The Correlation of Magee Equations and Oncotype DX Recurrence Score in Mexican Patients Diagnosed with Early Breast Cancer

Purpose: Magee equations (MEs) can adequately predict Oncotype Dx (ODX) recurrence scores among specific patients with early stage breast cancer (EBC).Nonetheless, MEs have never been previously assessed in Hispanic patients in Latin America.The objective of this study was to evaluate the correlation between MEs and ODX among a cohort of Mexican patients with EBC.Methods: We performed a single-center retrospective cohort among patients with invasive EBC treated between January 2008 and December 2022.Patients with 0-3 lymph nodes, positive hormone receptors, and negative HER2 who had an ODX RS on file were included.Data was collected from medical files to calculate MEs and correlate with ODX score.Results: 98 patients fulfilled the criteria and were included in the analysis.Mean age was 57.8 years (S.D. 11.13); most patients had clinical stage IA (43.9%) and IIA (47.9%) disease.The median ODX RS was 15, and most patients were catalogued as low and intermediate risk (N=85; 86.7%).Meanwhile, mean MEs score was 16.6 for all participants.Concordance using the MES average was 79.6%, sensitivity was 93.3% and specificity 34.8%.Interestingly, concordance increased to 86.7% when using only the result from the ME3 equation, with 95.0% sensitivity and 50% specificity.Conclusion: In Mexican patients with early EBC, the results from MEs correlate with ODX score, highlighting these as a potential tool to discriminate between cases which require genetic profiling and those which can forego testing.This data warrants validation in prospective studies amongst patients with BC in Latin America.