Relevance of the American College of Surgeons Oncology Group Z0011 Trial to breast cancer in the Australian setting

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.

ACOSOG Z-0011 criteria impact on axillary surgery for early breast cancer in clinical practice: Evaluation in a retrospective cohort of 1900 patients

BACKGROUND

There is a trend towards de-escalation in early breast cancer axillary surgery. In the American College of Surgeons Oncology Group (ACOSOG) Z-0011 trial, observation was shown to be non-inferior in terms of overall survival to complementary axillary lymph node dissection (cALND) in patients with up to two sentinel lymph node (SLN) metastases. The study included patients with T1-T2 invasive breast cancer, clinically node negative, undergoing breast-conserving surgery with SLN biopsy, followed by systemic therapy and radiotherapy. The aim of our study was to evaluate the impact of applying these ACOSOG Z-0011 inclusion criteria in routine practice.

PATIENTS AND METHODS

This retrospective observational study was conducted in a French comprehensive cancer center where patients treated for breast cancer with primary surgery were prospectively included between 2010 and 2016. Patients meeting ACOSOG Z-0011 inclusion criteria were analyzed.

RESULTS

Among the 1900 included patients, 1497 (79 %) met the ACOSOG Z-0011 criteria before surgery. Of these, 390 (20 %) had one or two metastatic SLN and could have avoided cALND. Out of these patients, 319 (81 %) presented cT1 tumors. During the study period, cALND was performed in 320 (82 %) patients and was free of metastases in 80 % of cases, having an impact on eligibility for adjuvant chemotherapy in only 3 (0.8 %) patients.

CONCLUSIONS

In situations of primary breast cancer surgery, use of ACOSOG Z-0011 criteria could reduce the rate of cALND by 20 %. Further studies are needed to help select patients for whom abstention from any axillary surgery would be reasonable.

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

The American College of Surgeons Oncology Group Z0011 Trial demonstrated that early breast cancer patients with positive axillary sentinel lymph nodes treated with breast-conserving surgery and breast radiotherapy had no additional oncologic benefit of proceeding to an axillary lymph node dissection (ALND). The extent to which practice has changed in Australia remains unclear. The aim of this study was to investigate the effect of the Z0011 trial on the management of positive axillary sentinel nodes at an Australian institutional level. We reviewed all breast cancer cases treated at the Sydney Adventist Hospital over a 10-year period from 1 January 2008 to 31 December 2017. Patients who fulfilled the Z0011 trial criteria were selected. These patients were divided into two groups according to the year of surgery, before and after 1 January 2011 when the Z0011 study was published. Clinicopathologic data and axillary surgical management were compared. Of the 237 patients fulfilling the Z0011 trial criteria, there were 73 patients before and 158 patients after 1 January 2011. In the earlier group the rate of proceeding to an ALND following a positive sentinel node was 78.1% compared to 43.7% in the latter group (P < 0.0001). There was a significant decline in the rate of ALND over this 10-year period (r = -0.79, P = 0.006). The Z0011 trial has influenced the surgical management of the axilla leading to a significant reduction in the rate of an ALND in patients fulfilling the Z0011 trial criteria at our institution.

Could axillary clearance be avoided in clinically node-negative breast cancer patients with positive nodes diagnosed by ultrasound guided biopsy in the post-ACOSOG Z0011 era?

BACKGROUND AND OBJECTIVES

The role of ultrasound (US) guided biopsy in selecting patients for an upfront lymph node dissection (ALND) has been controversial following the publication of the American College of Surgeons (ACOSOG) Z0011 data. The purpose of this study was to investigate if patients with positive axillary lymph nodes (LNs) proven by US guided biopsy should be recommended for ALND and to analyze the utility of preoperative US and US guided biopsy in planning axillary surgery to avoid both unnecessary ALND and unnecessary SLNB.

METHODS

Patients with a positive preoperative LN biopsy were identified and evaluated to determine their suitability for inclusion according to the criteria proposed in the Z0011 data. The correlation of the number of suspicious nodes found using US with the number of positive nodes on ALND was studied.

RESULTS

A total of 261 breast cancer patients who had a positive preoperative LN needle biopsy were identified, among them, 79 patients with cT1-2N0 breast cancer and ALND were enrolled in the study. Thirty-one patients (39.2%) had ≤2 positive nodes identified in pathology and 10 patients (12.7%) met all of the Z0011 criteria and might have been spared ALND. A significantly greater proportion of women with ≥3 positive nodes during ALND had >1 abnormal LN identified using US compared to women with ≤2 positive LNs found using ALND (66.7% vs. 6.5%, p<0.0001).

CONCLUSION

US with needle biopsy is valuable to patients with multiple suspicious nodes found using US while SLND without US guided needle biopsy is suggested if only one abnormal LN is detected on US in the post-Z0011 era.

Axillary Dissection and Nodal Irradiation Can Be Avoided for Most Node-positive Z0011-eligible Breast Cancers: A Prospective Validation Study of 793 Patients

OBJECTIVE

To determine rates of axillary dissection (ALND) and nodal recurrence in patients eligible for ACOSOG Z0011.

BACKGROUND

Z0011 demonstrated that patients with cT1-2N0 breast cancers and 1 to 2 involved sentinel lymph nodes (SLNs) having breast-conserving therapy had no difference in locoregional recurrence or survival after SLN biopsy alone or ALND. The generalizability of the results and importance of nodal radiotherapy (RT) is unclear.

METHODS

Patients eligible for Z0011 had SLN biopsy alone. Prospectively defined indications for ALND were metastases in ≥3 SLNs or gross extracapsular extension. Axillary imaging was not routine. SLN and ALND groups and radiation fields were compared with chi-square and t tests. Cumulative incidence of recurrences was estimated with competing risk analysis.

RESULTS

From August 2010 to December 2016, 793 patients met Z0011 eligibility criteria and had SLN metastases. Among them, 130 (16%) had ALND; ALND did not vary based on age, estrogen receptor, progesterone receptor, or HER2 status. Five-year event-free survival after SLN alone was 93% with no isolated axillary recurrences. Cumulative 5-year rates of breast + nodal and nodal + distant recurrence were each 0.7%. In 484 SLN-only patients with known RT fields (103 prone, 280 supine tangent, 101 breast + nodes) and follow-up ≥12 months, the 5-year cumulative nodal recurrence rate was 1% and did not differ significantly by RT fields.

CONCLUSIONS

We confirm that even without preoperative axillary imaging or routine use of nodal RT, ALND can be avoided in a large majority of Z0011-eligible patients with excellent regional control. This approach has the potential to spare substantial numbers of women the morbidity of ALND.

Different outcome in node-positive breast cancer patients found by axillary ultrasound or sentinel node procedure

Background

The Z0011 trial initiated a paradigm shift in the axillary treatment of breast cancer patients with a positive sentinel lymph node biopsy (SLNB), disregarding patients with a positive ultrasound-guided lymph node biopsy (UGLNB). We examined whether relevant differences exist between these patients to determine if the conclusions of the ACOSOG Z0011 trial are applicable to UGLNB-positive patients.

Methods

Patients diagnosed with invasive breast cancer in the Netherlands between January 2008 and December 2014 were selected from the Netherlands Cancer Registry.

Results

A total of 11,820 cases were included: 9149 cases in the SLNB group and 2671 in the UGLNB group. Multivariate analyses showed that UGLNB-positive patients were older (p < 0.001), more likely to have a poorly differentiated tumor (p < 0.001), had a negative hormone receptor status (p < 0.001), and more often had extensive nodal involvement (p < 0.001). However, they were less likely to undergo adjuvant radiation (p = 0.004) or systemic therapy (p < 0.001). Even after adjusting for these factors, UGLNB-positive patients had a worse overall survival (HR = 1.38; 95% CI 1.23–1.56) than SLNB-positive patients.

Conclusion

This nationwide retrospective study shows that young patients found positive by UGLNB have less favorable disease characteristics and a worse prognosis compared to patients with a positive SLNB. Selection by ultrasound plays an important role when axillary treatment strategies are considered. Hence, the conclusions of the Z0011 trial cannot unconditionally be applied to patients with a positive UGLNB.

Potential impact of application of Z0011 derived criteria to omit axillary lymph node dissection in node positive breast cancer patients

BACKGROUND

The ACOSOG Z0011 trial, a randomized controlled trial among patients with sentinel node positive breast cancer treated with breast conserving therapy, concluded that axillary lymph node dissection (ALND) can be omitted in these patients. However, questions were raised on the general applicability if the results of the Z0011 trial. Therefore, the aim of this study was to assess the practice changing effect of the Z0011 trial by quantifying the proportion of all node positive breast cancer patients who meet the inclusion criteria which are based on the Z0011 trial, thus in whom an ALND could be omitted.

METHODS

A multicenter population based study including patients with clinical T1-2N0-1M0 invasive non-metastatic breast cancer, a positive sentinel node or ultrasound guided lymph node biopsy, treated with breast conserving therapy and adjuvant systemic therapy between January 2007 and December 2012.

RESULTS

A total of 11,031 patients had invasive breast cancer including 3051 cases treated with breast conserving therapy and adjuvant systemic therapy. Subsequently, 916 cases with a positive nodal status underwent an ALND of whom 558 cases (60.9%), representing 5.1% of the total breast cancer population, would potentially have fulfilled the Z0011 criteria.

CONCLUSION

Application of Z0011 based criteria is practice changing in nearly 61% of all node positive patients, which could result in omission of the ALND in a substantial number of patients in the future. Further research has to be performed on the applicability of these conclusions to other categories of breast cancer patients.

Management of Early Node-Positive Breast Cancer in Australia: A Multicentre Study

To examine practice patterns for breast cancer patients with limited sentinel node (SN) disease in light of the ACOSOG Z0011 results. Retrospective analysis of patients with T1-2 breast cancer and positive sentinel lymph node biopsy (SLNB) admitted between January 2009 and December 2012. Patient demographics, tumor characteristics, and treatments were recorded. Eight hundred positive SLNBs were identified. A total of 452 (56.5%) proceeded to completion axillary lymph node dissection (cALND). cALND rate decreased from 65.1% to 49.7% from 2009-2010 to 2011-2012. cALND was performed for micrometastasis or isolated tumor cells in 39.3% in 2009-2010 and 22.2% in 2011-2012, whereas for macrometastases the rates were 83.1% and 68.6%, respectively. cALND rates diminished for both Z0011-eligible and -ineligible patients. The ACOSOG Z0011 trial presentation and publication coincided with a reduction in cALND for breast cancer with limited nodal disease. There appears equipoise regarding management of macrometastatic SN disease.

Impact of American College of Surgeons Oncology Group Z11 on surgical training at an academic cancer center

BACKGROUND

The application of the American College of Surgeons Oncology Group Z0011 trial (Z11) has resulted in fewer completion axillary lymph node dissections (ALNDs) for select patients. We hypothesize that the application of Z11 may result in fewer ALND cases for surgeons in training.

METHODS

In the setting of an academic cancer center incorporating Z11 into routine practice, we compared the total number of ALND performed in a pre-Z11 period (January 2007-April 2011, 52 mo) and post-Z11 period (April 2011-February 2014, 34 mo). We also identified the number of patients in the post-Z11 era in whom ALND was omitted as a result of Z11. Clinical and pathologic characteristics among these groups were analyzed.

RESULTS

A total of 279 and 191 ALNDs were performed in the pre-Z11 and post-Z11 groups, respectively. Variables were similar among these groups with respect to demographics, tumor characteristics, and surgeries performed. There was no difference in the monthly rates of ALND between groups-5.37 cases/mo (pre-Z11) and 5.62 cases/mo (post-Z11), P = 0.52. We identified a total of 53 patients for whom ALND was omitted due to Z11 application in the post-Z11 period, representing a potential 21.7% decrease (53/191 + 53) in the number of ALNDs in this period.

CONCLUSIONS

Although the application of Z11 could potentially impact surgical training with a 21.7% decrease in ALND cases (53/191 + 53), the surgical case volume at an academic cancer center absorbs this decrease and maintains consistent levels of training for ALND.

The feasibility of the ACOSOG Z0011 Criteria to Chinese Breast Cancer Patients: A Multicenter Study

The aim of this study was to determine the feasibility of the Z0011 criteria to Chinese breast cancer patients. An survey about the Z0011 trial was distributed and we collected 658 consecutive patients with axillary lymph node dissection (ALND) after positive sentinel lymph node (SLN) biopsy from five centers’ databases and grouped them as eligible or ineligible for omitting ALND according to the Z0011 criteria. The eligible group was compared with the cohort included in the Z0011 trial and with the ineligible group. Of the 427 respondants, 106 (24.8%) and 130 (30.4%)would not routinely perform ALND in patients meeting Z0011 criteria before and after learning of the trial results, respectively. Among the 658 patients, 151 (22.9%) were eligible and 507 were ineligible for omitting ALND. The clinicopathologic factors were not statistically different between the eligible group and the Z0011 cohort. Compared with the eligible Group, the ineligible group had significantly more T2 and T3 stage tumors, positive lymph nodes(LNs) and positive non-sentinel lymph nodes (NSLNs) (P < 0.01). The findings suggest good exportability of the Z0011 criteria to Chinese patients omitting ALND, but application of Z0011 as national treatment guideline still needs additional time and effort.

A Paradigm Shift in Axillary Breast Cancer Treatment; From "Treat All-Except," Toward "Treat None-Unless"

The various pitfalls that exist in using predictive systems for sentinel node-positive breast cancer are described, to give insight into the background and building stones of these systems. The aim of this article was to make clinicians aware of these pitfalls before using them in the clinical decision-making process in individual patients with positive sentinel nodes. Besides these pitfalls, the implications concerning the results of the Z0011 trial as presented by Giuliano et al (Giuliano AE, et al. Locoregional recurrence after sentinel lymph node dissection with or without axillary dissection in patients with sentinel lymph node metastases: The American College of Surgeons Oncology Group Z0011 randomized trial. Ann Surg 2010; 252:426-32, discussion 432-3) are addressed, and we point out some important issues for debate, before implementation of the conclusions of that practice-changing trial into daily clinical breast cancer practice.