Effect of the American College of Surgeons Oncology Group Z0011 trial on axillary management in breast cancer patients in the Australian setting

Population-Level Impact of Omitting Axillary Lymph Node Dissection in Early Breast Cancer Women: Evidence from an Economic Evaluation in Germany

BACKGROUND

The American College of Surgeons Oncology Group Z0011 trial showed that complete axillary lymph node dissection (cALND) did not improve survival benefits in patients with one or two tumour-involved sentinel lymph nodes and undergoing breast conservation. Still, a considerable number of the Z0011-eligible patients continue to be treated with cALND in various countries. Given the potential economic gain from implementation of the Z0011 recommendations, we quantified population-level impacts of omitting cALND among Z0011-eligible patients in clinical practice.

METHODS

This 2-year economic analysis adopted both the perspective of patients under statutory insurance and the societal perspective, using data collected prospectively from 179 German breast cancer units between 2008 and 2015. The estimation of cost savings and health gain relied on a single decision tree, which considered three scenarios: clinical practice at the baseline; actual implementation in routine care; and hypothetical full implementation in all eligible patients.

RESULTS

Data for 188,909 patients with primary breast cancer were available, 13,741 (7.3%) of whom met the Z0011 inclusion criteria. The use of cALND decreased from 94.3% in 2010 to 46.9% in 2015, resulting in a gain of 335 quality-adjusted life-years and a saving of EUR50,334,756 for the society. Had cALND been omitted in all eligible patients, the total gain would have been more than double.

CONCLUSIONS

The implementation of the Z0011 recommendations resulted in substantial savings and health gain in Germany. Our findings suggest that it is beneficial to introduce additional policy measures to promote further uptake of the Z0011 recommendations in clinical practice.

The role of pre-operative axillary ultrasound in assessment of axillary tumor burden in breast cancer patients: a systematic review and meta-analysis

BACKGROUND

Recent studies have suggested that a significant proportion of patients with axillary nodal metastases diagnosed by pre-operative axillary ultrasound (AUS)-guided needle biopsy were over-treated with axillary lymph node dissection (ALND). The role of routine AUS and needle biopsy in early breast cancer was questioned. This review aims to determine if pre-operative AUS could predict the extent of axillary tumor burden and need of ALND.

METHODS

PubMed and Embase literature databases were searched systematically for abnormal AUS characteristics and axillary nodal burden. Studies were eligible if they correlated the sonographic abnormalities in AUS with the resultant axillary nodal burden in ALND according to the ACOSOG Z0011 criteria.

RESULTS

Eleven retrospective studies and one prospective study with 1658 patients were included. Sixty-five percent of patients with one abnormal lymph node in AUS and 56% of those with two had low axillary nodal burden. Using one abnormal lymph node as the cut-off, the pooled sensitivity and specificity in prediction of axillary nodal burden were 66% (95%CI 63-69%) and 73% (95% CI 70-76%), respectively. Across the six studies that evaluated suspicious nodal characteristics, increased nodal cortical thickness may be associated with high axillary nodal burden.

CONCLUSION

More than half of the patients with pre-operative positive AUS and biopsy proven axillary nodal metastases were over-treated by ALND. Quantification of suspicious nodes and extent of cortical morphological changes in AUS may help identify suitable patients for sentinel lymph node biopsy.

Effect of non-sentinel metastasis on adjuvant treatment decisions and survival in Z0011 eligible non-screened detected breast cancer population

BACKGROUND

The Z0011 trial results have shown that axillary lymph node dissection (ALND) can be avoided in cT1-2 patients undergoing breast conservation surgery with 1-2 metastatic sentinel lymph nodes (SLNs). We compared the clinicopathological characteristics of the Z0011 eligible non-screen detected breast cancer patients' cohort with the Z0011 trial study population. Additionally, we have explored the effect of non-sentinel metastasis on adjuvant treatment decisions and survival.

METHODS

The details of early breast cancer (EBC) patients fulfilling Z0011 eligibility criteria were retrieved from a prospectively maintained database (2013-2017) and electronic medical records. We used Statistical Package for the Social Sciences 25 and Stata V15 for the data analysis.

RESULTS

128/194 (66%) sentinel lymph node biopsy positive patients had fulfilled the Z0011 inclusion criteria. Compared to the Z0011 study, our cohort patients were younger, with more aggressive disease (higher T2, Grade 3), had a higher rate of macrometastasis (82.8% versus 58.8%) and non-SLN metastasis (48% versus 27%). The information gained by ALND had changed decisions for chemotherapy in 3% and no change of radiotherapy in Z0011 eligible patients. Further nodal positivity in completion ALND was not significantly associated with overall survival (p = 0.86) and disease-free survival (p = 0.5).

CONCLUSION

Z0011 eligible Indian EBC patients are significantly different from the Z0011 study population, with younger age of presentation, higher grade, a higher rate of both SLN macro metastasis and non-SLN positivity. The impact of non-sentinel metastasis on adjuvant treatment decisions and survival is minimal.

Application of the ACOSOG Z0011 criteria to Chinese patients with breast cancer: a prospective study

Background

Although the ACOSOG Z0011 study showed that axillary lymph node dissection (ALND) could be avoided in a specific population of sentinel lymph node-positive patients, it is not widely accepted by Chinese surgeons. We conducted a prospective single-arm study to confirm whether or not the results of Z0011 are applicable to Chinese patients.

Methods

Patients conforming to the Z0011 criteria were prospectively enrolled at the Peking University People’s Hospital Breast Center from November 2014 to June 2019. The clinicopathological features of the study group were compared with those of the Z0011 study group. Lymphedema after surgery, the incidence of local-regional recurrence, and survival were analyzed.

Results

One hundred forty-two patients who met the Z0011 eligibility criteria were enrolled in this study; 115 underwent sentinel lymph node biopsy (SLNB) alone. Compared with the Z0011 trial, younger patients were included (median age, 52 [26–82] years vs 54 [25–90] years; P = 0.03). For clinical T stage, tumor histology, hormone status, lymphovascular invasion, and the number of positive sentinel lymph nodes (SLNs), no statistically significant differences were observed. More patients received adjuvant chemotherapy and endocrine therapy in this study (90.85% vs 58.0% and 80.99% vs 46.6% respectively, P <0.001). A similar percentage of patients received radiotherapy, but more nodal radiotherapy procedures were carried out in our study (54.5% vs 16.9%). After a median follow-up of 29 months, only 1 patient (0.9%) had ipsilateral breast tumor recurrence, and no regional recurrence occurred.

Conclusion

Our study showed that it is achievable to avoid ALND in patients eligible for Z0011 in China.

Trial registration

ClinicalTrials.gov. Registration number NCT03606616. Retrospectively registered on 31 July 2018.