The applicability of the ACOSOG Z0011 Criteria to breast cancer patients in Hong Kong

Abstract

Background: The ACOSOG Z0011 trial demonstrated safe omission of axillary lymph node dissection (ALND) in patients with one or two positive sentinel lymph nodes (SLNs) receiving breast conservative surgery, followed by whole breast irradiation and adjuvant systemic treatment. This study aims to evaluate the exportability of the ACOSOG Z0011 criteria in an Asian/Chinese cohort residing in Hong Kong.

Methods: Retrospective analysis of a prospectively maintained database in a University affiliated tertiary breast centre was performed from June 2014 to May 2019. All breast cancer patients with no palpable adenopathy before surgery, one or more positive sentinel lymph nodes on histological examination and no prior neoadjuvant systemic treatment were recruited. Patients were grouped as eligible or ineligible according to the ACOSOG Z0011 criteria. The eligible group was compared with the sentinel alone group in the ACOSOG Z0011 cohort.

Results: Two hundred and forty-eight patients were recruited into the study. Sixty patients (24%) met the ACOSOG Z0011 criteria and could potentially avoid ALND. A higher percentage of clinical T2 tumors were observed in our eligible group than in the ACOSOG Z0011 trial (P=0.002). The histological subtype, tumor grade, estrogen receptor (ER)/progestogen receptor (PR) status and lymphovascular invasion status did not differ. There was no statistically significant difference in the proportion of SLN micrometastasis and macrometastasis between the two groups.

Conclusions: This study demonstrated clinical similarities between our eligible cohort and the ACOSOG Z0011 cohort, which confirms exportability of the ACOSOG Z0011 criteria to a subset of population in Hong Kong.

Keywords: Breast cancer; biopsy; lymph node dissection; sentinel lymph node (SLN).