Abstract P5-15-07: Knowledge of oncotype Dx recurrence score increases confidence and concordance in adjuvant decisions of U.K. oncologists

Introduction The addition of Oncotype Dx Recurrence Score (RS) to the assessment of patients with ER positive, HER2 negative, node negative breast cancer has led to a reduction in the use of adjuvant chemotherapy. However, crude measurement of this reduction masks a more complex scenario. Prior to the introduction of routine Oncotype DX testing by NHS England, we wished to explore in more detail the potential impact of the knowledge of the RS on the therapeutic discussion. This study analyses the impact of RS on the adjuvant therapy recommendations within a UK Cancer Centre. In particular, it examines how the degree of certainty the oncologist has about the best option changes with knowledge of RS and how this influences concordance of decision making between oncologists. Methods A panel of five breast oncologists reviewed 50 consecutive cases, collected from November 2012 until November 2014, across two hospitals. Oncologists allocated each case to one of four treatment categories: chemotherapy recommended (CRec), chemotherapy discussed with a bias towards recommended (CDis), chemotherapy discussed with a bias toward endocrine therapy alone (EDis) or endocrine therapy only advised (ERec). The cases were analysed blindly and in random order without and with RS . The degree to which knowledge of RS altered treatment recommendation was analyzed. Other outcomes included the proportion of patients who were scored ERec compared with any other outcome, the trend towards definitive recommendations, the impact of RS on concordant decision making and the degree to which outcome was stratified by RS result. Chi squared and Spearman9s coefficient statistical tests were used in analysis. Results Knowledge of the RS altered the recommended treatment category in 66.7% of cases (p Overall, RS correlated significantly with treatment recommendation. Oncologists were confident to recommend endocrine therapy alone in 46% of patients when RS was known compared with only 6% of patients without RS. Complete concordance between oncologists increased with the knowledge of RS from 14% to 64%. Conclusion Discussion of adjuvant chemotherapy with patients who have ER positive, HER2 negative, node negative breast cancer can be complex and, at times, confusing for the patient, leading to increased distress. This study shows that, in addition to the previously recognised reduction in overall use of chemotherapy, the knowledge of the RS increased the proportion of patients for whom the oncologist felt confident in making a firm treatment recommendation. An added benefit was to increase concordance between different oncologists compared to that achieved when relying on standard pathological features. Citation Format: Kiernan T, Olsson-Brown AC, Innes H, Holcombe C, Thorp N, O9Hagan J, Wong H, Palmieri C, O9Reilly S. Knowledge of oncotype Dx recurrence score increases confidence and concordance in adjuvant decisions of U.K. oncologists. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-15-07.