Using the Modified Magee Equation to Identify Patients Unlikely to Benefit From the 21-Gene Recurrence Score Assay (Oncotype DX Assay)

Objectives: This study aimed to compare a modified Magee equation with Oncotype DX (Genomic Health, Redwood City, CA) recurrence score (RS) and identify patients who are unlikely to benefit from Oncotype DX. Methods: Magee equation RS was calculated in 438 cases and correlated with Oncotype DX RS. Results: The Pearson correlation coefficient (r) for the Magee equation and Oncotype DX RS was 0.6645 (P<.00001), and the overall agreement was 66.4%. All cases (11.6%) with a Magee equation RS greater than 30 or 11 or less had been correctly predicted to have either high Oncotype DX RS or low Oncotype DX RS, respectively. Conclusions: The modified Magee equation is able to identify up to 12% patients who are unlikely to benefit from Oncotype DX testing. Using the modified Magee equation RS on these patients would be an alternative to Oncotype DX, leading to cost savings.