TY - JOUR

T1 - Benefit of adjuvant chemotherapy and trastuzumab in patients with HER2-positive, node-negative breast tumors ≤ 10 mm

T2 - a nationwide study

AU - Hassing, Christina M.S.

AU - Mejdahl, Mathias Kvist

AU - Lænkholm, Anne Vibeke

AU - Kroman, Niels

AU - Knoop, Ann Søegaard

AU - Tvedskov, Tove Holst Filtenborg

N1 - Funding Information: This study is part of a PhD-project supported by the Danish Cancer Society, Denmark (R246-A14574-19-S73); Interne Forskningsmidler, Herlev and Gentofte Hospital, Denmark; Tømrermester Jørgen Holm og Hustru Elisa F. Hansens Mindelegat, Denmark (20006-1846); Dansk Kræftforskningsfond, Denmark; Region Sjællands Sundhedsvidenskabelige Forskningsfond, Denmark (R19A283B198); Dansk Brystkirurgisk Selskabs legat, Denmark; Helsefonden, Denmark (20-B-0003). The funding sources had no role in the study design; in the collection, analysis and interpretation of data; in the writing of the report; or in the decision to submit the article for publication. Funding Information: Ann Søegaard Knoop reports personal fees from Novartis, Roche, Merck, Daiichi Sankyo, Gilead Sciences, Pfizer, Eli Lilly. Furthermore, she has been national or site investigator for Daiichi Sankyo and Sanofi. Tove Tvedskov reports speaker honorariums from Roche, MSD and Pfizer. Anne-Vibeke Lænkholm reports institutional research grants from Novartis and Astra Zeneca (AZ). Anne-Vibeke Lænkholm reports personal fees for participation in advisory boards, Novartis and AZ and for a research collaboration with Veracyte. No other potential conflicts of interest were reported.

PY - 2022

Y1 - 2022

N2 - Purpose: The purpose of this study was to evaluate the effect of chemotherapy and trastuzumab on invasive disease-free survival (iDFS) and overall survival (OS) in patients with human epidermal growth factor receptor 2 (HER2) positive, T1abN0 breast cancer. Methods: In the Danish Breast Cancer Group database, patients with HER2-positive, T1abN0 tumors diagnosed between 2007 and 2016 were identified. Cox proportional hazards analysis was performed to analyze the association between adjuvant chemotherapy and trastuzumab and iDFS and OS. Results: Of 605 patients included in the analyses, 465 patients received chemotherapy and trastuzumab and 140 patients did not. Chemotherapy and trastuzumab did not improve iDFS or OS significantly in adjusted analyses. 5-year iDFS was 92.3% vs. 89.9%, Hazard ratio (HR) 1.01 (p = 0.98), and 5-year OS was 97.4% vs. 94.3%, HR 0.60 (p = 0.15), chemotherapy and trastuzumab vs. no chemotherapy/trastuzumab. In unadjusted analyses, significant treatment benefit on OS was found in patients with T1b tumors. The largest absolute treatment benefits were found in patients with T1b tumors and estrogen receptor (ER) negative tumors, respectively, whereas treatment effects in patients with T1a tumors and ER-positive tumors, respectively, were limited. Conclusion: Adjuvant chemotherapy and trastuzumab did not improve OS or iDFS significantly in patients with HER2-positive, T1abN0 breast cancers in adjusted analyses. In unadjusted analyses, significant OS benefit was found in patients with T1b tumors. The largest absolute benefit was observed in patients with T1b tumors and ER-negative tumors, respectively, whereas the effect was limited in patients with T1a tumors and ER-positive tumors, respectively.

AB - Purpose: The purpose of this study was to evaluate the effect of chemotherapy and trastuzumab on invasive disease-free survival (iDFS) and overall survival (OS) in patients with human epidermal growth factor receptor 2 (HER2) positive, T1abN0 breast cancer. Methods: In the Danish Breast Cancer Group database, patients with HER2-positive, T1abN0 tumors diagnosed between 2007 and 2016 were identified. Cox proportional hazards analysis was performed to analyze the association between adjuvant chemotherapy and trastuzumab and iDFS and OS. Results: Of 605 patients included in the analyses, 465 patients received chemotherapy and trastuzumab and 140 patients did not. Chemotherapy and trastuzumab did not improve iDFS or OS significantly in adjusted analyses. 5-year iDFS was 92.3% vs. 89.9%, Hazard ratio (HR) 1.01 (p = 0.98), and 5-year OS was 97.4% vs. 94.3%, HR 0.60 (p = 0.15), chemotherapy and trastuzumab vs. no chemotherapy/trastuzumab. In unadjusted analyses, significant treatment benefit on OS was found in patients with T1b tumors. The largest absolute treatment benefits were found in patients with T1b tumors and estrogen receptor (ER) negative tumors, respectively, whereas treatment effects in patients with T1a tumors and ER-positive tumors, respectively, were limited. Conclusion: Adjuvant chemotherapy and trastuzumab did not improve OS or iDFS significantly in patients with HER2-positive, T1abN0 breast cancers in adjusted analyses. In unadjusted analyses, significant OS benefit was found in patients with T1b tumors. The largest absolute benefit was observed in patients with T1b tumors and ER-negative tumors, respectively, whereas the effect was limited in patients with T1a tumors and ER-positive tumors, respectively.

KW - Breast cancer

KW - Human epidermal growth factor receptor 2 (HER2)

KW - T1abN0

KW - Trastuzumab

U2 - 10.1007/s10549-022-06724-y

DO - 10.1007/s10549-022-06724-y

M3 - Journal article

C2 - 36076126

AN - SCOPUS:85137571893

VL - 196

SP - 197

EP - 206

JO - Breast Cancer Research and Treatment

JF - Breast Cancer Research and Treatment

SN - 0167-6806

IS - 1

ER -