Potential Impact of the Z0011 Trial on the Omission of Axillary Dissection: A Retrospective Cohort Study

OBJECTIVE

 To evaluate the number of patients with early-stage breast cancer who could benefit from the omission of axillary surgery following the application of the Alliance for Clinical Trials in Oncology (ACOSOG) Z0011 trial criteria.

METHODS

 A retrospective cohort study conducted in the Hospital da Mulher da Universidade Estadual de Campinas. The study population included 384 women diagnosed with early-stage invasive breast cancer, clinically negative axilla, treated with breast-conserving surgery and sentinel lymph node biopsy, radiation therapy, chemotherapy and/or endocrine therapy, from January 2005 to December 2010. The ACOSOG Z0011 trial criteria were applied to this population and a statistical analysis was performed to make a comparison between populations.

RESULTS

 A total of 384 patients underwent breast-conserving surgery and sentinel lymph node biopsy. Of the total number of patients, 86 women underwent axillary lymph node dissection for metastatic sentinel lymph nodes (SNLs). One patient underwent axillary node dissection due to a suspicious SLN intraoperatively, thus, she was excluded from the study. Among these patients, 82/86 (95.3%) had one to two involved sentinel lymph nodes and met the criteria for the ACOSOG Z0011 trial with the omission of axillary lymph node dissection. Among the 82 eligible women, there were only 13 cases (15.9%) of lymphovascular invasion and 62 cases (75.6%) of tumors measuring up to 2 cm in diameter (T1).

CONCLUSION

 The ACOSOG Z0011 trial criteria can be applied to a select group of SLN-positive patients, reducing the costs and morbidities of breast cancer surgery.

In breast cancer patients sentinel lymph node metastasis characteristics predict further axillary involvement

The aim of the study was to correlate various primary tumor characteristics with lymph node status, to examine sentinel lymph node (SLN) metastasis size and non-SLN axillary involvement, to look for a cut-off size/number value possibly predicting additional axillary involvement with more accuracy and to examine the relationship of SLN metastasis size to overall survival. Of 301 patients who underwent SLN biopsy, 75 had positive SLNs. The size of the metastases was measured. For different size categories, association with the prevalence of non-SLN metastases was assessed. Associations between metastasis size and tumor characteristics and overall survival (OS) were studied. The prevalence of axillary lymph node (ALN) involvement was not significantly different between cases with micrometastasis or macrometastasis in SLNs (p = 0.124). However, for metastases larger than 6, 7, and 8 mm, the prevalence of ALN involvement was significantly higher (p = 0.046, 0.022, and 0.025). OS was significantly lower in SLN-positive than in SLN-negative cases (p = 0.0375). Primary tumor size larger than 20 mm was associated with a significantly higher incidence of SLN metastasis (p < 0.001), and primary tumor size over 26 mm was associated with additional positive non-SLN (p < 0.001). Higher mitotic index (≥ 7) in primary tumors was significantly (p < 0.001) associated with ALN involvement in SLN-positive cases, whereas higher Ki67 labeling index was not significantly correlated with SLN or ALN involvement. Lymphovascular invasion (LVI) in primary tumors was significantly correlated with SLN positivity (p < 0.001) but not with further ALN involvement or OS. Tumor size and LVI are predictive for SLN metastasis. Mitotic index, primary tumor size, and larger volume SLN involvement are determinants of further ALN involvement. SLN metastasis size over 6 mm is a strong predictor of further axillary involvement. OS is shorter in the presence of positive SLN.

Clinical significance and management of sentinel node micrometastasis in invasive breast cancer

Axillary node status is one of the most important prognostic indicators in patients with invasive breast cancer. Sentinel node biopsy allows an exhaustive examination of the lymph node and has led to an increased detection rate of small tumor deposits. Patients with micrometastatic deposits can have nonsentinel node involvement, including macrometastatic deposits. Sentinel node micrometastases are associated with an adverse impact on disease recurrence and survival. Axillary dissection does not offer an advantage in reducing the incidence of disease recurrence or survival. However, the long-term outcomes can be improved with the use of adjuvant chemotherapy, and it would be reasonable to consider systemic treatment in these patients.

Axillary recurrence after a tumor-positive sentinel lymph node biopsy without axillary treatment: a review of the literature

Background

Sentinel lymph node biopsy (SLNB) has become standard of care as a staging procedure in patients with invasive breast cancer. A positive SLNB allows completion axillary lymph node dissection (cALND) to be performed. The axillary recurrence rate (ARR) after cALND in patients with positive SLNB is low. Recently, several studies have reported a similar low ARR when cALND is not performed. This review aims to determine the ARR when cALND is omitted in SLNB-positive patients.

Methods

A literature search was performed in the PubMed database with the search terms “breast cancer,” “sentinel lymph node biopsy,” “axillary” and “recurrence.” Articles with data regarding follow-up of patients with SLNB-positive breast cancer were identified. To be eligible, patients should not have received cALND and ARR should be reported.

Results

Thirty articles were analyzed. This resulted in 7,151 patients with SLNB-positive breast cancer in whom a cALND was omitted (median follow-up of 45 months, range 1–142 months). Overall, 41 patients developed an axillary recurrence. 27 studies described 3,468 patients with micrometastases in the SLNB, of whom 10 (0.3 %) developed an axillary recurrence. ARR varied between 0 and 3.7 %. Sixteen studies described 3,268 patients with macrometastases, 24 (0.7 %) axillary recurrences were seen. ARR varied between 0 and 7.1 %. Details regarding type of surgery and adjuvant treatment were lacking in the majority of studies.

Conclusions

ARR appears to be low in SLNB-positive patients even when a cALND is not performed. Withholding cALND may be safe in breast cancer selected patients such as those with isolated tumor cells or micrometastatic disease.

Prognostic impact and therapeutic implications of sentinel lymph node micro-metastases in early-stage breast cancer patients

The prognostic value of sentinel lymph node (SLN) micro-metastases and the question whether patients with SLN micro-metastases should undergo axillary lymph node dissection remain a matter of great debate. Based on the current literature and on our own data, we provide suggestive evidence that SLN micro-metastases in early stage breast cancer patients appear to have prognostic value and should impact the decision-making regarding adjuvant therapy, however, do not necessarily require further surgical treatment.

A 10-year trend analysis of sentinel lymph node frozen section and completion axillary dissection for breast cancer: are these procedures becoming obsolete?

BACKGROUND

Recent results from the ACOSOG Z0011 trial question the use of intraoperative frozen section (FS) during sentinel lymph node (SLN) biopsy and the role of axillary dissection (ALND) for SLN-positive breast cancer patients. Here we present a 10-year trend analysis of SLN-FS and ALND in our practice.

METHODS

We reviewed our prospective SLN database over 10 years (1997-2006, 7509 SLN procedures) for time trends and variation between surgeons in the use of SLN-FS and ALND in patients with cN0 invasive breast cancer.

RESULTS

Use of SLN-FS decreased from 100% to 62% (P < 0.0001) and varied widely by surgeon (66% to 95%). There were no statistically significant trends in the performance of ALND for patients with SLN metastases detected by FS (n = 1370, 99-99%) or routine hematoxylin and eosin (H&E) (n = 333; 69-77%), but only for those detected by serial section H&E with or without immunohistochemistry (n = 438; 73-48%; P = 0.0054) or immunohistochemistry only (n = 294; 48-28%; P < 0.0001). These trends coincided with an increase in the proportion of completion versus immediate ALND (30-40%; P = 0.0710).

CONCLUSIONS

Over 10 years, we have observed a diminishing rate of SLN-FS and, for patients with low-volume SLN metastases, fewer ALND, trends that suggest a more nuanced approach to axillary management. If the Z0011 selection criteria had been applied to our cohort, 66% of SLN-FS (4159 of 6327) and 48% of ALND (939 of 1953) would have been avoided, sparing 13% of all patients the morbidity of ALND.

Axillary recurrences following positive sentinel lymph node biopsy with individual tumor cells or micrometastases and no axillary dissection

The increased use of sentinel lymph node (SLN) excision for staging the axilla in women with breast cancer has benefited women by lowering morbidity and at the same time has raised issues related to the extent of treatment needed to the nodal basin. This is of particular concern when micrometastases or isolated tumor cells are found in the sentinel nodes on the final pathology. The probability of finding metastatic disease in non-sentinel lymph nodes (NSLN) ranges from 0 to 20% with only micrometastatic deposits in the SLN. Very low rates (0-3.7%) of axillary recurrence have been reported in selected patients with micrometastases tumor in sentinel nodes who have not had a completion axillary node dissection (ALND). Risk factors for additional positive NSLN include primary tumor size, the presence of lymphovascular invasion and the size of the SN metastatic deposit. Currently, the decision to not complete the ALND when micrometastic disease is found in the SLN should be made on a case-by-case basis. One should consider the tumor characteristics, findings within the SLN, and a multidisciplinary treatment plan. Clinical trial results may help to resolve the dilemma. There appears to be a low risk for axillary recurrence.

Sentinel node biopsy for breast cancer patients: issues for discussion and our practice

Sentinel node biopsy has been established for several years now as a standard procedure of breast cancer surgery, but there are several variations of the indications and the technique used. This paper provides information regarding several issues of debate for its application as are the selection criteria, the application to patients with multifocal/multicentric breast cancer or DCIS, postneoadjuvant chemotherapy, the necessary number of nodes to be biopsied, the need for lymphoscintigraphy, the technique for frozen section, the factors that may predict nonsentinel nodes (NSNs) involvement, the value of micrometastasis and isolated tumour cells, the internal mammary chain sentinel nodes, and finally the axillary recurrence after SLNB. Our view for these issues is included together with our experience of 430 SLNBs.