AUTHOR=Lu Yujie , Tong Yiwei , Huang Jiahui , Lin Lin , Wu Jiayi , Fei Xiaochun , Huang Ou , He Jianrong , Zhu Li , Chen Weiguo , Li Yafen , Chen Xiaosong , Shen Kunwei 

TITLE=Primary 21-Gene Recurrence Score and Disease Outcome in Loco-Regional and Distant Recurrent Breast Cancer Patients

JOURNAL=Frontiers in Oncology

VOLUME=10

YEAR=2020

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2020.01315

DOI=10.3389/fonc.2020.01315

ISSN=2234-943X

ABSTRACT=<p><bold>Background:</bold> The 21-gene recurrence score (RS) assay has been proven prognostic and predictive for hormone receptor-positive/HER2-negative, node-negative early breast cancer patients. However, whether primary 21-gene RS can predict prognosis in recurrent breast cancer patients remained unknown.</p><p><bold>Patients and Methods:</bold> Consecutive breast cancer patients operated in Comprehensive Breast Health Center, Shanghai Ruijin Hospital between January 2009 and December 2018 were retrospectively analyzed. Patients with available 21-gene RS result for the primary tumor and reporting disease recurrence during follow-up were included. Association of 21-gene RS and overall survival (OS), post-recurrence overall survival (PR-OS), post-recurrence progression-free survival (PR-PFS), and first-line systemic treatment after recurrence were compared among different groups.</p><p><bold>Results:</bold> A total of 74 recurrent patients were included, with 10, 27, 37 patients in the RS &lt;18, 18–30, and ≥ 31 groups, respectively. Recurrent patients with RS ≥ 31 were more likely to receive chemotherapy as their first-line treatment compared to those with RS &lt;31 (<italic>P</italic> = 0.025). Compared to those with RS &lt;31, patients with RS ≥ 31 had significantly worse OS (<italic>P</italic> = 0.025), worse PR-OS (<italic>P</italic> = 0.026), and a trend of inferior PR-PFS (<italic>P</italic> = 0.106). Multivariate analysis demonstrated that primary ER expression level (OS: <italic>P</italic> = 0.009; PR-OS: <italic>P</italic> = 0.017) and histological grade (OS: <italic>P</italic> = 0.003; PR-OS: <italic>P</italic> = 0.009), but not primary 21-gene RS (OS: <italic>P</italic> = 0.706; PR-OS: <italic>P</italic> = 0.120), were independently associated with worse OS and PR-OS.</p><p><bold>Conclusions:</bold> High primary 21-gene RS tended to be associated with worse disease outcome in loco-regional and distant recurrent breast cancer patients, which could influence the first-line systemic treatment after relapse, warranting further clinical evaluation.</p>