Long-Term Survival Outcomes and Risk Factors for Axillary and Locoregional Recurrence in Japanese Patients with Sentinel Node-Positive Breast Cancer Treated in Accordance with the ACOSOG Z0011 Strategy

Yuri Oyama; Nobuyoshi Kittaka; Ayako Higuchi; Yusa Togashi; Azusa Taniguchi; Yukiko Seto; Ai Soma; Sungae Park; Jun Okuno; Noriyuki Watanabe; Saki Matsui; Mikiya Ishihara; Minako Nishio; Keiichiro Honma; Takahiro Nakayama

doi:10.1159/000540363

Long-Term Survival Outcomes and Risk Factors for Axillary and Locoregional Recurrence in Japanese Patients with Sentinel Node-Positive Breast Cancer Treated in Accordance with the ACOSOG Z0011 Strategy

Oncology. 2024 Aug 19:1-13. doi: 10.1159/000540363. Online ahead of print.

Authors

Affiliations

¹ Department of Breast and Endocrine Surgery, Osaka International Cancer Institute, Osaka, Japan.
² Department of Breast Surgery, Osaka Rosai Hospital, Osaka, Japan.
³ Department of Medical Oncology, Osaka International Cancer Institute, Osaka, Japan.
⁴ Department of Diagnostic Pathology and Cytology, Osaka International Cancer Institute, Osaka, Japan.

PMID: 39159619
DOI: 10.1159/000540363

Abstract

Introduction: In 2018, we reported the results of a study to assess the feasibility of applying the ACOSOG Z0011 criteria to Japanese patients with early-stage breast cancer (median follow-up, 3 years). Their results over the longer term can now be presented. Risk factors for axillary and locoregional recurrence in Z0011-eligible patients are unknown.

Methods: Long-term survival outcomes were investigated by analyzing data from patients enrolled in the feasibility study. Data from the feasibility study patients, and from patients eligible for the Z0011 strategy after its introduction into clinical practice, were subjected to multivariate logistic regression analysis to identify risk factors for axillary and locoregional recurrence.

Results: Regarding long-term outcomes for the feasibility study patients (n = 189), distant disease-free survival rates at 5 and 7 years were 90.4 ± 2.1% and 85.9 ± 2.6%, respectively, and overall survival rates at 5 and 7 years were 97.3 ± 1.2% and 95.3 ± 1.7%, respectively. Analysis of data from these patients plus the 93 who received Z0011 in clinical practice (total, n = 282) identified the following independent risk factors for axillary recurrence: absence of high axillary tangential irradiation (OR, 5.87 [95% CI, 1.09-31.35], p = 0.04) and number of positive sentinel lymph nodes (OR, 4.65 [95% CI, 1.11-19.48], p = 0.04). Only high Ki67 labeling index (OR, 5.92 [95% CI, 1.31-26.70], p = 0.02) was identified as an independent risk factor for locoregional recurrence.

Conclusion: Long-term survival outcome results of the feasibility study show that the Z0011 strategy can be used to treat Japanese patients with early-stage breast cancer. Our findings regarding risk factors suggest that high axillary tangent irradiation is necessary for the prevention of axillary recurrence and that irradiation, including of the regional lymph nodes, should be considered, especially in patients with high Ki67 index values.

Keywords: Axillary recurrence; Breast cancer; Locoregional recurrence; Long-term outcomes; Risk factors; Z0011.