Introduction: Decisions regarding adjuvant chemotherapy in women with oestrogen receptor positive, human epidermal growth factor receptor 2 negative, node negative, early invasive breast cancer are unclear. The Recurrence Score® (RS) from Oncotype DX® (ODX) testing guides decisions based on individual cancer genomics. The aim of this study was to evaluate the impact of introducing ODX results on adjuvant treatment decisions and its potential economic benefits.
Methods: Patients offered the test were identified from the ODX requesting system. Information on reasons behind chemotherapy treatment decisions were collected from clinical letters and the pathology system. The Nottingham prognostic index (NPI) scores were calculated for each individual patient.
Results: A total of 101 patients were identified as having undergone ODX testing over 21 months. The median age was 57 years (range: 41-72 years), the median NPI was 3.70 (range: 3.40-5.26) and the median RS was 17 (range: 0-59). NPI did not predict the risk category. All of the patients in the high risk group, 35.1% in the intermediate risk group and 5.4% in the low risk group received chemotherapy. The majority of low risk patients who received chemotherapy made a decision prior to the ODX result.
Conclusions: In our unit, RS aided our decision making regarding adjuvant chemotherapy. Patients with a higher RS were more likely to receive chemotherapy. If NPI had been used alone, more women would have been offered chemotherapy. Good communication with patients prior to testing is important to ensure it is cost effective.
Keywords: Adjuvant chemotherapy; Breast neoplasms; Gene expression profiling; Genomics; Molecular diagnostic techniques.