68 - NATIONAL CANCER DATABASE SHOWS AA BREAST CANCER PATIENTS HAVE PROPORTIONATELY HIGHER RECURRENCE SCORES AFTER TAILORX RECLASSIFICATION VS CA PATIENTS: RACIAL CONSIDERATIONS IN RS INTERPRETATION

Objectives: The recurrence score (RS) is used in early stage, hormone positive breast cancers (BC), to predict the benefit of adjuvant chemotherapy. The original RS divided patients into three risk categories that determined clinical decisions. The RS was developed using a primarily Caucasian population with little racial variability. The TAILORx study further stratified the RS into either “low or high risk” categories and allowed ~60% of women with early-stage breast cancer to omit chemotherapy. The primary aim of this study was to determine if there was a difference in risk re-classification pre-TAILORx and post-TAILORx between African American (AA) and Caucasian (CA) patients. A secondary aim was to determine if AA and CA women were equally able to omit chemotherapy.

Methods: AA and CA patients with BC who underwent RS testing in the NCDB from 2004 to 2014 were included. RS was defined as: “pre-TAILORx” scores, classified into low (0-17), intermediate (18-30), and high risk (> 30) groups; and “post-TAILORx” scores, classified into low (0-25) and high risk (> 25) groups.

Results: 80,532 women were included; 87.7% were CA and 7.3% were AA; 87.5% (n = 61,815) CA and 82.6% (n = 4,824) AA were reclassified with low RS using post-TAILORx scores. 12.5% (n = 8,820) CA and 17.4% (n = 1,015) AA patients were reclassified with a high RS using post-TAILORx scores. In the pre-menopausal cohort, the percentage of CA patients that were reclassified as having low RS went from 60% to 74%, while AA patients went from 49% to 63%. In the pre-menopausal high RS cohort, the percentage of CA patients reclassified as having a high RS increased from 7% to 13%, while AA increased from 14% to 23%. Post-menopausal patients with a low RS increased from 60% to 86% in CA patients and from 56% to 81% in AA patients. Post-menopausal patients with high RS increased from 8% to 14% in CA patients and from 11% to 19% in AA patients.

Conclusion: Reclassification after TAILORx has most patients with early stage, hormone positive breast cancers omit chemotherapy. However, a proportionately lower number of AA patients can safely omit chemotherapy when compared to Caucasian patients with similar tumor characteristics and clinical risk after reclassification of the RS using new TAILORx scoring, especially in the pre-menopausal AA cohort. Given that the RS was developed in a homogenous CA population, validity in other racial/ethnic groups may not be as robust and may impact treatment decisions.