Expanding Implementation of ACOSOG Z0011 in Surgeon Practice

Update on Sentinel Lymph Node Methods and Pathology in Breast Cancer

Breast cancer stands out as the most commonly diagnosed cancer among women globally. Precise lymph node staging holds critical significance for both predicting outcomes in early-stage disease and formulating effective treatment strategies to control regional disease progression in breast cancer patients. No imaging technique possesses sufficient accuracy to identify lymph node metastases in the early stages (I or II) of primary breast cancer. However, the sentinel node procedure emerges as a valuable approach for identifying metastatic axillary nodes. The sentinel lymph node is the hypothetical first lymph node or group of nodes draining a cancer. In case of established cancerous dissemination, it is postulated that the sentinel lymph nodes are the target organs primarily reached by metastasizing cancer cells from the tumor. The utilization of the sentinel node technique has brought about changes in the assessment of lymph nodes. It involves evaluating the sentinel node during surgery, enabling prompt lymph node dissection when the sentinel node procedure is positive. Additionally, histological ultra-stratification is employed to uncover occult metastases. This review aims to provide an update of this valuable technique, with focus on the practical aspects of the procedure and the different histological protocols of sentinel node evaluation in breast cancer.

De-implementation of Axillary Dissection in Women Undergoing Mastectomy for Breast Cancer

BACKGROUND

Completion axillary lymph node dissection (cALND) was standard treatment for breast cancer with positive sentinel lymph nodes (SLNs) until 2011, when data from the Z11 and AMAROS trials challenged its survival benefit in early stage breast cancer. We assessed the contribution of patient, tumor, and facility factors on cALND use in patients undergoing mastectomy and SLN biopsy.

PATIENTS AND METHODS

Using the National Cancer Database, patients diagnosed from 2012 to 2017 who underwent upfront mastectomy and SLN biopsy with at least one positive SLN were included. A multivariable mixed effects logistic regression model was used to determine the effect of patient, tumor, and facility variables on cALND use. Reference effect measures (REM) were used to compare the contribution of general contextual effects (GCE) to variation in cALND use.

RESULTS

From 2012 to 2017, the overall use of cALND decreased from 81.3% to 68.0%. Overall, younger patients, larger tumors, higher grade tumors, and tumors with lymphovascular invasion were more likely to undergo cALND. Facility variables, including higher surgical volume and facility location in the Midwest, were associated with increased use of cALND. However, REM results showed that the contribution of GCE to the variation in cALND use exceeded that of the measured patient, tumor, facility, and time variables.

CONCLUSIONS

There was a decrease in cALND use during the study period. However, cALND was frequently performed in women after mastectomy found to have a positive SLN. There is high variability in cALND use, mainly driven by interfacility practice variation rather than specific high-risk patient and/or tumor characteristics.

The impact of intraoperative frozen section in patients with clinically node-negative breast cancer (cN0/ycN0) who received neoadjuvant systemic therapy

BACKGROUND

When surgical axillary staging reveals residual metastatic deposits in breast cancer (BC) patients who had received neoadjuvant chemotherapy (NACT), axillary lymphonodectomy is indicated. In this study, we investigate whether it is reasonable to perform intraoperative frozen section (FS) of the removed sentinel lymph nodes (SLNs) in cases where NACT had been administered in patients who had a clinically negative nodal status at the time of diagnosis.

PATIENTS AND METHODS

We analyzed data from 101 BCE patients with 103 carcinomas who were diagnosed between 2014 and 2021 and met the above-mentioned criteria.

RESULTS

In three cases (2.8% of the study group), histologically active tumor tissue was detected in the removed axillary LNs. Discontinuation of therapy/the use of a low-dose NACT regimen was a significant factor for positive LNs (p = 0.02) at the subsequent surgical procedure; tumor progression during therapy approached borderline significance (p = 0.058). Among patients who had completed NACT with the planned standard dose regimen, and in which the primary tumors showed a response to therapy (n = 94), only one case had histologically detected residual metastases in the SLNs.

CONCLUSIONS

Certified breast centers aim to improve the outcome of the patients. However, these specialized centers should also focus on economic aspects. This means that diagnostic and therapeutic procedures should be continuously critically reviewed in order to avoid unnecessary expenses. In BC patients with clinically node negative disease who completed NACT as planned and in which the tumor showed a good response to therapy, time consuming and costly FS of the SLNs removed should be omitted.

Update on sentinel node pathology in breast cancer

Pathologic examination of the sentinel lymph nodes (SLNs) in patients with breast cancer has been impacted by the publication of practicing changing trials over the last decade. With evidence from the ACOSOG Z0011 trial to suggest that there is no significant benefit to axillary lymph node dissection (ALND) in early-stage breast cancer patients with up to 2 positive SLNs, the rate of ALND, and in turn, intraoperative evaluation of SLNs has significantly decreased. It is of limited clinical significance to pursue multiple levels and cytokeratin immunohistochemistry to detect occult small metastases, such as isolated tumor cells and micrometastases, in this setting. Patients treated with neoadjuvant therapy, who represent a population with more extensive disease and aggressive tumor biology, were not included in Z0011 and similar trials, and thus, the evidence cannot be extrapolated to them. Recent trials have supported the safety and accuracy of sentinel lymph node biopsy (SLNB) in these patients when clinically node negative at the time of surgery. ALND remains the standard of care for any amount of residual disease in the SLNs and intraoperative evaluation of SLNs is still of value for real time surgical decision making. Given the potential prognostic significance of residual small metastases in treated lymph nodes, as well as the decreased false negative rate with the use of cytokeratin immunohistochemistry (IHC), it may be reasonable to maintain a low threshold for the use of cytokeratin IHC in post-neoadjuvant cases. Further recommendations for patients treated with neoadjuvant therapy await outcomes data from ongoing clinical trials. This review will provide an evidence-based discussion of best practices in SLN evaluation.

Survival and recurrence with or without axillary dissection in patients with invasive breast cancer and sentinel node metastasis

To evaluate overall survival and locoregional recurrence between patients with invasive breast tumours and sentinel node metastasis undergoing sentinel lymph node dissection (SLND) alone and those undergoing complete axillary lymph node dissection (ALND). In this retrospective cohort study, we reviewed the medical records of patients with invasive breast carcinoma who underwent lumpectomy at a public university hospital in Brazil between 2008 and 2018. We evaluated the overall survival and the locoregional recurrence using Kaplan-Meier and Cox regression analyses, respectively. Overall, 97 participants who underwent lumpectomy were enroled; 41 in the ALND group, and 56 in the SLND group, according to Z0011 criteria. Only 17% of the patients in the ALND group had an additional biopsy-proven axillary disease, and 83% were treated with complete dissection unnecessarily. The 5-year survival rates were 80.1% and 87.5% for SLND and ALND, respectively (p = 0.376). Locoregional recurrence was rare (1.7% and 7.3% in the SLND and ALND, respectively; p = 0.3075). Overall survival and locoregional recurrence were similar between the two groups. The de-escalation of ALND to SLND in women with metastasis in the sentinel lymph node treated with conservative surgery and radiotherapy that meet the Z0011 criteria is feasible even in developing countries.

Trends and Outcomes Associated With Axillary Management of Males With Clinical N0 Breast Cancer-An NCDB Analysis

BACKGROUND

Sentinel Lymph Node Biopsy (SLNB) is standard of care for women with clinically N0 breast cancer. However, there are no randomized controlled studies in men determining optimal surgical axillary management.

METHODS

Using the National Cancer Database, males diagnosed from 2006-2016 with clinical T1-4 N0 tumors treated with primary surgery were identified and categorized by axillary management. Clinicopathologic variables were compared between two timeframes, 2006-2011 and 2012-2016. Survival analysis was performed.

RESULTS

We identified 2,646 males meeting criteria. Use of SLNB increased (65.9%-72.8%, P < 0.01). For those who underwent ALND, administration of radiation (31.1% versus 48.8%, P < 0.01) and endocrine therapy (70.2% versus 80.7%, P < 0.01) increased. There was no difference in survival between timeframes (P = 0.42). For those who underwent SLNB, tumor grade (P = 0.02) and pathologic T stage (P < 0.01) were higher and more patients underwent mastectomy (74.9% versus 79.4%, P = 0.02). Administration of chemotherapy decreased (35.1% versus 27.2%, P < 0.01) and endocrine therapy increased (72.1% versus 81.3%, P < 0.01). Survival of those who underwent sentinel lymph node biopsy (SLNB) diagnosed 2012-2016 was worse than those diagnosed 2006-2011 (P = 0.01).

CONCLUSIONS

Use of SLNB alone has increased while ALND has declined in males with clinically N0 breast cancer. However, patients who underwent SLNB alone in the later time period had worse clinical characteristics and experienced differences in adjuvant therapy. This suggests increased acceptance of the use of SLNB for axillary management. Further analysis is warranted to evaluate methods of axillary staging and the impact on outcomes in males with breast cancer.

Trends in Axillary Management of Early Breast Cancer: a Questionnaire-Based Pattern of Practice Survey for India

Surgical management of breast cancer (BC) has evolved from radical surgeries to conservative with better cosmetic and comparable oncological outcomes. For axillary staging, it has evolved from axillary lymph node dissection (ALND) to sentinel lymph node biopsy (SLNB). No detailed information exists in terms of the clinical practice pattern of surgical management of axilla for BC patients in India. A questionnaire-based survey was developed. The survey was done at the annual meeting of the Association of Breast Surgeons of India (ABSI) in November 2018. Responses were recorded and analysed by SPSS 23. One hundred twelve out of 400 (28%) responded to the survey. Half of the respondents were surgical oncologist and 36.6% were performing > 150 BC surgeries/year. The primary technique for axillary staging in node-negative BC was SLNB for 68.5% of respondents. Majority of surgeons (47%) reported performing SLNB by methylene blue dye only. Unavailability of radioisotope (46.7%) and lack of frozen section (26.7%) were reported as two major barriers for not performing SLNB. Twenty-three percent did perform SLNB in post-NACT setting. Only 15.8% have omitted completion ALND in Z0011 trial eligible SLN-positive patients. 45.9% skipped completion ALND in SLN positive with micro metastasis only. Many surgeons in India are adopting SLNB as a method of axillary staging into their clinical practice. However, large number of surgeons still believe in conservative approach, most probably due to unavailability of resources and lack of Indian data. Barrier identified in this survey may be useful for future development.

Surgeon decision-making for management of positive sentinel lymph nodes in the post-Multicenter Selective Lymphadenectomy Trial II era: A survey study

BACKGROUND AND OBJECTIVES

Completion lymph node dissection (CLND) did not improve melanoma-specific survival for patients with sentinel lymph node (SLN)-positive melanoma in the second Multicenter Selective Lymphadenectomy Trial (MSLT-II). We assessed surgeons' awareness of MSLT-II and its impact on CLND recommendations.

METHODS

An anonymous online cross-sectional survey of the Society of Surgical Oncology membership evaluated surgeon thresholds in offering CLND using patient scenarios and clinicopathologic characteristics ranking.

RESULTS

Of the 2881 e-mails delivered, 146 surgeons (5.1%) completed all seven scenarios. Most (129 of 131, 98%) were aware of MSLT-II and 125 (95%) found it practice-changing. Specifically, 52% (65 of 125) always, 40% usually, 6% rarely, and 3% never offered CLND before MSLT-II. Meanwhile, 4% always, 9% usually, 78% rarely, and 8% never offer CLND now, after MSLT-II (p < .0001). The most important clinicopathologic factors in determining CLND recommendations were extracapsular extension, number of positive SLN, and SLN tumor deposit size, while primary tumor mitotic index and nodal basin location were the least important. Surgical oncology fellowship training, melanoma patient volume, and academic center practice also influenced CLND recommendations.

CONCLUSIONS

Most surgeon respondents are aware of MSLT-II, but its application in practice varies according to several clinicopathologic and surgeon factors.

Deimplementation of the Choosing Wisely Recommendations for Low-Value Breast Cancer Surgery

Importance

Overtreatment of early-stage breast cancer results in increased morbidity and cost without improving survival. Major surgical organizations participating in the Choosing Wisely campaign identified 4 breast cancer operations as low value: (1) axillary lymph node dissection for limited nodal disease in patients receiving lumpectomy and radiation, (2) re-excision for close but negative lumpectomy margins for invasive cancer, (3) contralateral prophylactic mastectomy in patients at average risk with unilateral cancer, and (4) sentinel lymph node biopsy in women 70 years or older with hormone receptor-positive cancer.

Objective

To evaluate the extent to which these procedures have been deimplemented, determine the implications of decreased use, and recognize possible barriers and facilitators to deimplementation.

Evidence Review

A systematic review of published literature on use trends in breast surgery was performed in accordance with PRISMA guidelines. The Ovid, Embase, Cumulative Index to Nursing and Allied Health Literature, and Cochrane databases were searched for original research with relevance to the Choosing Wisely recommendations of interest. Eligible studies were examined for data about use, and any patient-level, clinician-level, or system-level factors associated with use.

Findings

Concordant with recommendations, national rates of axillary lymph node dissection for patients with limited nodal disease have decreased by approximately 50% (from 44% in 2011 to 30% to 34% in 2012 and 25% to 28% in 2013), and national rates of lumpectomy margin re-excision have decreased by nearly 40% (from 16% to 34% before to 14% to 18% after publication of a consensus statement). Conversely, national rates of contralateral prophylactic mastectomy continue to rise each year, accounting for up to 30% of all mastectomies for breast cancer (range in all mastectomy cases: 2010-2012, 28%-30%; 1998, <2%), and rates of sentinel lymph node biopsy in women 70 years or older with low-risk breast cancer are persistently greater than 80% (range, 80%-88%). Factors associated with high rates of contralateral prophylactic mastectomy use are younger age, white race, increased socioeconomic status, and the availability of breast reconstruction; limited data exist on factors associated with high rates of sentinel lymph node biopsy in women 70 years or older. Successful deimplementation of axillary lymph node dissection and lumpectomy margin re-excision were associated with decreased costs and improved patient-centered outcomes.

Conclusions and Relevance

This review demonstrates variable deimplementation of 4 low-value surgical procedures in patients with breast cancer. Addressing specific patient-level, clinician-level, and system-level barriers to deimplementation is necessary to encourage shared decision-making and reduce overtreatment.

Axillary Management in Women with Early Breast Cancer and Limited Sentinel Node Metastasis: A Systematic Review and Metaanalysis of Real-World Evidence in the Post-ACOSOG Z0011 Era

BACKGROUND

After the publication of the Z0011 trial, the American Society of Clinical Oncology published an updated clinical practice guideline stating that clinicians should not recommend axillary lymph node dissection (ALND) for early-stage breast cancer patients with the involvement of one or two sentinel lymph nodes (SLNs). However, these recommendations have been challenged because they were mainly based on data from limited studies. The aim of the current study is to systematically compare the real-world outcomes of SLN biopsy (SLNB) alone and SLNB + ALND in patients with early-stage breast cancers and limited positive SLN metastasis in the post-Z0011 era PATIENTS AND METHODS: We searched articles in the PubMed, EMBASE, and Cochrane library databases. The primary endpoints were overall survival (OS) and disease-free survival (DFS). The secondary endpoints were recurrence rate and the incidence of lymphedema.

RESULTS

One randomized controlled trial and six retrospective studies with 8864 patients were retrieved. For patients with early-stage breast cancer with one or two SLN metastases, receiving SLNB alone showed no significant difference in OS, DFS, and recurrence rate compared with receiving SLNB + ALND. The incidence of lymphedema in patients who received SLNB alone was significantly lower than those who received SLNB + ALND (odds ratio 1.95, 95% confidence interval 1.02-3.71).

CONCLUSIONS

Current real-world evidence proved that the Z0011 strategy is safe with respect to survival outcomes and effective in reducing the incidence of lymphedema. ALND should be avoided in patients with early-stage breast cancer with one or two SLN metastases in the post-Z0011 era.

National Trend of Axillary Management in Clinical T3/T4 N0 Patients Having Breast Conserving Therapy

BACKGROUND

The ACOSOG Z0011 trial has essentially eliminated axillary lymph node dissection (ALND) in breast conserving therapy (BCT) patients with clinical T1/T2 and 1-2 positive sentinel lymph nodes (SLNs). Currently, ALND is recommended for positive SLNs unless ACOSOG Z0011 criteria are applicable. We aimed to assess the national trends and axillary management before and after the publication of ACOSOG Z0011 for larger tumors.

METHODS

An IRB-approved study evaluated the National Cancer Database from 2006 to 2016. Women with clinical T3/T4, N0 who otherwise fit ACOSOG Z0011 criteria were included. Neoadjuvant systemic therapy or known nodal disease was excluded. Clinicopathologic data were compared between two timeframes based on ACOSOZ Z0011 publication and by axillary management. Patients were categorized into SLNB alone (1-5 lymph nodes examined) and ALND (≥10 lymph nodes examined) groups.

RESULTS

A total of 230 women fit inclusion criteria, of whom 36% underwent ALND. ALND use decreased from 54% in 2006 to 14% in 2016 (P < 0.01). Comparing ALND to SLNB alone within the pre-Z0011 era, comprehensive community cancer programs had higher proportions of ALND, whereas academic centers had higher rates of SLND alone (P = 0.03). Comparing similar axillary management between eras, SLNB-alone patients in the post-Z0011 era had higher pT and pN stages, were less likely to be Her2 positive, and were more likely to receive systemic treatment.

CONCLUSIONS

There is a national trend to forgo ALND in women who have tumors larger than those included in the Z0011 criteria without any clear clinicopathologic indications.

De-escalation of axillary surgery in breast cancer patients treated in the neoadjuvant setting: a Dutch population-based study

PURPOSE

An overall trend is observed towards de-escalation of axillary surgery in patients with breast cancer. The objective of this study was to evaluate this trend in patients treated with neoadjuvant systemic therapy (NST).

METHODS

Patients with cT1-4N0-3 breast cancer treated with NST (2006-2016) were selected from the Netherlands Cancer Registry. Patients were classified by clinical node status (cN) and type of axillary surgery. Uni- and multivariable logistic regression analyses were performed to determine the clinicopathological factors associated with performing ALND in cN+ patients.

RESULTS

A total of 12,461 patients treated with NST were identified [5830 cN0 patients (46.8%), 6631 cN+ patients (53.2%)]. In cN0 patients, an overall increase in sentinel lymph node biopsy (SLNB) only (not followed by ALND) was seen from 11% in 2006 to 94% in 2016 (p < 0.001). SLNB performed post-NST increased from 33 to 62% (p < 0.001). In cN+ patients, an overall decrease in ALND was seen from 99% in 2006 to 53% in 2016 (p < 0.001). Age (OR 1.01, CI 1.00-1.02), year of diagnosis (OR 0.47, CI 0.44-0.50), HER2-positive disease (OR 0.62, CI 0.52-0.75), clinical tumor stage (T2 vs. T1 OR 1.32, CI 1.06-1.65, T3 vs. T1 OR 2.04, CI 1.58-2.63, T4 vs. T1 OR 6.37, CI 4.26-9.50), and clinical nodal stage (N3 vs. N1 OR 1.65, CI 1.28-2.12) were correlated with performing ALND in cN+ patients.

CONCLUSIONS

ALND decreased substantially over the past decade in patients treated with NST. Assessment of long-term prognosis of patients in whom ALND is omitted after NST is urgently needed.

[Strategies in case of metastatic sentinel lymph node in breast cancer]

Management strategy of micro or macro metastatic sentinel lymph node(s) (SLNs) in breast cancer has dramatically changed over the past ten years and the publication of five randomized trials results: ACOSOG Z0011, IBCSG 23-01, and AATRM comparing axillary lymph node dissection (ALND) versus SLNs biopsy alone; and AMAROS and OTOASOR comparing ALND versus axillary radiotherapy. Despite methodological limitations of several of these trials, notably ACOSOG Z0011, the international recommendations (ASCO, NCCN) and the expert consensus of St Gallen do not recommend the performance of a complementary ALND in case of macro or micro metastatic SLN, if all ACOSOG Z0011 inclusion criteria are met. Moreover, in the context of a mastectomy, with one or two positive SLN and a wall irradiation indication, an axillary radiotherapy can be proposed as an alternative to ALND. Additionally, ALND is also indicated in extracapsular involvement or when three or more SLNs are metastatic. This change in strategy led to a significant decrease on the number of ALNDs performed and resulted on the abandon of SLNs extemporaneous examination. In France, there are no national recommendations on axillary management in the context of SLN involvement. Moreover, a multitude of different local guidelines, led to very heterogeneous practices in our country. The next evolution on axillary management strategy will be the implementation of a SLNs procedure after neoadjuvant chemotherapy (NAC) for patients with lymph node involvement proven before NAC and for whom NAC has allowed axillary downstaging.

Breast cancer metastasis through the lympho-vascular system

Breast cancer metastasizes through the lymphovascular system to the regional lymph nodes in the axilla and to both visceral and non-visceral sites. Renewed interest in the route by which tumor cells gain access to blood and lymphatic capillaries are the subject of research at mechanical, anatomic, pathologic, genetic, epidemiologic and molecular levels. Two papers presented at the 7th International Symposium on Cancer Metastasis in San Francisco showed tumor cells entering the systemic circulation through the sentinel lymph node. This information challenges the current paradigm where clinicians believe that access is gained through intra- and peri-tumoral blood vessels and that metastasis to axillary lymph nodes is an interesting epi-phenomenon. The sentinel lymph node era has changed the modern surgical approach to the axilla and the basis of this change is summarized in this paper. A new approach to the management of axillary metastases after systemic therapy relies on determining whether there is a complete pathologic response; if no tumor is found in the previously biopsied node, a complete axillary lymph node dissection may be avoided. African American women seem to inherit a trait from West African ancestors and tend to develop more lethal types of breast cancer. These tumors may have a molecular machinery that enhances their ability to metastasize to visceral sites and future research may unearth the mechanisms for this phenomenon.