The use of Oncotype Dx in adjuvant chemotherapy decision-making in early breast cancer patients with intermediate risk of mortality at 10 years
Session type: Poster / e-Poster / Silent Theatre session
Validated genomic tests such as Oncotype Dx are being used internationally to quantify risk and potential benefit from chemotherapy, particularly in the intermediate risk group.
We retrospectively analysed data on patients diagnosed with breast cancer between 1/04/2014 and 31/03/2015, who underwent curative local breast +/- axillary surgery. Patients included were those suitable for Oncotype Dx under NICE recommendations with regards to grade, size, nodal involvement and receptor status. Intermediate risk was defined as an absolute overall survival benefit with chemotherapy between 3-5% at 10 years using the Adjuvant! Online or PREDICT tools.
From 1/04/2015 to 31/03/2016, Oncotype Dx was offered to all patients with an intermediate risk: benefit as defined above. The recurrence score results were used to guide the treatment decisions, with scores above 25 being encouraged to consider chemotherapy. Treatment decisions were compared between the two sets of patients.
31 patients were included in the retrospective group. 31 patients were included in the prospective group and were offered Oncotype Dx.
In the retrospective group, 11/31 patients (35%) received adjuvant chemotherapy compared to 7/31 patients (23%) in the prospective group. There were similar numbers of grade 3 tumours in both groups, however of those who received chemotherapy, 70% of patients had Grade 3 tumours in the retrospective group compared to 43% in the prospective group.
Oncotype Dx scores were associated with less chemotherapy use and may have given more confidence to decline chemotherapy in the patients with grade 3 tumours. Oncotype Dx testing may prevent over treatment but, in our centre, the clinician/ patient decisions using non-genomic evaluation are not dissimilar to that following genomic testing. This data was part of the English CQUIN–(Commissioning for Quality and Innovation) project and cost–effectiveness evaluation of Oncotype from this project is awaited.