Effect of neoadjuvant versus adjuvant chemotherapy on ipsilateral breast tumor recurrence after breast-conserving surgery and whole-breast irradiation.

Authors

null

Jong-Ho Cheun

Seoul Metropolitan Government Seoul National University Boramae Medical Center, Seoul, South Korea

Jong-Ho Cheun , Hong-Kyu Kim , Han-Byoel Lee , Hyeong-Gon Moon , Wonshik Han

Organizations

Seoul Metropolitan Government Seoul National University Boramae Medical Center, Seoul, South Korea, Seoul National University Hospital, Seoul, South Korea, Department of Surgery, Seoul National University College of Medicine, Seoul, South Korea, Department of Surgery and Cancer Research Institute, Seoul National University, College of Medicine, Seoul, South Korea

Research Funding

No funding received

Background: Early Breast Cancer Trialists’ Collaborative Group conducted a large meta-analysis and reported that patients who underwent neoadjuvant chemotherapy (NAC) had higher ipsilateral breast tumor recurrence (IBTR) rate than those with adjuvant chemotherapy. However, since the study was conducted with patients treated two decades ago, the results could not reflect the advance in treatments and IBTR rate was much higher than in recent studies, Thus, we investigated the association between chemotherapy settings and IBTR rates in breast cancer patients. Methods: We retrospectively reviewed the data of 5,307 patients who underwent breast conserving surgery followed by whole breast irradiation between January 2004 and December 2018 in a single institution. Patients who underwent mastectomy or omitted chemotherapy were excluded. Results: The 1,473 patients who underwent NAC showed significantly higher IBTR rate than the 3,564 patients who underwent adjuvant chemotherapy (10-year risk: 4.5% vs. 4.0%; log-rank p=0.045, hazard ratio 1.42 [95%CI,1.01-1.99]). The difference was more evident for patients with hormone receptor (HR) positive and human epidermal growth factor receptor-2 (HER2) negative tumor (unadjusted p=0.001, hazard ratio 2.27 [95%CI,1.37-3.74; adjusted p=0.002, hazard ratio 2.80 [95%CI,1.45-5.42]], and the statistical significance was still remained after 1:1 propensity score matching (p=0.026). In contrast, patients with other subtypes did not show significant differences between two groups. Conclusions: Patients who underwent NAC for HR+/HER2- tumors carry increased risk of IBTR than those who underwent adjuvant chemotherapy. Our observation supports the need for considering tumor subtypes in initial treatment. In addition, more intensive surveillance would be needed for patients with HR+/HER2- tumors after NAC.

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Abstract Details

Meeting

2022 ASCO Annual Meeting

Session Type

Poster Session

Session Title

Breast Cancer—Local/Regional/Adjuvant

Track

Breast Cancer

Sub Track

Neoadjuvant Therapy

Citation

J Clin Oncol 40, 2022 (suppl 16; abstr 604)

DOI

10.1200/JCO.2022.40.16_suppl.604

Abstract #

604

Poster Bd #

375

Abstract Disclosures