Comparison of multiple oncotype DX^® from the same patient

Area of Science:

• Oncology
• Genomics
• Breast Cancer Research

Background:

• The Oncotype DX Recurrence Score (RS) is a genomic test used to predict the likelihood of breast cancer recurrence.
• Evaluating concordance of multiple RS in patients with multiple tumors or recurrence is crucial for treatment decisions.
• Current NCCN guidelines' recommendations for managing multiple RS have not been extensively evaluated.

Purpose of the Study:

• To assess the concordance of multiple Oncotype DX Recurrence Scores (RS) in breast cancer patients.
• To evaluate RS concordance based on tumor characteristics and location according to NCCN guidelines.
• To determine if multiple RS results can be used to omit further Oncotype DX testing for individual tumors.

Main Methods:

• Retrospective review of breast cancer patients with two or more Oncotype DX RS results.
• Stratification of RS by tumor type, including same tumor, ipsilateral, contralateral, and in-breast recurrence.
• Comparison of RS concordance rates based on tumor characteristics and NCCN guidelines.

Main Results:

• Twenty-four patients with multiple RS were analyzed.
• RS concordance varied significantly by tumor type: 100% for the same tumor, 91.7% for multiple ipsilateral tumors, 71.4% for contralateral tumors, and 66.7% for in-breast recurrent tumors.
• Concordance rates suggest potential discordance when multiple RS assays are performed for the same patient.

Conclusions:

• Oncotype DX RS concordance is not consistently high across different tumor scenarios in breast cancer patients.
• The variability in concordance highlights the need for careful interpretation of multiple RS results.
• Current concordance levels do not support omitting Oncotype DX testing for each individual tumor in patients with multiple assays.