Abstract P1-06-06: No age-related outcome disparities according to 21-gene recurrence score groups in early breast cancer patients treated by adjuvant chemotherapy in the prospective WSG PlanB trial

Background: Elderly breast cancer (BC) patients (pts) have been reported to have worse BC-related outcome than younger pts, even within clinical trials such as TEAM. Shak et al. recently showed in a large SEER data analysis that in the high 21-gene recurrence score (RS) group, older pts (>70y) receive less chemotherapy (CT) and have a worse BC-specific mortality than younger pts. Here, we therefore aimed to see whether there are age-related outcome disparities according to RS groups in pts receiving state-of-the-art CT in the prospective WSG PlanB trial. Material and Methods: PlanB compared 6 cycles of anthracycline-free TC vs. standard anthracycline-taxane based CT (4xECà4xDoc) in patients with high risk pN0 (T2-4, G2-3, Results: In all pts with luminal cancer and RS results (n=2577), there was an age-related significant difference in RS risk group assignment (p25; in pts 40-69 years, 18.3% had RS≤11, 61% RS 12-25, and 20.7%% RS>25; in elderly pts (>70y), 19.5% had RS≤11, 55.3% RS 12-25, and 25.2% RS>25. Among patients receiving chemotherapy, RS>25 vs. RS25, there were no significant differences in DFS between any two of these three age groups. Conclusion: A substantial percentage of elderly patients (> 70y) presents with high-risk luminal disease; these patients are candidates for CT. In PlanB, about 25% of elderly luminal BC patients had high-risk (RS>25) tumors. Nevertheless, after receiving modern adjuvant CT, their DFS was comparable to that of non-elderly pts with high-risk RS tumors. Consequently, older BC pts with high-risk luminal tumors who are fit enough to receive adjuvant CT should be treated according to guidelines in order to overcome age-dependent survival disparities which have been observed in registries for high-RS tumors. Citation Format: Harbeck N, Gluz O, Wuerstlein R, Clemens M, Malter W, Reimer T, Nuding B, Stefek A, Pollmanns A, Augustin D, Uleer C, Lorenz-Salehi F, Shak S, Chao C, Christgen M, Kates R, Kreipe H, Nitz U. No age-related outcome disparities according to 21-gene recurrence score groups in early breast cancer patients treated by adjuvant chemotherapy in the prospective WSG PlanB trial [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-06-06.