Top Line: Does Oncotype DX predict local recurrence risk in older, lower risk breast cancer patients who omit adjuvant radiation?
The Study: Oncotype DX was designed to predict the risk of distant metastasis and potential benefit of adjuvant chemotherapy for hormone receptor positive breast cancer. Two large studies (NSABP B14 and B20; MSKCC study) have shown that the Oncotype score is significantly associated with locoregional recurrence. This study asks whether Oncotype predicts recurrence risk specifically in a population of older patients who are eligible to omit adjuvant radiation. The cohort included over 1500 patients age 65 and older with early stage, T1, ER/PR+, HER2- breast cancer who had breast conservation surgery. The majority (92%) had a low risk score (≤25). While most receive adjuvant RT, the rate was lower for those with a low score (77% v 86%). A high score was significantly associated with other high risk features including LVI, high grade disease, and younger age. At 6 years, there was no significant difference in the cumulative rates of local recurrence between low and high risk scores (1.9% v 0.76%). As expected, overall risk of local recurrence was higher when RT was omitted (4.3% v 1.1% at 6 years), the Oncotype score (as both a continuous and categorical variable) was not associated with local recurrence risk.
TBL: In this cohort of patients 65 and older with early stage, ER/PR+ breast cancer, Oncotype DX score (low or high) was not a strong predictor of local recurrence risk. | Rosenzweig, Int J Radiat Oncol Biol Phys 2026
The Study: Oncotype DX was designed to predict the risk of distant metastasis and potential benefit of adjuvant chemotherapy for hormone receptor positive breast cancer. Two large studies (NSABP B14 and B20; MSKCC study) have shown that the Oncotype score is significantly associated with locoregional recurrence. This study asks whether Oncotype predicts recurrence risk specifically in a population of older patients who are eligible to omit adjuvant radiation. The cohort included over 1500 patients age 65 and older with early stage, T1, ER/PR+, HER2- breast cancer who had breast conservation surgery. The majority (92%) had a low risk score (≤25). While most receive adjuvant RT, the rate was lower for those with a low score (77% v 86%). A high score was significantly associated with other high risk features including LVI, high grade disease, and younger age. At 6 years, there was no significant difference in the cumulative rates of local recurrence between low and high risk scores (1.9% v 0.76%). As expected, overall risk of local recurrence was higher when RT was omitted (4.3% v 1.1% at 6 years), the Oncotype score (as both a continuous and categorical variable) was not associated with local recurrence risk.
TBL: In this cohort of patients 65 and older with early stage, ER/PR+ breast cancer, Oncotype DX score (low or high) was not a strong predictor of local recurrence risk. | Rosenzweig, Int J Radiat Oncol Biol Phys 2026