Retrospectively validating the results of the ACOSOG Z0011 trial in a large Asian Z0011-eligible cohort
Authors
Jiwoong Jung ; Wonshik Han ; Eun Sook Lee ; So-Youn Jung ; Jai Hong Han ; Dong-Young Noh ; Yumi Kim ; Hee Jun Choi ; Jeong Eon Lee ; Seok Jin Nam ; Jong Won Lee ; Hee Jeong Kim ; Eunhae Um ; Joo Heung Kim ; Seho Park ; Young Up Cho
Citation
BREAST CANCER RESEARCH AND TREATMENT, Vol.175(1) : 203-215, 2019
Axillary lymph node dissection ; Breast cancer ; Sentinel lymph node biopsy
Abstract
PURPOSE:
The Z0011 trial demonstrated that axillary dissection (ALND) could be omitted during breast-conserving therapy for cT1-2N0 breast cancers with 1-2 metastatic SLNs. However, that result has not been validated in a larger cohort and the significance of the small number of SLNs remains unclear. This study aimed to validate the Z0011 results within an Asian Z0011-eligible cohort and determine whether the number of sentinel lymph nodes (SLNs) influenced the Z0011-based outcomes.
METHODS:
Data from Asian patients who fulfilled the Z0011 criteria were collected from five hospitals. Disease recurrence (DR) was compared between patients who underwent ALND or SLN dissection (SLND) alone. Propensity-score matching was performed to reduce the effects of potential selection biases.
RESULTS:
During 2010-2016, 1750 Asian patients had 1-2 SLN metastases and fulfilled the Z0011 criteria. These patients included 707 cases treated using SLND alone (40%) and 967 patients with ≤ 2 SLNs (55%). Ninety-five patients (5.4%) experienced DR at a median interval of 50 months, although the rates of DR were similar in the ALND and SLND groups. The adjusted hazard ratios for DR after ALND omission were 0.95 (95% CI 0.55-1.64) among the entire cohort and 0.83 (95% CI 0.34-2.03) among patients with ≤ 2 SLNs.
CONCLUSIONS:
In this Asian Z0011-eligible cohort, ALND omission did not increase risk of DR, even among patients with ≤ 2 SLNs. Therefore, the Z0011 strategy might be safely applied in Asia, and a small number of SLNs did not significantly influence this strategy.