Abstract P1-08-28: Real world use of OncotypeDx testing in the management of breast cancer. The North East England experience
Authors: Gault Abigail , Veeratterapillay Jayshree , Taylor Wendy 
Published: March 2022

Abstract
OncotypeDx testing is now routinely used to help decide management of hormone positive HER2 negative breast cancer. We have reviewed adjuvant treatment and long-term outcomes of breast cancer patients in those who had a genomic OncotypeDx study performed by the oncology team based at the Northern Centre for Cancer Care (NCCC) in Newcastle Upon Tyne over a 10 year period between 2011-2021. Guidance on the use of chemotherapy according to age and recurrence score changed from July 2018, which has been factored in to our review. We also reviewed the other clinicopathological features that could affect outcomes, including tumour size, grade, nodal status , Nottingham Prognostic index and the presence or absence of in situ disease and lymphovascular invasion. The notes of 908 patients who underwent a total of 974 oncotype Dx scores were reviewed to assess:1.Were the management decisions in line with the guidance on recurrence scores in use at that time?2.What were the outcomes for these patients (we have assessed disease free and overall survival for those who have completed 3 years or more of follow up)?3.For patients who relapsed, would a different decision have been made if current guidelines are applied?. 508 tumours had a low recurrence score (18 or less) and would typically be advised that chemotherapy would not be of benefit. 198 tumours scored in the intermediate group and a decision about chemotherapy currently would be made on the basis of their age. 268 tumours had a high recurrence score of 25 or greater and current advice would advocate chemotherapy in this group. The cut off figures for oncotype score groups have changed with previous ‘intermediate’ recurrence score figures from 18-30, and the ‘high’ score category above 30. 232 tumours of the 974 were node positive (80 with micrometastases, 148 with 1-3 nodes, and 4 had more than 4 involved nodes). In the 255 records evaluated thus far for patient outcome, only 22 relapses have occurred, with 9 local recurrences and 13 distant recurrences. Only two patients in the low recurrence score group evaluated so far (n=147) received chemotherapy and there were 6 patients with recurrences in this group; 4 were local and 3 distant. In the high recurrence score group (n=99 )85 patients received chemotherapy and 14 patients did not, of whom 5 were due to patient choice. Seven patients have so far relapsed (2 local & 5 distant recurrences). In the intermediate group 15 patients received chemotherapy of the total group evaluated to date(n=73). Six patients in the intermediate group have relapsed (2 local & 4 distant recurrences). Under modern guidelines, only two further patients in this group would have been offered chemotherapy. 25 of the patients in the intermediate group were 55 years or above and 4 of these received chemotherapy - under current UK guidance these patients would avoid chemotherapy. Whilst the aim is to share results from the complete dataset in our poster, early results from this study confirm the benefit of OncotypeDx testing in the real world management of patients with breast cancer. AcknowledgementsMark Verrill, NicCresti, Daniella Lee, Radha Todd, Helen Turnbull, Kathryn Wright, NajibahMahtab, Ed Hallam, Sarah Reynia
Citation Format: Abigail Gault, Jayshree Veeratterapillay, Wendy Taylor. Real world use of OncotypeDx testing in the management of breast cancer. The North East England experience [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P1-08-28.