Comparative analysis of genomic tests for the prediction for late recurrence risk in hormone receptor–positive invasive breast cancer in a sample of Colombian patients.

e13092 Background: Approximately 70% of invasive breast cancers are hormone receptor-positive, requiring 5 years of endocrine therapy as the gold standard treatment. However, extended endocrine therapy (EET) may be needed, considering the late recurrence risk up to 15 years post-diagnosis. Different genomic tests predict the risk of recurrence. The 70-gene signature classifies patients as low or high risk during the first 5-years after diagnosis. The 12-gene test identifies high and low-risk patients for distant relapse up to 15 years, while a third test, based on 7-gene expression, assesses distant relapse risk up to 10 years. These tests assist clinicians in defining the need for EET. This study aims to compare the results of these genomic tests to determine late recurrence and distant relapse risks after 5 years, guiding EET indications. Methods: This is a retrospective descriptive transversal study involving 27 female patients diagnosed with hormone receptor-positive invasive breast cancer, treated in the same oncologic center in Colombia. All patients were first tested with the 70-gene genomic profile, with 15 patients undergoing the 12-gene test and 12 cases undergoing the 7-gene assay approximately 5 years later. Concordance between test results was assessed, and socio-demographic variables were descriptively analyzed. Results: The mean age was 54.4 years (SD=11.7). Invasive ductal carcinoma comprised 77.7% and invasive lobular carcinoma 22.22%. The 70-gene profile identified 21 cases (77.7%) as low-risk. Among those, 87.5% had a high-risk result with the 12-gene test, and 60% had a high-risk score with the 7-gene test. Conclusions: The findings support the utility observed in the sub-analysis of the NSABP-B42 study, showing that a low-risk result in the 70-genes signature, means high risk of late recurrence and the need for EET, emphasizing the importance of further evaluation and validation of genomic tests in predicting breast cancer recurrence risks. Larger sample sizes are necessary to confirm these results and establish their clinical relevance in oncology practice.