Risk of Recurrence and Tumor-Associated Immune Suppression

“…So far, a variety of gene-expression-profiling methods, such as Oncotype DX [36], MammaPrint [37], PAM50 [38], Breast Cancer Index [39], PREDICT score [40,41], IHC4score [42,43], Clinical Treatment Score (CTS) [44], Magee equation [45], and EndoPredict [46] have been developed to increase the accuracy on the prediction of the risk of recurrence, in order to guide treatment decisions (mainly adjuvant CT vs. no) in luminal subtypes. Unfortunately, none of these tests are currently used in clinical practice.…”

Gene expression signatures for tailoring adjuvant chemotherapy of luminal breast cancer: the pathologists' perspective

“…However, uptake by clinicians is not uniform. Some question the definition of 'high clinical risk', others argue that similar information can be obtained from in-house assessment of the Ki67 index or from other alternatives like MAGEE-equations [7]. How individual GEP assays have been constructed is not generally known by many physicians and the perception that GEP assays are interchangeable is widespread, a perception that is not substantiated by evidence when stratifying patients into risk categories.…”

Personalising therapy for early-stage oestrogen receptor-positive breast cancer in older women

“… 70 – 72 A decision algorithm (Magee Decision Algorithm) has been described using Magee Equations data and mitosis scores to safely forgo molecular testing in 70% of cases sent for recurrence score testing. 73 , 74 Evaluating the same dataset, we looked at the performance of the Magee Decision Algorithm in older patients (≥70 years). 73 The dataset contained 350 older patients, of which 244 (70%) were classified, using the Magee Decision Algorithm, as: low-risk recurrence and not requiring oncotype testing.…”