Can the eligibility criteria of the ACOSOG Z0011 trial be extended to patients undergoing mastectomy and presenting T3-T4 tumors? An analysis of non-sentinel axillary metastases

Purpose In the ACOSOG Z0011 trial, completing axillary lymph node dissection (cALND) did not benefit patients with T1-T2N0 early breast cancer (EBC) and 1-2 positive sentinel lymph nodes (SLN) undergoing breast-conserving surgery (BCT). This paper reports cALND rates in the clinical routine for patients who had higher (T3-T4) tumor stages and/or underwent mastectomy but otherwise met the ACOSOG Z0011 eligibility criteria. Aim of this study is to determine cALND time trends and non-sentinel metastases (NSM) rates in order to estimate occult axillary tumor burden.

Material/Methods Data were included from patients treated in 179 German breast cancer centers between 2008-2015. Time-trend rates were analyzed for cALND of patients with T3-T4 tumors separated for BCT and mastectomy and regarding presence of axillary macrometastases or micrometastases.

Results Data were available for 188,909 patients, of whom 19,009 were identified with 1-2 positive SLN. Those 19,009 patients were separated into 4 cohorts: (1) Patients with T1-T2 tumors receiving BCT (ACOSOG Z0011 eligible; n = 13,741), (2) T1-T2 with mastectomy (n = 4093), (3) T3-T4 with BCT (n = 269), (4) T3-T4 with mastectomy (n = 906). Among patients with T3-T4 tumors, cALND rates declined from 2008 to 2015: from 88.2 % to 62.6 % for patients receiving mastectomy and from 96.6 % to 58.1 % in patients receiving BCT. Overall rates for any NSM after cALND for cohorts 1-4 were 33.4 %, 42.3 %, 46.9 %, 58.8 % respectively.

Summary The cALND rates have decreased substantially in routine care in patients with ‘extended’ ACOSOG Z0011 eligibility criteria. Axillary tumor burden is higher in these patients than in the ACOSOG Z0011 trial.

Publication History

Article published online:
07 October 2020