Adjuvant chemotherapy is associated with an overall survival benefit regardless of age in ER+/HER2- breast cancer pts with 1-3 positive nodes and oncotype DX recurrence score 20 to 25: an NCDB analysis

Nickolas Stabellini; Lifen Cao; Christopher W Towe; Xun Luo; Amanda L Amin; Alberto J Montero

doi:10.3389/fonc.2023.1115208

Adjuvant chemotherapy is associated with an overall survival benefit regardless of age in ER+/HER2- breast cancer pts with 1-3 positive nodes and oncotype DX recurrence score 20 to 25: an NCDB analysis

Front Oncol. 2023 Apr 24:13:1115208. doi: 10.3389/fonc.2023.1115208. eCollection 2023.

Authors

Nickolas Stabellini^{1

2

3}, Lifen Cao³, Christopher W Towe^{1

4

5}, Xun Luo^{1

4

5}, Amanda L Amin^{1

5

6}, Alberto J Montero^{1

3}

Affiliations

¹ Case Western Reserve University School of Medicine, Case Western Reserve University, Cleveland, OH, United States.
² Faculdade Israelita de Ciências da Saúde Albert Einstein, Hospital Israelita Albert Einstein, São Paulo, Brazil.
³ Division of Hematology and Oncology, Department of Medicine, University Hospitals Seidman Cancer Center, University Hospitals Cleveland Medical Center, Cleveland, OH, United States.
⁴ Division of Thoracic and Esophageal Surgery, Department of Surgery, University Hospitals Cleveland Medical Center, Cleveland, OH, United States.
⁵ University Hospitals Research in Surgical Outcomes and Effectiveness (UH-RISES), University Hospitals Cleveland Medical Center, Cleveland, OH, United States.
⁶ Division of Surgical Oncology, Department of Surgery, University Hospitals Seidman Cancer Center, University Hospitals Cleveland Medical Center, Cleveland, OH, United States.

Abstract

Background: The RxPONDER trial found that among breast cancer patients with estrogen receptor positive (ER+) breast cancer, 1-3 positive axillary nodes, and a recurrence score of ≤25, only pre-menopausal women benefitted from adjuvant chemoendocrine therapy; postmenopausal women with similar characteristic did not benefit from adjuvant chemotherapy. We aimed to replicate the RxPonder trial using a larger patient cohort with real world data to determine whether a RS threshold existed where adjuvant chemotherapy was beneficial regardless of age.

Methods: The National Cancer Database (NCDB) was queried for women with ER+, human epidermal growth factor receptor 2 (HER2) negative breast cancer, 1-3 positive axillary nodes, and RS ≤25 who received endocrine (ET) only or chemo-endocrine therapy (CET). Cox regression interaction was explored between CET and age as a surrogate for menopausal status.

Results: The final analytic cohort included 28,427 eligible women: 7,487 (26.3%) received adjuvant CET and 20,940 (73.7%) ET. In the entire cohort, RS had a normal distribution, with a median score of 14. After correcting for demographic and clinical variables, a threshold effect was observed with RS >20 being associated with a significantly inferior overall survival (OS) (P value range: < 0.001-0.019). In women with RS of 20-25, CET was associated with a significant improvement in OS compared to ET alone, regardless of age (age <=50: HR = 0.334, P=0.002; age>50: HR=0.521, P=0.019).

Conclusion: Among women with ER+/HER2- breast cancer with 1-3 positive nodes, and a RS of 20-25-in contrast to the RxPONDER trial-we observed that CET was associated with an OS benefit in women regardless of age.

Keywords: ER+ breast cancer; HER2- breast cancer; adjuvant (chemo)radiotherapy; breast cancer; chemotherapy; oncotype; survival.

Grants and funding

NS is supported through funding from the Sociedade Beneficente Israelita Brasileira Albert Einstein on the program “Marcos Lottenberg and Marcos Wolosker International Fellowship for Physicians Scientist - Case Western”.